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Leal GC, Whitfield T, Praharaju J, Walker Z, Oxtoby NP. Crop filling: A pipeline for repairing memory clinic MRI corrupted by partial brain coverage. MethodsX 2024; 12:102542. [PMID: 38313693 PMCID: PMC10837087 DOI: 10.1016/j.mex.2023.102542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 12/28/2023] [Indexed: 02/06/2024] Open
Abstract
Data-driven solutions offer great promise for improving healthcare. However, standard clinical neuroimaging data is subject to real-world imaging artefacts that can render the data unusable for computational research and quantitative neuroradiology. T1 weighted structural MRI is used in dementia research to obtain volumetric measurements from cortical and subcortical brain regions. However, clinical radiologists often prioritise T2 weighted or FLAIR scans for visual assessment. As such, T1 weighted scans are often acquired but may not be a priority, resulting in artefacts such as partial brain coverage being systematically present in memory clinic data. Here we present "MRI Crop Filling", a pipeline to replace the missing T1 data with synthetic data generated from the T2 scan, making real-world clinical T1 data usable for computational research including the latest AI innovations. Our method consists of the following steps:•Register scans: T2 and (cropped) T1.•Synthesise a new T1 using an open source deep learning tool.•Replace missing (cropped) T1 data in original T1 scan and super-resolve to improve image quality.
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Affiliation(s)
- Gonzalo Castro Leal
- Department of Computer Science, UCL Centre for Medical Image Computing, University College London, London, UK
| | - Tim Whitfield
- Division of Psychiatry, University College London, London, UK
| | | | - Zuzana Walker
- Division of Psychiatry, University College London, London, UK
- Essex Partnership University NHS Foundation Trust, Essex, UK
| | - Neil P. Oxtoby
- Department of Computer Science, UCL Centre for Medical Image Computing, University College London, London, UK
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Roehl M, Conway M, Ghonim S, Ferreira PF, Nielles-Vallespin S, Babu-Narayan SV, Pennell DJ, Gatehouse PD, Scott AD. STEAM-SASHA: a novel approach for blood- and fat-suppressed native T1 measurement in the right ventricular myocardium. MAGMA 2024; 37:295-305. [PMID: 38216813 PMCID: PMC10995026 DOI: 10.1007/s10334-023-01141-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 12/07/2023] [Accepted: 12/11/2023] [Indexed: 01/14/2024]
Abstract
OBJECTIVE The excellent blood and fat suppression of stimulated echo acquisition mode (STEAM) can be combined with saturation recovery single-shot acquisition (SASHA) in a novel STEAM-SASHA sequence for right ventricular (RV) native T1 mapping. MATERIALS AND METHODS STEAM-SASHA splits magnetization preparation over two cardiac cycles, nulling blood signal and allowing fat signal to decay. Breath-hold T1 mapping was performed in a T1 phantom and twice in 10 volunteers using STEAM-SASHA and a modified Look-Locker sequence at peak systole at 3T. T1 was measured in 3 RV regions, the septum and left ventricle (LV). RESULTS In phantoms, MOLLI under-estimated while STEAM-SASHA over-estimated T1, on average by 3.0% and 7.0% respectively, although at typical 3T myocardial T1 (T1 > 1200 ms) STEAM-SASHA was more accurate. In volunteers, T1 was higher using STEAM-SASHA than MOLLI in the LV and septum (p = 0.03, p = 0.006, respectively), but lower in RV regions (p > 0.05). Inter-study, inter-observer and intra-observer coefficients of variation in all regions were < 15%. Blood suppression was excellent with STEAM-SASHA and noise floor effects were minimal. DISCUSSION STEAM-SASHA provides accurate and reproducible T1 in the RV with excellent blood and fat suppression. STEAM-SASHA has potential to provide new insights into pathological changes in the RV in future studies.
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Affiliation(s)
- Malte Roehl
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, UK
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Miriam Conway
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, UK
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Sarah Ghonim
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, UK
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Pedro F Ferreira
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, UK
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Sonia Nielles-Vallespin
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, UK
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Sonya V Babu-Narayan
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, UK
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Dudley J Pennell
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, UK
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Peter D Gatehouse
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, UK
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Andrew D Scott
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, UK.
- National Heart and Lung Institute, Imperial College London, London, UK.
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Lenham FM, Iball GR. Improving the quality of computed tomography brain images in the presence of cochlear implant induced metal artefacts through the additional use of tissue mimicking materials alongside metal artefact reduction software. Radiography (Lond) 2024; 30:813-820. [PMID: 38513334 DOI: 10.1016/j.radi.2024.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/15/2024] [Accepted: 03/08/2024] [Indexed: 03/23/2024]
Abstract
INTRODUCTION Metal artefact reduction software (MAR) can be used to improve Computed Tomography (CT) image quality in the presence of implanted metalwork; however, this software is not effective for superficial metallic structures such as cochlear implants (CI). This study aimed to investigate whether the effectiveness of MAR software could be improved for brain scans with CI present through the use of tissue mimicking materials (TMM) placed exteriorly to the implant. METHODS In this two-part study, a CI was positioned on the surface of water and anthropomorphic phantoms and imaged using a helical CT brain protocol. Three TMM, Superflab, Sure Thermal heat packs, and Bart's Bolus, were utilised and images were acquired to assess the resulting artefact reduction in terms of CT numbers, noise and artefact index (Aind). Changes in CTDIvol were assessed for the anthropomorphic phantom scans. RESULTS In the water phantom, statistically significant reductions in CT number (p = 0.038) and noise (p = 0.033) were observed for Superflab, whilst the heat packs produced similar significant reductions in CT number (p < 0.001) and noise (p = 0.001) for the anthropomorphic phantom images. Aind values were significantly reduced through the use of Superflab (p = 0.009) and the heat packs (p < 0.001). No significant effects were observed for Bart's Bolus. CTDIvol increases of generally less than 5% were observed for scans with TMM in place. CONCLUSION The additional use of TMM alongside MAR software yielded statistically significant reductions in CI induced metal artefacts on both water and anthropomorphic phantom scans with minimal dose increases. IMPLICATIONS FOR PRACTICE The extent of metal artefacts in clinical head scans with CI in place could be significantly reduced through combined use of TMM and MAR software, consequently providing greater diagnostic confidence in the images.
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Affiliation(s)
- F M Lenham
- Department of Medical Physics & Engineering, Old Medical School, Leeds General Infirmary, Leeds, LS1 3EX, UK.
| | - G R Iball
- Department of Medical Physics & Engineering, Old Medical School, Leeds General Infirmary, Leeds, LS1 3EX, UK; Faculty of Health Studies, University of Bradford, Bradford, BD7 1DP, UK.
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Pye J. Trees in trees a report from remote Australia. Plant Signal Behav 2023; 18:2286392. [PMID: 38059450 PMCID: PMC10761035 DOI: 10.1080/15592324.2023.2286392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 11/16/2023] [Indexed: 12/08/2023]
Abstract
Anemochory or Ornithochory does not adequately explain the amount, size or distribution of woody epiphytes here in outback NSW Australia. In a semi-arid ecosystem, epiphytes should be short-lived and randomly dispersed not clustered around old Aboriginal campsites or along their ancient paths aka songlines. These enduring trees in trees we call TinTs, have been here much longer than European Australians. We are hoping to attract archaeobotanical or ethnobotanical research to help us recover the knowledge of the ancestors or at least assist us in protecting these arboreal oddities from future resource extraction activities.
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Affiliation(s)
- Jane Pye
- Gingie Station 2422 Gingie Rd, Walgett, Australia
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Shiri I, Salimi Y, Maghsudi M, Jenabi E, Harsini S, Razeghi B, Mostafaei S, Hajianfar G, Sanaat A, Jafari E, Samimi R, Khateri M, Sheikhzadeh P, Geramifar P, Dadgar H, Bitrafan Rajabi A, Assadi M, Bénard F, Vafaei Sadr A, Voloshynovskiy S, Mainta I, Uribe C, Rahmim A, Zaidi H. Differential privacy preserved federated transfer learning for multi-institutional 68Ga-PET image artefact detection and disentanglement. Eur J Nucl Med Mol Imaging 2023; 51:40-53. [PMID: 37682303 PMCID: PMC10684636 DOI: 10.1007/s00259-023-06418-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/24/2023] [Indexed: 09/09/2023]
Abstract
PURPOSE Image artefacts continue to pose challenges in clinical molecular imaging, resulting in misdiagnoses, additional radiation doses to patients and financial costs. Mismatch and halo artefacts occur frequently in gallium-68 (68Ga)-labelled compounds whole-body PET/CT imaging. Correcting for these artefacts is not straightforward and requires algorithmic developments, given that conventional techniques have failed to address them adequately. In the current study, we employed differential privacy-preserving federated transfer learning (FTL) to manage clinical data sharing and tackle privacy issues for building centre-specific models that detect and correct artefacts present in PET images. METHODS Altogether, 1413 patients with 68Ga prostate-specific membrane antigen (PSMA)/DOTA-TATE (TOC) PET/CT scans from 3 countries, including 8 different centres, were enrolled in this study. CT-based attenuation and scatter correction (CT-ASC) was used in all centres for quantitative PET reconstruction. Prior to model training, an experienced nuclear medicine physician reviewed all images to ensure the use of high-quality, artefact-free PET images (421 patients' images). A deep neural network (modified U2Net) was trained on 80% of the artefact-free PET images to utilize centre-based (CeBa), centralized (CeZe) and the proposed differential privacy FTL frameworks. Quantitative analysis was performed in 20% of the clean data (with no artefacts) in each centre. A panel of two nuclear medicine physicians conducted qualitative assessment of image quality, diagnostic confidence and image artefacts in 128 patients with artefacts (256 images for CT-ASC and FTL-ASC). RESULTS The three approaches investigated in this study for 68Ga-PET imaging (CeBa, CeZe and FTL) resulted in a mean absolute error (MAE) of 0.42 ± 0.21 (CI 95%: 0.38 to 0.47), 0.32 ± 0.23 (CI 95%: 0.27 to 0.37) and 0.28 ± 0.15 (CI 95%: 0.25 to 0.31), respectively. Statistical analysis using the Wilcoxon test revealed significant differences between the three approaches, with FTL outperforming CeBa and CeZe (p-value < 0.05) in the clean test set. The qualitative assessment demonstrated that FTL-ASC significantly improved image quality and diagnostic confidence and decreased image artefacts, compared to CT-ASC in 68Ga-PET imaging. In addition, mismatch and halo artefacts were successfully detected and disentangled in the chest, abdomen and pelvic regions in 68Ga-PET imaging. CONCLUSION The proposed approach benefits from using large datasets from multiple centres while preserving patient privacy. Qualitative assessment by nuclear medicine physicians showed that the proposed model correctly addressed two main challenging artefacts in 68Ga-PET imaging. This technique could be integrated in the clinic for 68Ga-PET imaging artefact detection and disentanglement using multicentric heterogeneous datasets.
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Affiliation(s)
- Isaac Shiri
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
- Department of Cardiology, Inselspital, University of Bern, Bern, Switzerland
| | - Yazdan Salimi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Mehdi Maghsudi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Elnaz Jenabi
- Research Center for Nuclear Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Sara Harsini
- BC Cancer Research Institute, Vancouver, BC, Canada
| | - Behrooz Razeghi
- Department of Computer Science, University of Geneva, Geneva, Switzerland
| | - Shayan Mostafaei
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
- Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden
| | - Ghasem Hajianfar
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Amirhossein Sanaat
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Esmail Jafari
- The Persian Gulf Nuclear Medicine Research Center, Department of Nuclear Medicine, Molecular Imaging, and Theranostics, Bushehr Medical University Hospital, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Rezvan Samimi
- Department of Medical Radiation Engineering, Shahid Beheshti University, Tehran, Iran
| | - Maziar Khateri
- Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Peyman Sheikhzadeh
- Department of Nuclear Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Parham Geramifar
- Research Center for Nuclear Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Habibollah Dadgar
- Cancer Research Center, Razavi Hospital, Imam Reza International University, Mashhad, Iran
| | - Ahmad Bitrafan Rajabi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
- Echocardiography Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Majid Assadi
- The Persian Gulf Nuclear Medicine Research Center, Department of Nuclear Medicine, Molecular Imaging, and Theranostics, Bushehr Medical University Hospital, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran
| | - François Bénard
- BC Cancer Research Institute, Vancouver, BC, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
| | - Alireza Vafaei Sadr
- Institute of Pathology, RWTH Aachen University Hospital, Aachen, Germany
- Department of Public Health Sciences, College of Medicine, The Pennsylvania State University, Hershey, PA, 17033, USA
| | | | - Ismini Mainta
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Carlos Uribe
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
- Molecular Imaging and Therapy, BC Cancer, Vancouver, BC, Canada
- Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, BC, Canada
| | - Arman Rahmim
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
- Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, BC, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland.
- Geneva University Neuro Center, Geneva University, Geneva, Switzerland.
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, Netherlands.
- Department of Nuclear Medicine, University of Southern Denmark, Odense, Denmark.
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Allen D, Jacob N, Strange H, Jones A, Burton C, Rafferty AM. "It's not just about the numbers": Inside the black box of nurses' professional judgement in nurse staffing systems in England and Wales: Insights from a qualitative cross-case comparative study. Int J Nurs Stud 2023; 147:104586. [PMID: 37672970 DOI: 10.1016/j.ijnurstu.2023.104586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 09/08/2023]
Abstract
BACKGROUND Whether implicit or explicit, professional judgement is a central component of the many nurse staffing systems implemented in high-income countries to inform workforce planning and staff deployment. Whilst a substantial body of research has evaluated the technical and operational elements of nurse staffing systems, no studies have systematically examined the role of professional judgement and its contribution to decision-making. OBJECTIVE To explore nurses' use of professional judgement in nurse staffing systems in England and Wales. METHODS A cross-case comparative design centred on adult in-patient services in three University Health Boards in Wales and three National Health Service Trusts in England. Data generation was undertaken between January 2021 and March 2023 through stakeholder interviews, observations of staffing meetings, and analysis of documents and artefacts. Observations were undertaken in clinical areas but limited to three cases by COVID-19 restrictions. Analysis was informed by translational mobilisation theory. FINDINGS Two kinds of professional judgement were deployed in the nurse staffing systems: the judgement of clinical nurses and the judgement of senior nurse managers. The research highlighted the reflexive relationship between professional judgement and data, and the circumstances in which organisations placed trust in people and when they placed trust in numbers. Nurses' professional judgement was central to the generation of data, its interpretation and contextualisation. Healthcare organisations relied on the professional judgements of clinical nurses and senior nurse managers in making operational decisions to mitigate risk, where real-world understanding of the status of the organisation was privileged over formal data. Professional judgement had attenuated authority for the purposes of workforce planning, where data was a master actor. Nurses expressed concerns that strategic decision-making prioritised safety and efficiency, and formal measurement systems did not capture important aspects of care quality or staff wellbeing, which made it difficult to articulate their professional judgement. CONCLUSIONS The implementation of staffing systems is resource intensive. Given limited evidence on which to recommend any specific methodology, the priority for future research is to optimise existing systems. If nurses are to deploy their professional judgement to proactively influence the conditions for care, as well as responding to the challenges of risk mitigation, there is a need for robust systems of nursing measurement aligned with agreed standards of care and a vocabulary through which these judgements can be articulated. TWEETABLE ABSTRACT Health systems depend on nurses' professional judgement for operational staffing decisions, but data is privileged over professional judgement for workforce planning.
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Affiliation(s)
- Davina Allen
- School of Healthcare Sciences, Cardiff University, Cardiff, UK.
| | - Nina Jacob
- Centre for Trials Research, Cardiff University, Cardiff, UK
| | | | - Aled Jones
- School of Healthcare Sciences, Cardiff University, Cardiff, UK
| | - Chris Burton
- School of Allied and Public Health Professions, Canterbury Christ Church University, Kent, UK
| | - Anne Marie Rafferty
- Florence Nightingale Faculty of Nursing, Midwifery and Palliative Care, King's College London, UK
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Socha M, Prażuch W, Suwalska A, Foszner P, Tobiasz J, Jaroszewicz J, Gruszczynska K, Sliwinska M, Nowak M, Gizycka B, Zapolska G, Popiela T, Przybylski G, Fiedor P, Pawlowska M, Flisiak R, Simon K, Walecki J, Cieszanowski A, Szurowska E, Marczyk M, Polanska J. Pathological changes or technical artefacts? The problem of the heterogenous databases in COVID-19 CXR image analysis. Comput Methods Programs Biomed 2023; 240:107684. [PMID: 37356354 PMCID: PMC10278898 DOI: 10.1016/j.cmpb.2023.107684] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 06/11/2023] [Accepted: 06/18/2023] [Indexed: 06/27/2023]
Abstract
BACKGROUND When the COVID-19 pandemic commenced in 2020, scientists assisted medical specialists with diagnostic algorithm development. One scientific research area related to COVID-19 diagnosis was medical imaging and its potential to support molecular tests. Unfortunately, several systems reported high accuracy in development but did not fare well in clinical application. The reason was poor generalization, a long-standing issue in AI development. Researchers found many causes of this issue and decided to refer to them as confounders, meaning a set of artefacts and methodological errors associated with the method. We aim to contribute to this steed by highlighting an undiscussed confounder related to image resolution. METHODS 20 216 chest X-ray images (CXR) from worldwide centres were analyzed. The CXRs were bijectively projected into the 2D domain by performing Uniform Manifold Approximation and Projection (UMAP) embedding on the radiomic features (rUMAP) or CNN-based neural features (nUMAP) from the pre-last layer of the pre-trained classification neural network. Additional 44 339 thorax CXRs were used for validation. The comprehensive analysis of the multimodality of the density distribution in rUMAP/nUMAP domains and its relation to the original image properties was used to identify the main confounders. RESULTS nUMAP revealed a hidden bias of neural networks towards the image resolution, which the regular up-sampling procedure cannot compensate for. The issue appears regardless of the network architecture and is not observed in a high-resolution dataset. The impact of the resolution heterogeneity can be partially diminished by applying advanced deep-learning-based super-resolution networks. CONCLUSIONS rUMAP and nUMAP are great tools for image homogeneity analysis and bias discovery, as demonstrated by applying them to COVID-19 image data. Nonetheless, nUMAP could be applied to any type of data for which a deep neural network could be constructed. Advanced image super-resolution solutions are needed to reduce the impact of the resolution diversity on the classification network decision.
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Affiliation(s)
- Marek Socha
- Department of Data Science and Engineering, Silesian University of Technology, Gliwice, Poland
| | - Wojciech Prażuch
- Department of Data Science and Engineering, Silesian University of Technology, Gliwice, Poland
| | - Aleksandra Suwalska
- Department of Data Science and Engineering, Silesian University of Technology, Gliwice, Poland
| | - Paweł Foszner
- Department of Data Science and Engineering, Silesian University of Technology, Gliwice, Poland; Department of Computer Graphics, Vision and Digital Systems, Silesian University of Technology, Gliwice, Poland
| | - Joanna Tobiasz
- Department of Data Science and Engineering, Silesian University of Technology, Gliwice, Poland; Department of Computer Graphics, Vision and Digital Systems, Silesian University of Technology, Gliwice, Poland
| | - Jerzy Jaroszewicz
- Department of Infectious Diseases and Hepatology, Medical University of Silesia, Katowice, Poland
| | - Katarzyna Gruszczynska
- Department of Radiology and Nuclear Medicine, Medical University of Silesia, Katowice, Poland
| | - Magdalena Sliwinska
- Department of Diagnostic Imaging, Voivodship Specialist Hospital, Wroclaw, Poland
| | - Mateusz Nowak
- Department of Radiology, Silesian Hospital, Cieszyn, Poland
| | - Barbara Gizycka
- Department of Imaging Diagnostics, MEGREZ Hospital, Tychy, Poland
| | | | - Tadeusz Popiela
- Department of Radiology, Jagiellonian University Medical College, Krakow, Poland
| | - Grzegorz Przybylski
- Department of Lung Diseases, Cancer and Tuberculosis, Kujawsko-Pomorskie Pulmonology Center, Bydgoszcz, Poland
| | - Piotr Fiedor
- Department of General and Transplantation Surgery, Medical University of Warsaw, Warsaw, Poland
| | - Malgorzata Pawlowska
- Department of Infectious Diseases and Hepatology, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Torun, Poland
| | - Robert Flisiak
- Department of Infectious Diseases and Hepatology, Medical University of Bialystok, Bialystok, Poland
| | - Krzysztof Simon
- Department of Infectious Diseases and Hepatology, Wroclaw Medical University, Wroclaw, Poland
| | - Jerzy Walecki
- Department of Radiology, Centre of Postgraduate Medical Education, Central Clinical Hospital of the Ministry of Interior in Warsaw, Poland
| | - Andrzej Cieszanowski
- Department of Radiology I, The Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Edyta Szurowska
- 2nd Department of Radiology, Medical University of Gdansk, Poland
| | - Michal Marczyk
- Department of Data Science and Engineering, Silesian University of Technology, Gliwice, Poland; Yale Cancer Center, Yale School of Medicine, New Haven, CT, USA
| | - Joanna Polanska
- Department of Data Science and Engineering, Silesian University of Technology, Gliwice, Poland.
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Cascante-Sequeira D, Fontenele RC, Martins LAC, Brasil DM, Oliveira ML, Freitas DQ, Haiter-Neto F. Does the shape of the field-of-view influence the magnitude of artefacts from high-density materials in cone-beam computed tomography? Dentomaxillofac Radiol 2023; 52:20230147. [PMID: 37493606 PMCID: PMC10552126 DOI: 10.1259/dmfr.20230147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 07/27/2023] Open
Abstract
OBJECTIVE To compare cylindrical and convex triangular field-of-views (FOVs) concerning the magnitude of artefacts from high-density materials in cone-beam CT (CBCT). METHODS AND MATERIALS Cylinders of amalgam, chromium-cobalt, titanium, and zirconia were individually placed in the anterior and posterior regions of a polymethylmethacrylate phantom and scanned using cylindrical and convex triangular FOVs of the Veraview X800 CBCT device. Using the Image J software, 15 square regions of interest (ROIs) were placed in the axial reconstruction around the middle level of the cylinder and at distances of 0.5, 1.0, and 1.5 cm from the centre of the cylinder. Mean grey value and standard deviation of each ROI were averaged for each distance and subtracted from the values of a control ROI to calculate the magnitude of the artefacts by the grey value mean difference (GVMD) and grey value standard deviation (GVSD). Multiway analysis of variance with Tukey post-hoc test with a significance level of 5% evaluated the effect of the shape of the FOV, position inside the FOV, high-density material, and the distance of the artefact from the material. RESULTS The convex triangular FOV increased the GVSD for all materials in the anterior and posterior regions at 0.5 cm compared to the cylindrical FOV (p < 0.0001). The convex triangular FOV showed greater GVMD for chromium-cobalt and zirconium in the anterior region and all materials in the posterior region at all distances (p < 0.0001). CONCLUSION The FOV shape influences the magnitude of artefacts from high-density materials. The convex triangular FOV showed greater artefact magnitude with variability among the high-density materials, region in the FOV, and distance from the material.
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Affiliation(s)
- Deivi Cascante-Sequeira
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | | | - Luciano Augusto Cano Martins
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Danieli Moura Brasil
- Department of Oral Diagnosis & Oral Health, University of Louisville School of Dentistry, Louisville, United States of America
| | - Matheus L Oliveira
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Deborah Queiroz Freitas
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Francisco Haiter-Neto
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
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Vuorinen AM, Lehmonen L, Karvonen J, Holmström M, Kivistö S, Kaasalainen T. Reducing cardiac implantable electronic device-induced artefacts in cardiac magnetic resonance imaging. Eur Radiol 2023; 33:1229-1242. [PMID: 36029346 PMCID: PMC9889467 DOI: 10.1007/s00330-022-09059-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 06/17/2022] [Accepted: 07/24/2022] [Indexed: 02/04/2023]
Abstract
OBJECTIVES Cardiac implantable electronic device (CIED)-induced metal artefacts possibly significantly diminish the diagnostic value of magnetic resonance imaging (MRI), particularly cardiac MR (CMR). Right-sided generator implantation, wideband late-gadolinium enhancement (LGE) technique and raising the ipsilateral arm to the generator during CMR scanning may reduce the CIED-induced image artefacts. We assessed the impact of generator location and the arm-raised imaging position on the CIED-induced artefacts in CMR. METHODS We included all clinically indicated CMRs performed on patients with normal cardiac anatomy and a permanent CIED with endocardial pacing leads between November 2011 and October 2019 in our institution (n = 171). We analysed cine and LGE sequences using the American Heart Association 17-segment model for the presence of artefacts. RESULTS Right-sided generator implantation and arm-raised imaging associated with a significantly increased number of artefact-free segments. In patients with a right-sided pacemaker, the median percentage of artefact-free segments in short-axis balanced steady-state free precession LGE was 93.8% (IQR 9.4%, n = 53) compared with 78.1% (IQR 20.3%, n = 58) for left-sided pacemaker (p < 0.001). In patients with a left-sided implantable cardioverter-defibrillator, the median percentage of artefact-free segments reached 87.5% (IQR 6.3%, n = 9) using arm-raised imaging, which fell to 62.5% (IQR 34.4%, n = 9) using arm-down imaging in spoiled gradient echo short-axis cine (p = 0.02). CONCLUSIONS Arm-raised imaging represents a straightforward method to reduce CMR artefacts in patients with left-sided generators and can be used alongside other image quality improvement methods. Right-sided generator implantation could be considered in CIED patients requiring subsequent CMR imaging to ensure sufficient image quality. KEY POINTS • Cardiac implantable electronic device (CIED)-induced metal artefacts may significantly diminish the diagnostic value of an MRI, particularly in cardiac MRIs. • Raising the ipsilateral arm relative to the CIED generator is a cost-free, straightforward method to significantly reduce CIED-induced artefacts on cardiac MRIs in patients with a left-sided generator. • Right-sided generator implantation reduces artefacts compared with left-sided implantation and could be considered in CIED patients requiring subsequent cardiac MRIs to ensure adequate image quality in the future.
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Affiliation(s)
- Aino-Maija Vuorinen
- Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
| | - Lauri Lehmonen
- Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
| | - Jarkko Karvonen
- Heart and Lung Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
| | - Miia Holmström
- Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
| | - Sari Kivistö
- Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
| | - Touko Kaasalainen
- Radiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, P.O. Box 340, HUS, 00029 Helsinki, Finland
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10
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Stein P, Lückerath C, Melzig C, Bülhoff M, Tanner M, Kauczor HU, Rehnitz C. [Postoperative imaging of the shoulder]. Radiologie (Heidelb) 2022; 62:835-843. [PMID: 35771235 DOI: 10.1007/s00117-022-01026-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Imaging of the postoperative shoulder joint includes complex, diagnostically challenging changes regarding the anatomical structures. OBJECTIVES Case-based presentation of common surgical procedures, expected postoperative findings, and typical complications. MATERIALS AND METHODS Interdisciplinary evaluation of (didactically instructive) cases and discussion of pertinent literature and expert opinions. RESULTS Presentation of normal postoperative findings and complications after subacromial decompression, surgical treatment of rotator cuff lesions, SLAP (superior labral anterior to posterior) lesions/lesions of the long biceps tendon, Bankart lesions as well as instability-related procedures and after shoulder arthroplasty. Discussion of the appropriate use of imaging methods with a focus on magnetic resonance imaging (MRI), which are supplemented by computed tomography (CT), and conventional x‑ray images. CONCLUSION The broad spectrum of complex findings as well as the evermore developing and thereby changing surgical procedures result in significant challenges in the radiological evaluation of the postoperative shoulder joint. To differentiate physiological reactions from pathological changes it is necessary to have general knowledge of the common surgical procedures, expected postoperative findings and possible complications. A variety imaging modalities can be used to further advance diagnostic precision.
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Affiliation(s)
- P Stein
- Diagnostische und Interventionelle Radiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Deutschland
| | - C Lückerath
- Diagnostische und Interventionelle Radiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Deutschland
| | - C Melzig
- Diagnostische und Interventionelle Radiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Deutschland
| | - M Bülhoff
- Klinik für Orthopädie und Unfallchirurgie, Universitätsklinikum Heidelberg, Heidelberg, Deutschland
| | - M Tanner
- Klinik für Orthopädie und Unfallchirurgie, Universitätsklinikum Heidelberg, Heidelberg, Deutschland
| | - H U Kauczor
- Diagnostische und Interventionelle Radiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Deutschland
| | - C Rehnitz
- Diagnostische und Interventionelle Radiologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Deutschland.
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11
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Tsikas D, Mikuteit M. N-Acetyl-L-cysteine in human rheumatoid arthritis and its effects on nitric oxide (NO) and malondialdehyde (MDA): analytical and clinical considerations. Amino Acids 2022; 54:1251-1260. [PMID: 35829920 PMCID: PMC9372125 DOI: 10.1007/s00726-022-03185-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/27/2022] [Indexed: 12/21/2022]
Abstract
N-Acetyl-L-cysteine (NAC) is an endogenous cysteine metabolite. The drug is widely used in chronic obstructive pulmonary disease (COPD) and as antidote in acetaminophen (paracetamol) intoxication. Currently, the utility of NAC is investigated in rheumatoid arthritis (RA), which is generally considered associated with inflammation and oxidative stress. Besides clinical laboratory parameters, the effects of NAC are evaluated by measuring in plasma or serum nitrite, nitrate or their sum (NOx) as measures of nitric oxide (NO) synthesis. Malondialdehyde (MDA) and relatives such as 4-hydroxy-nonenal and 15(S)-8-iso-prostaglandin F2α serve as measures of oxidative stress, notably lipid peroxidation. In this work, we review recent clinico-pharmacological studies on NAC in rheumatoid arthritis. We discuss analytical, pre-analytical and clinical issues and their potential impact on the studies outcome. Major issues include analytical inaccuracy due to interfering endogenous substances and artefactual formation of MDA and relatives during storage in long-term studies. Differences in the placebo and NAC groups at baseline with respect to these biomarkers are also a serious concern. Modern applied sciences are based on data generated using commercially available instrumental physico-chemical and immunological technologies and assays. The publication process of scientific work rarely undergoes rigorous peer review of the analytical approaches used in the study in terms of accuracy/trueness. There is pressing need of considering previously reported reference concentration ranges and intervals as well as specific critical issues such as artefactual formation of particular biomarkers during sample storage. The latter especially applies to surrogate biomarkers of oxidative stress, notably MDA and relatives. Reported data on NO, MDA and clinical parameters, including C-reactive protein, interleukins and tumour necrosis factor α, are contradictory in the literature. Furthermore, reported studies do not allow any valid conclusion about utility of NAC in RA. Administration of NAC patients with rheumatoid arthritis is not recommended in current European and American guidelines.
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Affiliation(s)
- Dimitrios Tsikas
- Core Unit Proteomics, Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Marie Mikuteit
- Clinic for Rheumatology und Immunology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
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12
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Lan Y, Huang X, Fan M, Yu H, Xie Z, Zhou Y. Accuracy evaluation of cone beam computed tomography applied to measure peri-implant bone thickness in living patients: an ex vivo and in vivo experiment. Clin Oral Investig 2022; 26:6347-6359. [PMID: 35802190 DOI: 10.1007/s00784-022-04590-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/19/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVES This study aims to study the accuracy of cone beam computed tomography (CBCT) for measuring peri-implant bone thickness in living patients via a novel visualization method (NVM). MATERIAL AND METHODS The validity of the NVM was verified ex vivo by measuring the same peri-implant bone thicknesses in bovine ribs by using raw postoperative CBCT (clinical measurement, CM), the visualized fused images obtained using the NVM (visualized fused measurement, VF), and hard tissue sections (gold standard measurement, GS). The NVM was applied by deconstructing the postoperative CBCT model into the Modelpost-bone and Modelimplant and replacing it with bone from preoperative CBCT and standard implant models, respectively. In vivo, 52 implants were included, and the VF of each implant was obtained using data processing methods similar to those used ex vivo. Then, we compared the results of CM and VF. RESULTS Ex vivo, the VF was similar to GS, while CM usually underestimated the peri-implant bone thickness, especially at the implant shoulder (P < 0.01). In vivo, on CBCT, areas with a peri-implant bone thickness of 0-0.50 mm were not visible, while those with a thickness of 0.50-1.00 mm were occasionally visible. There was less underestimation of bone along the implant long axis. CONCLUSIONS Thin peri-implant bones could be completely underestimated on CBCT. CBCT scans alone are insufficient to warrant surgical intervention. Our NVM facilitates the accurate visual assessment of implant dimensions. CLINICAL RELEVANCE The thickness of peri-implant bone could be completely underestimated when thinner than 1.0 mm in living patients. Familiarity with these confusing CBCT results may help clinicians and patients avoid further unnecessary evaluation, misdiagnosis, and invasive treatment.
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Affiliation(s)
- Yanhua Lan
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China
| | - Xiaoyuan Huang
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China
| | - Mingxing Fan
- Hangzhou 6D Dental Technologies Co., Ltd, Hangzhou, 310001, People's Republic of China
| | - Huazhen Yu
- School of Mathematical Sciences, Zhejiang University, Hangzhou, 310012, People's Republic of China
| | - Zhijian Xie
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China.
| | - Yiqun Zhou
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China.
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Falek S, Regmi R, Herault J, Dore M, Vela A, Dutheil P, Moignier C, Marcy PY, Drouet J, Beddok A, Letwin NE, Epstein J, Parvathaneni U, Thariat J. Dental management in head and neck cancers: from intensity-modulated radiotherapy with photons to proton therapy. Support Care Cancer 2022; 30:8377-8389. [PMID: 35513755 DOI: 10.1007/s00520-022-07076-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 04/18/2022] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Despite reduction of xerostomia with intensity-modulated compared to conformal X-ray radiotherapy, radiation-induced dental complications continue to occur. Proton therapy is promising in head and neck cancers to further reduce radiation-induced side-effects, but the optimal dental management has not been defined. MATERIAL AND METHODS Dental management before proton therapy was assessed compared to intensity-modulated radiotherapy based on a bicentric experience, a literature review and illustrative cases. RESULTS Preserved teeth frequently contain metallic dental restorations (amalgams, crowns, implants). Metals blur CT images, introducing errors in tumour and organ contour during radiotherapy planning. Due to their physical interactions with matter, protons are more sensitive than photons to tissue composition. The composition of restorative materials is rarely documented during radiotherapy planning, introducing dose errors. Manual artefact recontouring, metal artefact-reduction CT algorithms, dual or multi-energy CT and appropriate dose calculation algorithms insufficiently compensate for contour and dose errors during proton therapy. Physical uncertainties may be associated with lower tumour control probability and more side-effects after proton therapy. Metal-induced errors should be quantified and removal of metal restorations discussed on a case by case basis between dental care specialists, radiation oncologists and physicists. Metallic amalgams can be replaced with water-equivalent materials and crowns temporarily removed depending on rehabilitation potential, dental condition and cost. Implants might contraindicate proton therapy if they are in the proton beam path. CONCLUSION Metallic restorations may more severely affect proton than photon radiotherapy quality. Personalized dental care prior to proton therapy requires multidisciplinary assessment of metal-induced errors before choice of conservation/removal of dental metals and optimal radiotherapy.
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Affiliation(s)
- Sabah Falek
- Department of Oral and Maxillo-Facial Surgery, Francois Baclesse Center, Caen, France
| | - Rajesh Regmi
- Seattle Cancer Care Alliance Proton Therapy Center, Seattle, WA, USA
| | - Joel Herault
- Institut Méditerranéen de Protonthérapie, Antoine Lacassagne Center, Nice, France
| | - Melanie Dore
- Department of Radiation Oncology, Institut de Cancérologie de L'Ouest, Nantes, France
| | - Anthony Vela
- Department of Medical Physics, François Baclesse Center / Proton Therapy Center, Caen, France
| | - Pauline Dutheil
- Department of Medical Physics, François Baclesse Center / Proton Therapy Center, Caen, France
| | - Cyril Moignier
- Department of Medical Physics, François Baclesse Center / Proton Therapy Center, Caen, France
| | - Pierre-Yves Marcy
- Radiodiagnostics and Interventional Radiology, Polyclinique ELSAN, Ollioules, France
| | - Julien Drouet
- Department of Oral and Maxillo-Facial Surgery, Francois Baclesse Center, Caen, France
| | - Arnaud Beddok
- Department of Radiation Oncology, Curie Institute, Paris, France
| | - Noah E Letwin
- Swedish Medical Center General Practice Residency, Seattle, WA and owner Seattle Special Care Dentistry, Seattle, WA, USA
| | - Joel Epstein
- City of Hope Comprehensive Cancer Center, Duarte CA and Cedars-Sinai Medical System, Los Angeles, CA, USA
| | - Upendra Parvathaneni
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, USA
| | - Juliette Thariat
- Department of Radiation Oncology, Centre François Baclesse, Caen, France.
- Laboratoire de Physique Corpusculaire, IN2P3/ENISAEN-CNRS, Caen, France.
- Normandie Universite, Caen, France.
- SAS Cyclhad, Hérouville-Saint-Clair, France.
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Wanderley VA, Leite AF, de Faria Vasconcelos K, Pauwels R, Müller-García F, Becker K, Oliveira ML, Jacobs R. Impact of metal artefacts on subjective perception of image quality of 13 CBCT devices. Clin Oral Investig 2022; 26:4457-4466. [PMID: 35166942 DOI: 10.1007/s00784-022-04409-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 02/09/2022] [Indexed: 12/01/2022]
Abstract
OBJECTIVES The overall objective of this study was to assess how metal artefacts impact image quality of 13 CBCT devices. As a secondary objective, the influence of scanning protocols and field of view on CBCT image quality with and without metal artefacts was also assessed. MATERIALS AND METHODS CBCT images were acquired of a dry human skull phantom considering three clinical simulated conditions: one without metal and two with metallic materials (metallic pin and implant). An industrial micro-CT was used as a reference to register the CBCT images. Afterwards, four observers evaluated 306 representative image slices from 13 devices, ranking them from best to worst. Furthermore, within each device, medium FOV and small FOV standard images were compared. General linear mixed models were used to assess subjective perception of examiners on overall image quality in the absence and presence of metal-related artefacts (p < 0.05). RESULTS Image quality perception significantly differed amongst CBCT devices (p < 0.05). Some devices performed significantly better, independently of scanning protocol and clinical condition. In the presence of metal artefacts, medium FOV standard scanning protocols scored significantly better, while in the absence of metal, small FOV standard yielded the highest performance. CONCLUSIONS Subjective image quality differs significantly amongst CBCT devices and scanning protocols. Metal-related artefacts may highly impact image quality, with a significant device-dependent variability and only few scanners being more robust against metal artefacts. Often, metal artefact expression may be somewhat reduced by proper protocol selection. CLINICAL RELEVANCE Metallic objects may severely impact image quality in several CBCT devices.
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Affiliation(s)
- Victor Aquino Wanderley
- OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium. .,Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil.
| | - Andre Ferreira Leite
- OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium.,Department of Dentistry, Faculty of Health Sciences, University of Brasília, Brasília, Brazil
| | - Karla de Faria Vasconcelos
- OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Ruben Pauwels
- Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark.,Department of Mechanical Engineering, Catholic University of Leuven, Leuven, Belgium
| | - Francisca Müller-García
- OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Kathrin Becker
- Department of Orthodontics, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Matheus L Oliveira
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil
| | - Reinhilde Jacobs
- OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium.,Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden
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15
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Bolat Gümüş E, Şatir S, Kuştarci A. Microleakage beneath orthodontic brackets in high field magnetic resonance imaging (MRI) AT 1.5 & 3 tesla. Dentomaxillofac Radiol 2022; 51:20210512. [PMID: 35113678 PMCID: PMC9499206 DOI: 10.1259/dmfr.20210512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The aim of the present study was to evaluate the effects of 1.5 T and 3 T MRI on the adhesion between the orthodontic brackets and the teeth by evaluating the microleakage between theenamel, adhesive and brackets interfaces. METHODS Fifty-eight extracted human premolars which were received a standard bracket bonding procedure were randomly divided into three groups; control group (n = 20; no MRI), 1.5 T MRI group (n = 19; 20 min MRI exposure of 1.5 T) and 3 T MRI group (n = 19; 20 min MRI exposure of 3 T). The teeth were kept in distiled water for 2 weeks, and thereafter subjected to 500 thermal cycles. Then specimens were sealed with nail varnish, stained with 0.5% basic fuchsin for 24 h, sectioned and photographed under a stereomicroscope. Microleakage was scored with regard to the adhesive-enamel and bracket-adhesive interfaces at the occlusal and gingival levels. Statistical analysis was accomplished by Kruskal-Wallis and Bonferroni-Dunn tests. RESULTS All of the groups exhibited statistically similar microleakage scores in the adhesive-enamel interface along occlusal margins (p>0.05, p = 0.331). The mean microleakage scores along gingival margins in the 3 T MRI group was significantly higher compared to the control group both in the adhesiv-enamel and bracket-adhesive interfaces (p<0.05, p = 0.019 and p = 0.020 respectively). The microleakage scores along the gingival margins were also significantly higher than the occlusal margins in the 3 T MRI group (p<0.05, p = 0.029). CONCLUSIONS 3 T MRI may weaken the adhesion between the enamel and the stainless steel orthodontic brackets.
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Affiliation(s)
- Esra Bolat Gümüş
- Orthodontics Department, Faculty of Dentistry, Akdeniz University, Antalya, Turkey
| | - Samed Şatir
- Oral and Maxillofacial Radiology Department, Faculty of Dentistry, Alanya Alaaddin Keykubat University, Antalya, Turkey
| | - Alper Kuştarci
- Endodontics Department, Faculty of Dentistry, Akdeniz University, Antalya, Turkey
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16
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Demirturk Kocasarac H, Koenig LJ, Ustaoglu G, Oliveira ML, Freitas DQ. CBCT image artefacts generated by implants located inside the field of view or in the exomass. Dentomaxillofac Radiol 2022; 51:20210092. [PMID: 34289314 PMCID: PMC8802698 DOI: 10.1259/dmfr.20210092] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
OBJECTIVES To compare artefacts in cone-beam computed tomography (CBCT) arising from implants of different materials located either inside the field of view (FOV) or in the exomass, and to test different image-acquisition parameters to reduce them. METHODS CBCT scans of a human mandible prepared with either a titanium, titanium-zirconium, or zirconia implant were acquired with the Planmeca ProMax utilizing FOV sizes of 8 × 5 cm and 4 × 5 cm, which placed the implant inside the FOV (8 × 5 cm) or in the exomass (4 × 5 cm). The scanning parameters considered three conditions of metal artefact reduction (MAR), disabled, low, and high, and 2 kVp levels (80 and 90). The standard deviation (SD) of grey values of regions of interest was obtained. The effects of implant material, implant position, MAR condition, kVp level, and their interactions were evaluated by Analysis of Variance (α = 5%). RESULTS The zirconia implant produced the highest SD values (more heterogeneous grey values, corresponding to greater artefact expression), followed by titanium-zirconium, and titanium. In general, implants in the exomass produced images with higher SD values than implants inside the FOV. MAR was effective in decreasing SD values, especially from the zirconia implant, only when the implant was inside the FOV. Images with 80 kVp had higher SD values than those with 90 kVp, regardless of the other factors (p < 0.05). CONCLUSIONS Implants in the exomass lead to greater artefact expression than when they are inside the FOV. Special attention should be paid to scanning parameters that reduce metal-related artefacts, such as MAR activation and increasing kVp. This is especially important with a zirconia implant inside the FOV.
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Affiliation(s)
- Husniye Demirturk Kocasarac
- Division of Oral and Maxillofacial Radiology, Department of General Dental Sciences, Marquette University School of Dentistry, Milwaukee, Wisconsin, United States
| | - Lisa J Koenig
- Division of Oral and Maxillofacial Radiology, Department of General Dental Sciences, Marquette University School of Dentistry, Milwaukee, Wisconsin, United States
| | - Gulbahar Ustaoglu
- Department of Periodontics, Bolu Abant Izzet Baysal University Faculty of Dentistry, BAIBU Golkoy Yerleskesi, Merkez/Bolu, Turkey
| | - Matheus Lima Oliveira
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Deborah Queiroz Freitas
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
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17
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Christenhusz A, Pouw JJ, Simonis FFJ, Douek M, Ahmed M, Klaase JM, Dassen AE, Klazen CAH, van der Schaaf MC, Ten Haken B, Alic L. Breast MRI in patients after breast conserving surgery with sentinel node procedure using a superparamagnetic tracer. Eur Radiol Exp 2022; 6:3. [PMID: 35083595 PMCID: PMC8792114 DOI: 10.1186/s41747-021-00257-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 12/03/2021] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND A procedure for sentinel lymph node biopsy (SLNB) using superparamagnetic iron-oxide (SPIO) nanoparticles and intraoperative sentinel lymph node (SLN) detection was developed to overcome drawbacks associated with the current standard-of-care SLNB. However, residual SPIO nanoparticles can result in void artefacts at follow-up magnetic resonance imaging (MRI) scans. We present a grading protocol to quantitatively assess the severity of these artefacts and offer an option to minimise the impact of SPIO nanoparticles on diagnostic imaging. METHODS Follow-up mammography and MRI of two patient groups after a magnetic SLNB were included in the study. They received a 2-mL subareolar dose of SPIO (high-dose, HD) or a 0.1-mL intratumoural dose of SPIO (low-dose, LD). Follow-up mammography and MRI after magnetic SLNB were acquired within 4 years after breast conserving surgery (BCS). Two radiologists with over 10-year experience in breast imaging assessed the images and analysed the void artefacts and their impact on diagnostic follow-up. RESULTS A total of 19 patients were included (HD, n = 13; LD, n = 6). In the HD group, 9/13 patients displayed an artefact on T1-weighted images up to 3.6 years after the procedure, while no impact of the SPIO remnants was observed in the LD group. CONCLUSIONS SLNB using a 2-mL subareolar dose of magnetic tracer in patients undergoing BCS resulted in residual artefacts in the breast in the majority of patients, which may hamper follow-up MRI. This can be avoided by using a 0.1-mL intratumoural dose.
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Affiliation(s)
- Anke Christenhusz
- Magnetic Detection & Imaging group, Technical Medical Centre, University of Twente, Enschede, The Netherlands.
- Department of Surgery Medisch Spectrum Twente, Enschede, The Netherlands.
| | - Joost J Pouw
- Magnetic Detection & Imaging group, Technical Medical Centre, University of Twente, Enschede, The Netherlands
| | - Frank F J Simonis
- Magnetic Detection & Imaging group, Technical Medical Centre, University of Twente, Enschede, The Netherlands
| | - Michael Douek
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
| | - Muneer Ahmed
- Division of Surgery and Interventional Science, University College London, Royal Free Hospital, London, UK
| | - Joost M Klaase
- Department of Surgery Medisch Spectrum Twente, Enschede, The Netherlands
| | - Anneriet E Dassen
- Department of Surgery Medisch Spectrum Twente, Enschede, The Netherlands
| | | | | | - Bernard Ten Haken
- Magnetic Detection & Imaging group, Technical Medical Centre, University of Twente, Enschede, The Netherlands
| | - Lejla Alic
- Magnetic Detection & Imaging group, Technical Medical Centre, University of Twente, Enschede, The Netherlands
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18
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Pamukcu U, Tetik H, Peker I, Karadag Atas O, Zafersoy Akarslan Z. Effect of enveloping and disinfection methods on artefact formation on enveloped PSP plate images. Oral Radiol 2022; 38:558-564. [PMID: 35064886 PMCID: PMC8783187 DOI: 10.1007/s11282-022-00587-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 01/09/2022] [Indexed: 12/23/2022]
Abstract
Objectives To investigate the artefacts caused by different disinfection and protection methods that can be used for infection control of photostimulable phosphor (PSP) plates. Methods The plates that were enveloped with single or double envelopes were sprayed with an alcohol-containing solution or wiped with an alcohol-containing tissue. Four PSP groups with two plates in each group were formed (A = wiping single envelope, B = wiping double envelopes, C = spraying onto single envelope, and D = spraying onto double envelopes). Any artefacts (1 = no artefact, 2 = presence of artefact less than 0.5 cm wide, and 3 = presence of artefact larger than 0.5 cm wide) on the 12 acquired images were evaluated. Results Artefacts (score-3) occurred on the images of Group C-2 PSP plate after the 3rd exposure. According to the Kruskal–Wallis test the difference between the artefact score of the four methods was found significant. Post-hoc comparisons showed the Group C artefact scores were higher than the others and the difference was significant. The total time of enveloping and disinfection processes for groups was; A = 6.30 min, B = 7.58 min, C = 5.48 min, and D = 7.14 min. Conclusions Regardless of the number of envelopes, wiping with a tissue was less likely to cause artefacts, while spraying was reliable only when double envelopes were used. However, using a tissue and double envelopes, which are less risky in terms of artefact, causes time loss, difficulty in manipulation, environmental pollution and high cost.
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Affiliation(s)
- Umut Pamukcu
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Gazi University, 2. Sokak No: 4 Emek, Ankara, Turkey.
| | - Hatice Tetik
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Gazi University, 2. Sokak No: 4 Emek, Ankara, Turkey
| | - Ilkay Peker
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Gazi University, 2. Sokak No: 4 Emek, Ankara, Turkey
| | - Ozge Karadag Atas
- Department of Statistics, Faculty of Sciences, Hacettepe University, Ankara, Turkey
| | - Zuhre Zafersoy Akarslan
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Gazi University, 2. Sokak No: 4 Emek, Ankara, Turkey
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19
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Fabietti M, Mahmud M, Lotfi A. Channel-independent recreation of artefactual signals in chronically recorded local field potentials using machine learning. Brain Inform 2022; 9:1. [PMID: 34997378 PMCID: PMC8741911 DOI: 10.1186/s40708-021-00149-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/23/2021] [Indexed: 11/13/2022] Open
Abstract
Acquisition of neuronal signals involves a wide range of devices with specific electrical properties. Combined with other physiological sources within the body, the signals sensed by the devices are often distorted. Sometimes these distortions are visually identifiable, other times, they overlay with the signal characteristics making them very difficult to detect. To remove these distortions, the recordings are visually inspected and manually processed. However, this manual annotation process is time-consuming and automatic computational methods are needed to identify and remove these artefacts. Most of the existing artefact removal approaches rely on additional information from other recorded channels and fail when global artefacts are present or the affected channels constitute the majority of the recording system. Addressing this issue, this paper reports a novel channel-independent machine learning model to accurately identify and replace the artefactual segments present in the signals. Discarding these artifactual segments by the existing approaches causes discontinuities in the reproduced signals which may introduce errors in subsequent analyses. To avoid this, the proposed method predicts multiple values of the artefactual region using long–short term memory network to recreate the temporal and spectral properties of the recorded signal. The method has been tested on two open-access data sets and incorporated into the open-access SANTIA (SigMate Advanced: a Novel Tool for Identification of Artefacts in Neuronal Signals) toolbox for community use.
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Affiliation(s)
- Marcos Fabietti
- Department of Computer Science, Nottingham Trent University, Clifton Lane, NG11 8NS, Nottingham, UK
| | - Mufti Mahmud
- Department of Computer Science, Nottingham Trent University, Clifton Lane, NG11 8NS, Nottingham, UK. .,Medical Technologies Innovation Facility, Nottingham Trent University, Clifton Lane, NG11 8NS, Nottingham, UK. .,Computing and Informatics Research Centre, Nottingham Trent University, Clifton Lane, NG11 8NS, Nottingham, UK.
| | - Ahmad Lotfi
- Department of Computer Science, Nottingham Trent University, Clifton Lane, NG11 8NS, Nottingham, UK
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20
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Abstract
According to some philosophers of technology, technology embodies moral values in virtue of its functional properties and the intentions of its designers. But this paper shows that such an account makes the values supposedly embedded in technology epistemically opaque and that it does not allow for values to change. Therefore, to overcome these shortcomings, the paper introduces the novel Affordance Account of Value Embedding as a superior alternative. Accordingly, artefacts bear affordances, that is, artefacts make certain actions likelier given the circumstances. Based on an interdisciplinary perspective that invokes recent moral anthropology, I conceptualize affordances as response-dependent properties. That is, they depend on intrinsic as well as extrinsic properties of the artefact. We have reason to value these properties. Therefore, artefacts embody values and are not value-neutral, which has practical implications for the design of new technologies.
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Affiliation(s)
- Michael Klenk
- Delft University of Technology, 2628BX Delft, The Netherlands
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21
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Wanderley VA, de Faria Vasconcelos K, Leite AF, Pauwels R, Shujaat S, Jacobs R, Oliveira ML. Impact of the blooming artefact on dental implant dimensions in 13 cone-beam computed tomography devices. Int J Implant Dent 2021; 7:67. [PMID: 34258634 PMCID: PMC8277908 DOI: 10.1186/s40729-021-00347-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 04/22/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The purpose of this study was to objectively assess dimensional alteration (blooming artefact) on dental implant using 13 cone-beam computed tomography (CBCT) devices adjusted to device-specific scanning protocols and to assess whether subjective adjustment of brightness and contrast (B&C) could alter its visualization. METHODS An anthropomorphic phantom containing a dental implant was scanned in 13 CBCT devices adjusted to three scanning protocols: medium-FOV standard resolution, small-FOV standard resolution, and small-FOV high resolution. The diameter of the implant was measured at five levels, averaged, and compared with those from a reference standard industrial CT image. B&C adjustments were performed and measurements were repeated. The intraclass correlation coefficient assessed the reliability of the measurements and general linear mixed models were applied for multiples comparisons at a 95% confidence interval. RESULTS Implant diameter obtained from small-FOV high-resolution protocols in most CBCT devices was not significantly different when compared to that from the reference (p > 0.05). For standard protocols, significant dimensional alteration of the implant ranging from 23 to 34% (0.67 to 1.02 mm) was observed in 9 CBCT devices for small-FOV scanning (p < 0.05), and in 8 CBCT devices for medium-FOV scanning, implant dimensional alteration ranged significantly from 21 to 35% (0.62 to 1.04 mm). After B&C adjustments, dimensional alteration was reduced for several of the CBCT devices tested (p < 0.05). CONCLUSIONS The visualization of the implant dimensional alteration differed between CBCT devices and scanning protocols with an increase in diameter ranging from 0.27 to 1.04 mm. For most CBCT devices, B&C adjustments allowed to reduce visualization of implant blooming.
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Affiliation(s)
- Victor Aquino Wanderley
- OMFS-IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium. .,Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
| | - Karla de Faria Vasconcelos
- OMFS-IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Andre Ferreira Leite
- OMFS-IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium.,Department of Dentistry, Faculty of Health Sciences University of Brasília, Brasília, Brazil
| | - Ruben Pauwels
- Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark.,Department of Mechanical Engineering, Catholic University of Leuven, Leuven, Belgium
| | - Sohaib Shujaat
- OMFS-IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Reinhilde Jacobs
- OMFS-IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium.,Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Matheus L Oliveira
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
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22
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Neppalli S, Kessell MA, Madeley CR, Hill ML, Vlaskovsky PS, Taylor DB. Artifacts in contrast-enhanced mammography: are there differences between vendors? Clin Imaging 2021; 80:123-130. [PMID: 34311215 DOI: 10.1016/j.clinimag.2021.06.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 06/07/2021] [Accepted: 06/17/2021] [Indexed: 12/12/2022]
Abstract
PURPOSE Contrast-Enhanced Mammography (CEM) produces a dual-energy subtracted (DES) image that demonstrates iodine uptake (neovascularity) in breast tissue. We aim to review a range of artifacts on DES images produced using equipment from two different vendors and compare their incidence and subjective severity. METHODS We retrospectively reviewed CEM studies performed between September 2013 and March 2017 using GE Senographe Essential (n = 100) and Hologic Selenia Dimensions (n = 100) equipment. Artifacts were categorized and graded in severity by a subspecialist breast radiologist and one of two medical imaging technologists in consensus. The incidence of artifacts between vendors was compared by calculating the relative risk, and the severity gradings were compared using a Wilcoxon rank-sum test. RESULTS Elephant rind, corrugations and the black line on chest wall artifact were seen exclusively in Hologic images. Artifacts such as cloudy fat, negative rim around lesion and white line on pectoral muscle were seen in significantly more Hologic images (p < 0.05) whilst halo, ripple, skin line enhancement, black line on pectoral muscle, bright pectorals, chest wall high-lighting and air gap were seen in significantly more GE images (p < 0.05). The severity gradings for cloudy fat had a significantly higher mean rank in Hologic images (p < 0.001) whilst halo and ripple artifacts had a significantly higher mean rank in GE images (p < 0.001 and p = 0.028 respectively). CONCLUSION The type, incidence and subjective severity of CEM-specific artifacts differ between vendors. Further research is needed, but differences in algorithms used to produce the DE image are postulated to be a significant contributor.
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Affiliation(s)
- Saish Neppalli
- University of Western Australia Medical School, Perth, Western Australia 6009, Australia; Sir Charles Gairdner Hospital, Perth, Western Australia 6009, Australia
| | - Meredith A Kessell
- Department of Radiology, Royal Perth Hospital, Perth, Western Australia 6000, Australia
| | - Carolyn R Madeley
- Department of Radiology, Royal Perth Hospital, Perth, Western Australia 6000, Australia
| | | | - Philip S Vlaskovsky
- University of Western Australia Medical School, Perth, Western Australia 6009, Australia; Royal Perth Hospital Research Foundation, Perth, Western Australia 6000, Australia
| | - Donna B Taylor
- University of Western Australia Medical School, Perth, Western Australia 6009, Australia; Department of Radiology, Royal Perth Hospital, Perth, Western Australia 6000, Australia.
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23
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Clevert DA, Sidhu PS, Lim A, Ewertsen C, Mitkov V, Piskunowicz M, Ricci P, Bargallo N, Brady AP. The role of lung ultrasound in COVID-19 disease. Insights Imaging 2021; 12:81. [PMID: 34146161 PMCID: PMC8214066 DOI: 10.1186/s13244-021-01013-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/11/2021] [Indexed: 12/17/2022] Open
Abstract
This statement summarises basic settings in lung ultrasonography and best practice recommendations for lung ultrasonography in COVID-19, representing the agreed consensus of experts from the Ultrasound Subcommittee of the European Society of Radiology (ESR). Standard lung settings and artefacts in lung ultrasonography are explained for education and training, equipment settings, documentation and self-protection.
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24
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Coelho-Silva F, Gaêta-Araujo H, Rosado LPL, Freitas DQ, Haiter-Neto F, de-Azevedo-Vaz SL. Distortion or magnification? An in vitro cone-beam CT study of dimensional changes of objects with different compositions. Dentomaxillofac Radiol 2021; 50:20210063. [PMID: 34111368 DOI: 10.1259/dmfr.20210063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To assess whether dimensional changes occur as shape distortion (unevenly), contraction or magnification (evenly) in cone beam computed tomography (CBCT) considering materials, anatomical regions and metal artefact reduction algorithms. METHODS Four cylinders of amalgam (Am), cobalt-chromium (Co-Cr), gutta-percha (Gu), titanium (Ti) and zirconium (Zi) were inserted inside a polymethylmethacrylate phantom in anterior and posterior regions for acquisitions in Picasso Trio and OP300 with MAR enabled and disabled. Two observers measured the dimensions of each cylinder in three axes: Y (height), Z (antero posterior diameter) and X (latero-lateral diameter). Repeated measures ANOVA with Tukey post-hoc test compared the data (α = 5%). RESULTS Shape distortion occurred for all materials in anterior region of Picasso Trio without MAR (p < 0.05). With MAR enabled, Gu and Ti contracted (p ≥ 0.05), while the others showed distortion (p < 0.05). In posterior region, all materials distorted in both MAR conditions (p < 0.05), except Gu, which magnified without MAR (p ≥ 0.05) and contracted unevenly with MAR (p < 0.05). In anterior region of OP300, all materials magnified without MAR, (p ≥ 0.05) and had shape distortion with MAR (p < 0.05). In posterior region, only Am showed magnification without MAR (p ≥ 0.05), while all materials presented shape distortion with MAR (p < 0.05). CONCLUSION Dimensional changes of high-density materials in CBCT can be either a magnification, a contraction or a distortion; the last condition is the most prevalent. Furthermore, changes differ considering material, anatomical region and MAR condition.
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Affiliation(s)
- Fernanda Coelho-Silva
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Hugo Gaêta-Araujo
- Oral Radiology Section, School of Dentistry, Federal University of Alfenas, Minas Gerais, Brazil
| | - Lucas P Lopes Rosado
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Deborah Queiroz Freitas
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Francisco Haiter-Neto
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Sergio Lins de-Azevedo-Vaz
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil.,Department of Clinical Dentistry, Federal University of Espírito Santo, Espírito Santo, Brazil
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25
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Sumner O, Goldsmith R, Heath N, Taylor GD. The interaction and interference of preformed metal crowns on magnetic resonance imaging: a scoping review with a systematic methodology. Eur Arch Paediatr Dent 2021; 22:1023-1031. [PMID: 34115334 PMCID: PMC8629884 DOI: 10.1007/s40368-021-00644-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/31/2021] [Indexed: 11/05/2022]
Abstract
Purpose Preformed metal crowns are widely used to restore primary and permanent teeth. Children may require magnetic resonance imaging (MRI) for diagnosis and monitoring of diseases in the head and neck region. Metallic objects, in the field of view, may compromise the diagnostic value of an MRI. The impact on the diagnostic quality of an MRI in children who have had preformed metal crowns placed has not been assessed. The aim of this systematic review was to evaluate the impact that PFMCs have on MRI imaging quality and thus the overall diagnostic value. Methods Electronic searches of the following databases were completed: MEDLINE, EMBASE, Cochrane Library, Web of Science and Open Grey. Primary in vivo studies on children who had at least one preformed metal crown placed and required an MRI investigation were to be included. PRISMA guidelines were followed and screening/data extraction was carried out by two independent calibrated reviewers. Results A total of 7665 articles were identified. After removing duplicates, 7062 were identified for title and abstract screening. Thirty-four articles underwent full-text review, of which none met the inclusion criteria. Most common reasons for exclusion were not placing preformed metal crowns (n = 16) or in vitro studies (n = 12). Conclusion No in vivo studies were identified to establish the hypothetical impact preformed metal crowns would have on the diagnostic quality of an MRI in the head and neck region. Decision making needs to be guided on a case by case basis. Further high-quality clinical studies are required.
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Affiliation(s)
- O Sumner
- School of Dental Sciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.,Newcastle Upon Tyne Hospital NHS Foundation Trust, Newcastle upon Tyne, UK
| | - R Goldsmith
- Newcastle Upon Tyne Hospital NHS Foundation Trust, Newcastle upon Tyne, UK
| | - N Heath
- Newcastle Upon Tyne Hospital NHS Foundation Trust, Newcastle upon Tyne, UK
| | - G D Taylor
- School of Dental Sciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK. .,Newcastle Upon Tyne Hospital NHS Foundation Trust, Newcastle upon Tyne, UK.
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26
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Zechmeisterová K, Javanbakht H, Kvičerová J, Široký P. Against growing synonymy: Identification pitfalls of Hepatozoon and Schellackia demonstrated on North Iranian reptiles. Eur J Protistol 2021; 79:125780. [PMID: 34020115 DOI: 10.1016/j.ejop.2021.125780] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 02/09/2021] [Accepted: 02/24/2021] [Indexed: 11/17/2022]
Abstract
The analyses of molecular data represent an effective tool for increasing the credibility of taxonomy and facilitate the description of species. Nevertheless, in haemoprotozoa, the growing amount of available sequential data is not matched by the still limited number of well-defined species. We identified four protistan haemoparasites in North Iranian reptiles: two Hepatozoon and two Schellackia species. Hepatozoon colubri and Hepatozoon ophisauri were morphologically identified in their type hosts, their partial 18S rDNA was analyzed, and thorough literature data were included in their redescription. The scarce data on the detected Schellackia spp. did not allow for their formal species description. Using an integrative approach, including morphological and geographical features, host specificity, molecular data, and the data published thus far, we face the following main difficulties hindering reliable diagnosis. (1) The lack of molecular data on well-described and named species. (2) The insufficiency of using only morphological and biological features, or only sequential data without morphology, to perform an absolutely reliable species diagnosis. (3) Typical morphological features are more substantial than metric means. (4) High risk of synonymy is present in taxonomy of blood Protista. (5) Artefacts caused by blood smear processing further complicate the correct morphological determination.
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Affiliation(s)
- Kristína Zechmeisterová
- Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Palackého 1946/1, Brno 612 42, Czech Republic
| | - Hossein Javanbakht
- Department of Biology, Faculty of Science, University of Guilan, Rasht, Iran
| | - Jana Kvičerová
- Department of Parasitology, Faculty of Science, University of South Bohemia in České Budějovice, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | - Pavel Široký
- Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Palackého 1946/1, Brno 612 42, Czech Republic; CEITEC-Central European Institute of Technology, University of Veterinary and Pharmaceutical Sciences Brno, Palackého 1946/1, 612 42 Brno, Czech Republic.
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27
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Mdletshe S, Oliveira M, Twala B. Enhancing medical radiation science education through a design science research methodology. J Med Imaging Radiat Sci 2021; 52:172-8. [PMID: 33678578 DOI: 10.1016/j.jmir.2021.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/31/2020] [Accepted: 01/14/2021] [Indexed: 11/23/2022]
Abstract
Recently, there has been a call for research-informed and research-developed practice in health sciences education. This prompts the consideration of alternative suitable research approaches that could be used to enhance health sciences education practice, including medical radiation sciences education (MRSE) practice. In this discussion paper, the authors uphold design science research (DSR) methodology as a suitable research approach to enhance MRSE practice and research. An overview of the DSR methodology and an example of a project that used DSR methodology are presented to demonstrate the application of this methodology in MRSE practice and research. The paper concludes that the use of DSR methodology could be instrumental in addressing practice related challenges while developing a theoretical contribution to the discipline.
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28
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Min CK, Kim KA. Quantitative analysis of metal artefacts of dental implant in CBCT image by correlation analysis to micro-CT: A microstructural study. Dentomaxillofac Radiol 2021; 50:20200365. [PMID: 33002369 DOI: 10.1259/dmfr.20200365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
OBJECTIVES Quantification of dental implant metal artefacts in CBCT images using correlation analysis of trabecular microstructural parameters from CBCT and micro-CT, and analysis of the effect of varying the angular position of the subject. METHODS Polyurethane synthetic bone blocks were first scanned without implants by micro-CT and CBCT. Two dental implants were then placed parallel in the bone blocks and these specimens were scanned by CBCT with different alpha angles. Three volumes of interest (VOI) were set for further analysis. Six microstructural parameters were measured: trabecular thickness (TbTh), trabecular spacing (ThSp), bone volume per total volume (BV/TV), bone surface per total volume (BS/TV), connectivity density (CD) andfractal dimension (FD). Micro-CT measurements were used as a gold standard for CBCT. Spearman correlation coefficients for each microstructural parameter from CBCT and micro-CT were calculated and compared using Steiger's Z test. RESULTS Without the implants, in VOI1, the Spearman correlation coefficients of TbTh, TbSp, BV/TV, BS/TV, CD and FD were 0.599, 0.76, 0.552, 0.566, 0.664 and 0.607, respectively. With the implants, the correlation coefficients decreased sharply in VOI1. As the alpha angle increased from zero to 90°, the correlation coefficients increased and became significant. Similar results appeared in VOI2. In contrast, in VOI3, the correlation coefficient decreased as the alpha angle increased. CONCLUSIONS Metal artefacts were successfully quantified using microstructural parameters in terms of the image quality of the CBCT. Changes in alpha angle affected the quality of the CBCT image.
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Affiliation(s)
- Chang-Ki Min
- Research Institute of Clinical Medicine of Jeonbuk National University, Jeonju, South Korea.,Department of Oral and Maxillofacial Radiology, School of Dentistry, Backjedaero 567, School of Dentistry, Jeonbuk National University, Jeonju, South Korea
| | - Kyoung-A Kim
- Research Institute of Clinical Medicine of Jeonbuk National University, Jeonju, South Korea.,Department of Oral and Maxillofacial Radiology, School of Dentistry, Backjedaero 567, School of Dentistry, Jeonbuk National University, Jeonju, South Korea
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29
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Hansen TB. Signal and noise in circRNA translation. Methods 2021:S1046-2023(21)00044-X. [PMID: 33588029 DOI: 10.1016/j.ymeth.2021.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/01/2021] [Accepted: 02/05/2021] [Indexed: 11/21/2022] Open
Abstract
Within recent years, circular RNAs (circRNAs) have been an attractive new field of research in RNA biology and disease. Consequently, numerous studies have been published towards the disclosure of circRNA biogenesis and function. Initially, circRNAs were described as a subclass of cytoplasmic non-coding RNA, however, a few recent observations have proposed that circRNAs may instead be templates for protein production. The extent to which this is the case is currently debated, and therefore using rigorous data analysis and proper experimental setups is instrumental to settle the current controversies. Here, the conventional experiments used for detecting circRNA translation are outlined, and guidelines to distinguish signal from the inherent noise are discussed. While these guidelines are specific for circRNA translation, most also apply to other aspects of non-canonical translation.
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30
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Arabi H, Zaidi H. Deep learning-based metal artefact reduction in PET/CT imaging. Eur Radiol 2021; 31:6384-96. [PMID: 33569626 DOI: 10.1007/s00330-021-07709-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/31/2020] [Accepted: 01/21/2021] [Indexed: 12/12/2022]
Abstract
Objectives The susceptibility of CT imaging to metallic objects gives rise to strong streak artefacts and skewed information about the attenuation medium around the metallic implants. This metal-induced artefact in CT images leads to inaccurate attenuation correction in PET/CT imaging. This study investigates the potential of deep learning–based metal artefact reduction (MAR) in quantitative PET/CT imaging. Methods Deep learning–based metal artefact reduction approaches were implemented in the image (DLI-MAR) and projection (DLP-MAR) domains. The proposed algorithms were quantitatively compared to the normalized MAR (NMAR) method using simulated and clinical studies. Eighty metal-free CT images were employed for simulation of metal artefact as well as training and evaluation of the aforementioned MAR approaches. Thirty 18F-FDG PET/CT images affected by the presence of metallic implants were retrospectively employed for clinical assessment of the MAR techniques. Results The evaluation of MAR techniques on the simulation dataset demonstrated the superior performance of the DLI-MAR approach (structural similarity (SSIM) = 0.95 ± 0.2 compared to 0.94 ± 0.2 and 0.93 ± 0.3 obtained using DLP-MAR and NMAR, respectively) in minimizing metal artefacts in CT images. The presence of metallic artefacts in CT images or PET attenuation correction maps led to quantitative bias, image artefacts and under- and overestimation of scatter correction of PET images. The DLI-MAR technique led to a quantitative PET bias of 1.3 ± 3% compared to 10.5 ± 6% without MAR and 3.2 ± 0.5% achieved by NMAR. Conclusion The DLI-MAR technique was able to reduce the adverse effects of metal artefacts on PET images through the generation of accurate attenuation maps from corrupted CT images. Key Points • The presence of metallic objects, such as dental implants, gives rise to severe photon starvation, beam hardening and scattering, thus leading to adverse artefacts in reconstructed CT images. • The aim of this work is to develop and evaluate a deep learning–based MAR to improve CT-based attenuation and scatter correction in PET/CT imaging. • Deep learning–based MAR in the image (DLI-MAR) domain outperformed its counterpart implemented in the projection (DLP-MAR) domain. The DLI-MAR approach minimized the adverse impact of metal artefacts on whole-body PET images through generating accurate attenuation maps from corrupted CT images. Supplementary Information The online version contains supplementary material available at 10.1007/s00330-021-07709-z.
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Mancini AXM, Santos MUC, Gaêta-Araujo H, Tirapelli C, Pauwels R, Oliveira-Santos C. Artefacts at different distances from titanium and zirconia implants in cone-beam computed tomography: effect of tube current and metal artefact reduction. Clin Oral Investig 2021; 25:5087-5094. [PMID: 33544197 DOI: 10.1007/s00784-021-03821-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 01/29/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To evaluate the effect of cone-beam computed tomography (CBCT) tube current (mA) on the magnitude of artefacts at different distances from titanium or zirconia implants, with and without activation of a proprietary metal artefact reduction (MAR). MATERIAL AND METHODS Human mandibles were scanned on an OP300 Maxio CBCT unit (Instrumentarium, Tuusula, Finland) before and after the installation of dental implants, with four different tube currents (4 mA, 6.3 mA, 8 mA and 10 mA), with and without activation of proprietary MAR. The effect of mA on the standard deviation (SD) of gray values and contrast to noise ratio (CNR) were assessed in regions of interest located 1.5 cm, 2.5 cm, and 3.5 cm from implants. RESULTS In the presence of titanium implants, a significant decrease in SD was found by increasing tube current from 4 mA to 6.3 mA or 8 mA. For zirconia implants, 8 mA yielded better results for all distances. MAR improved CNR in the presence of zirconia implants at all distances, whereas no differences were observed with the use of MAR for titanium implants. CONCLUSION Increased tube current can improve overall image quality in the presence of implants, at all the distances tested. When a zirconia implant is present, such increase in mA should be higher in comparison to that for examinations with titanium implants. Activation of OP300 Maxio proprietary MAR improved image quality only among examinations with zirconia implants. CLINICAL RELEVANCE Artefact-generating implants are common in the field of view of CBCT examinations. Optimal exposure parameters, such as tube current, ensure high image quality with lowest possible radiation exposure.
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Affiliation(s)
- Arthur Xavier Maseti Mancini
- Department of Dental Materials and Prosthodontics, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Av. Do Café, s/n, Ribeirao Preto, Sao Paulo, 14040-904, Brazil.
| | - Matheus Urias Cruz Santos
- Department of Stomatology, Public Oral Health and Forensic Dentistry, Division of Oral Radiology, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Av. Do Café, s/n, Ribeirao Preto, Sao Paulo, 14040-904, Brazil
| | - Hugo Gaêta-Araujo
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Av. Limeira, 901, Piracicaba, São Paulo, 13414-903, Brazil
| | - Camila Tirapelli
- Department of Dental Materials and Prosthodontics, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Av. Do Café, s/n, Ribeirao Preto, Sao Paulo, 14040-904, Brazil
| | - Ruben Pauwels
- Medical Physics & Quality Assessment, Department of Imaging & Pathology, Catholic University of Leuven, Leuven, Belgium and Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, 8000, Aarhus, Denmark
| | - Christiano Oliveira-Santos
- Department of Stomatology, Public Oral Health and Forensic Dentistry, Division of Oral Radiology, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Av. Do Café, s/n, Ribeirao Preto, Sao Paulo, 14040-904, Brazil
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Rodrigues CT, Jacobs R, Vasconcelos KF, Lambrechts P, Rubira-Bullen IRF, Gaêta-Araujo H, Oliveira-Santos C, Duarte MAH. Influence of CBCT-based volumetric distortion and beam hardening artefacts on the assessment of root canal filling quality in isthmus-containing molars. Dentomaxillofac Radiol 2021; 50:20200503. [PMID: 33400563 DOI: 10.1259/dmfr.20200503] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVES To evaluate the influence of artefacts in cone beam CT (CBCT) images of filled root canals in isthmus-containing molars. METHODS 10 teeth presenting canals with an isthmus were instrumented and filled with a thermoplasticised obturation technique. The teeth were scanned using a micro-CT device and two CBCT devices: 3D Accuitomo 170 (ACC) and NewTom VGi evo (NT), with different acquisition protocols: larger and smaller voxel size. Three examiners assessed the CBCT images for: (1) detection of filling voids; (2) assessment of under- or overestimation of the filling material and (3) resemblance of CBCT images to the reference standard. Analyses of Task 1 yielded accuracy, sensitivity and specificity for detection of filling voids. For tasks 2 and 3, statistical analysis was performed using Wilcoxon test. The level of significance was set at p < .05. RESULTS For Task 1, ACC showed higher sensitivity, whereas NT presented higher specificity. No significant difference was found between the protocols in ACC, however, for NT, differences between protocols were significant for all diagnostic values. In Task 2, visualisation of the filling was overestimated for NT, while for ACC, underestimation was observed. For Task 3, images with smaller voxel size were more similar to the reference image, for both CBCT devices. CONCLUSIONS Different artefacts compromise the detection of filling voids on CBCT images of canals in mandibular molars with isthmus. ACC and NT present rather similar diagnostic accuracy, even though artefact expression remains device-specific.
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Affiliation(s)
- Clarissa Teles Rodrigues
- Department of Restorative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil
| | - Reinhilde Jacobs
- Department of Imaging and Pathology, Faculty of Medicine, OMFS IMPATH Research Group, KU Leuven, Leuven, Belgium.,Department of Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium.,Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Karla Faria Vasconcelos
- Department of Imaging and Pathology, Faculty of Medicine, OMFS IMPATH Research Group, KU Leuven, Leuven, Belgium.,Department of Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Paul Lambrechts
- Department of Oral Health Sciences, Endodontology, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium.,Biomaterials-BIOMAT, Leuven, Belgium
| | | | - Hugo Gaêta-Araujo
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, São Paulo, Brazil
| | - Christiano Oliveira-Santos
- Department of Stomatology, Public Oral Health, and Forensic Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Marco Antonio Hungaro Duarte
- Department of Restorative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil
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McElroy S, Winfield JM, Westerland O, Charles-Edwards G, Bell J, Neji R, Stemmer A, Kiefer B, Streetly M, Goh V. Integrated slice-specific dynamic shimming for whole-body diffusion-weighted MR imaging at 1.5 T. MAGMA 2020; 34:513-521. [PMID: 33355719 PMCID: PMC8338872 DOI: 10.1007/s10334-020-00898-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 01/11/2023]
Abstract
Objective To compare integrated slice-specific dynamic shim (iShim) with distortion correction post-processing to conventional 3D volume shim for the reduction of artefacts and signal loss in 1.5 T whole-body diffusion-weighted imaging (WB-DWI). Methods Ten volunteers underwent WB-DWI using conventional 3D volume shim and iShim. Forty-eight consecutive patients underwent WB-DWI with either volume shim (n = 24) or iShim (n = 24) only. For all subjects, displacement of the spinal cord at imaging station interfaces was measured on composed b = 900 s/mm2 images. The signal intensity ratios, computed as the average signal intensity in a region of high susceptibility gradient (sternum) divided by the average signal intensity in a region of low susceptibility gradient (vertebral body), were compared in volunteers. For patients, image quality was graded from 1 to 5 (1 = Poor, 5 = Excellent). Signal intensity discontinuity scores were recorded from 1 to 4 (1 = 2 + steps, 4 = 0 steps). A p value of < 0.05 was considered significant. Results Spinal cord displacement artefacts were lower with iShim (p < 0.05) at the thoracic junction in volunteers and at the cervical and thoracic junctions in patients (p < 0.05). The sternum/vertebra signal intensity ratio in healthy volunteers was higher with iShim compared with the volume shim sequence (p < 0.05). There were no significant differences between the volume shim and iShim patient groups in terms of image quality and signal intensity discontinuity scores. Conclusion iShim reduced the degree of spinal cord displacement artefact between imaging stations and susceptibility-gradient-induced signal loss. Supplementary Information The online version contains supplementary material available at 10.1007/s10334-020-00898-6.
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Affiliation(s)
- Sarah McElroy
- Clinical Imaging and Medical Physics, Guy's and St Thomas' Hospital, London, UK.
| | - Jessica M Winfield
- Clinical Imaging and Medical Physics, Guy's and St Thomas' Hospital, London, UK
| | - Olwen Westerland
- Clinical Imaging and Medical Physics, Guy's and St Thomas' Hospital, London, UK
| | | | - Joanna Bell
- Clinical Imaging and Medical Physics, Guy's and St Thomas' Hospital, London, UK
| | - Radhouene Neji
- MR Research Collaborations, Siemens Healthcare, Frimley, UK
| | - Alto Stemmer
- MR Application Predevelopment, Siemens Healthcare, Erlangen, Germany
| | - Berthold Kiefer
- MR Application Predevelopment, Siemens Healthcare, Erlangen, Germany
| | - Matthew Streetly
- Clinical Haematology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Vicky Goh
- Clinical Imaging and Medical Physics, Guy's and St Thomas' Hospital, London, UK.,Department of Cancer Imaging, School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
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Candemil AP, Mangione F, Vasconcelos KF, Oenning AC, Jacobs R, Freitas DQ, Haiter-Neto F, Salmon B, Oliveira ML. Influence of the exomass on the detection of simulated root fracture in cone-beam CT - an ex-vivo study. Dentomaxillofac Radiol 2020; 50:20200450. [PMID: 33237809 DOI: 10.1259/dmfr.20200450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVES To evaluate the influence of exomass-related metal artefacts on the detection of simulated vertical root fracture (VRF) in cone-beam computed tomography (CBCT). METHODS 20 teeth were endodontically instrumented and VRF was induced in half of them. All teeth were individually placed in an empty socket of a human mandible. Metallic materials were differently arranged in the exomass [zone outside of the field of view (FOV) but between the X-ray source and the receptor] and/or endomass (zone inside of the FOV), and CBCT scans were obtained. Four radiologists evaluated the presence of VRF using a 5-point scale. Sensitivity, specificity, and area under the receiver operating curve (AUC) were compared using ANOVA. Also, the tooth of interest was replaced with a tube filled with a radiopaque solution and all CBCT scans were repeated to analyse the data objectively. Mean grey and noise values were obtained from the tube and compared using ANOVA followed by Tukey's test (α = 0.05). RESULTS Mean grey values were significantly lower and noise was significantly higher when metallic materials were present in the endomass or both the exomass and endomass. Sensitivity, specificity, and AUC were not influenced by the artefacts from the metallic materials irrespective of the arrangement condition. CONCLUSIONS Exomass-related metal artefacts did not influence the diagnosis of simulated VRF in CBCT.
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Affiliation(s)
- Amanda Pelegrin Candemil
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil
| | - Francesca Mangione
- Orofacial Pathologies, Imaging and Biotherapies Lab, Université de Paris, UR 2496, Montrouge, France.,Dental Medicine Departments, Bretonneau and Henri Mondor University Hospitals, AP-HP, Paris, France
| | - Karla Farias Vasconcelos
- OMFS-IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, Catholic University of Leuven, and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Anne Caroline Oenning
- Orofacial Pathologies, Imaging and Biotherapies Lab, Université de Paris, UR 2496, Montrouge, France.,Dental Medicine Departments, Bretonneau and Henri Mondor University Hospitals, AP-HP, Paris, France.,Division of Oral Radiology, Faculdade São Leopoldo Mandic, Instituto de Pesquisas São Leopoldo Mandic, Campinas, Sao Paulo, Brazil
| | - Reinhilde Jacobs
- OMFS-IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, Catholic University of Leuven, and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium.,Department of Dental Medicine, Karolinska Institute, Stockholm, Sweden
| | - Deborah Queiroz Freitas
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil
| | - Francisco Haiter-Neto
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil
| | - Benjamin Salmon
- Orofacial Pathologies, Imaging and Biotherapies Lab, Université de Paris, UR 2496, Montrouge, France.,Dental Medicine Departments, Bretonneau and Henri Mondor University Hospitals, AP-HP, Paris, France
| | - Matheus Lima Oliveira
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil
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Plodeck V, Radosa CG, Hübner HM, Baldus C, Borkowetz A, Thomas C, Kühn JP, Laniado M, Hoffmann RT, Platzek I. Rectal gas-induced susceptibility artefacts on prostate diffusion-weighted MRI with epi read-out at 3.0 T: does a preparatory micro-enema improve image quality? Abdom Radiol (NY) 2020; 45:4244-4251. [PMID: 32500236 PMCID: PMC8260527 DOI: 10.1007/s00261-020-02600-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/20/2020] [Accepted: 05/26/2020] [Indexed: 12/21/2022]
Abstract
Purpose To assess whether the application of a preparatory micro-enema reduces gas-induced susceptibility artefacts on diffusion-weighted MRI of the prostate. Methods 114 consecutive patients who received multiparametric 3 T MRI of the prostate at our institution were retrospectively enrolled. 63 patients self-administered a preparatory micro-enema prior to imaging, and 51 patients underwent MRI without bowel preparation. Two blinded readers independently reviewed the diffusion-weighted sequences regarding gas-induced artefacts. The presence/severity of artefacts was scored ranging from 0 (no artefact) to 3 (severe artefact). A score ≥ 2 was considered a clinically relevant artefact. Maximum rectal width at the level of the prostate was correlated with the administration of a micro-enema. Scores were compared between the scans performed with and without bowel preparation using univariable and multivariable logistic regression, taking into account potential confounding factors (age and prostate volume). Results Significantly less artefacts were found on diffusion-weighted sequences after the administration of a micro-enema shortly prior to MR imaging. Clinically relevant artefacts were found in 10% in the patient group after enema, in 41% without enema. If present, artefacts were also significantly less severe. Mean severity score was 0.3 (enema administered) and 1.2 (no enema), and odds ratio was 0.137 (p < 0.0001) in univariable ordinal logistic regression. Inter-observer agreement was excellent (κ 0.801). Conclusion The use of a preparatory micro-enema prior to 3 T multiparametric prostate MRI significantly reduces both the incidence and severity of gas-induced artefacts on diffusion-weighted sequences and thus improves image quality. Electronic supplementary material The online version of this article (10.1007/s00261-020-02600-9) contains supplementary material, which is available to authorized users.
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Malfilâtre G, Mony L, Hasaerts D, Vignolo-Diard P, Lamblin MD, Bourel-Ponchel E. Technical recommendations and interpretation guidelines for electroencephalography for premature and full-term newborns. Neurophysiol Clin 2020; 51:35-60. [PMID: 33168466 DOI: 10.1016/j.neucli.2020.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/05/2020] [Accepted: 10/05/2020] [Indexed: 10/23/2022] Open
Abstract
Electroencephalography (EEG) of neonatal patients is amongst the most valuable diagnostic and prognostic tool. EEG recordings, acquired at the bedside of infants, evaluate brain function and the maturation of premature and extremely premature infants. Strict conditions of acquisition and interpretation must be respected to guarantee the quality of the EEG and ensure its safety for fragile children. This article provides guidance for EEG acquisition including: (1) the required equipment and devices, (2) the modalities of installation and asepsis precautions, and (3) the digital signal acquisition parameters to use during the recording. The fundamental role of a well-trained technician in supervising the EEG recording is emphasized. In parallel to the acquisition recommendations, we present a guideline for EEG interpretation and reporting. The successive steps of EEG interpretation, from reading the EEG to writing the report, are described. The complexity of the EEG signal in neonates makes artefact detection difficult. Thus, we provide an overview of certain characteristic artefacts and detail the methods for eliminating them.
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Affiliation(s)
| | - Luc Mony
- Neurophysiology Unit, Le Mans Hospital Center, 72037 Le Mans Cedex, France
| | - Danièle Hasaerts
- Dienst Kinderneurologie, UZ Brussel, Laerbeeklaan 101, 1090 Brussels, Belgium
| | - Patricia Vignolo-Diard
- Department of Clinical Neurophysiology, APHP, Necker-Enfants Malades Hospital, Paris, France
| | | | - Emilie Bourel-Ponchel
- INSERM UMR 1105, Research Group on Multimodal Analysis of Brain Function, University of Picardie Jules Verne, 80036 Amiens Cedex, France; INSERM UMR 1105, Pediatric Neurophysiology Unit, Amiens University Hospital, 80054 Amiens Cedex, France.
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Kim YY, Kim MJ, Gho SM, Seo N. Comparison of multiplexed sensitivity encoding and single-shot echo-planar imaging for diffusion-weighted imaging of the liver. Eur J Radiol 2020; 132:109292. [PMID: 32992144 DOI: 10.1016/j.ejrad.2020.109292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 07/22/2020] [Accepted: 09/14/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To compare multiplexed sensitivity encoding (MUSE) and conventional diffusion-weighted magnetic resonance imaging (cDWI) techniques in liver MRI. METHODS Fifty-nine patients who underwent both two-shot echo-planar DWI using MUSE and single-shot echo-planar cDWI at a 3.0-T MRI system were included. Qualitative parameters were independently evaluated by three radiologists, and quantitative parameters were calculated on the basis of region of interest measurements. Receiver operating characteristic curve analysis and McNemar's test were used to compare solid lesion characterization results and lesion detectability, respectively. RESULTS All reviewers found less image noise, sharper liver contours, milder susceptibility artifacts, and better lesion conspicuity in MUSE-DWI than in cDWI (reader average mean, 4.1-4.5 vs. 3.5-4.0; p < 0.05). The signal-to-noise ratio (SNR) of the liver was significantly higher in MUSE-DWI than in cDWI (right lobe: mean, 9.39 vs. 8.10, p < 0.001; left lobe: mean, 8.34 vs. 7.19, p < 0.001), while the SNR of the lesion (mean, 23.72 vs. 23.88, p = 0.911) and lesion-to-liver contrast-to-noise ratio (mean, 14.65 vs. 15.41, p = 0.527) were comparable between MUSE-DWI and cDWI. Solid lesion characterization results were comparably accurate between MUSE-DWI and cDWI (reader average area under the receiver operating characteristic curve, 0.985 vs. 0.986, p = 0.480). The detectability of lesions was better in MUSE-DWI than in cDWI (reader consensus, 83.7 % [41/49] vs. 67.3 % [33/49], p = 0.021). CONCLUSION MUSE-DWI can provide multi-shot liver DWI with less noise, fewer distortions, improved SNR of the liver, and better lesion detectability.
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Affiliation(s)
- Yeun-Yoon Kim
- Department of Radiology, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
| | - Myeong-Jin Kim
- Department of Radiology, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
| | - Sung-Min Gho
- MR Collaboration & Development, GE Healthcare, 416 Hangang-daero, Jung-gu, Seoul, 04637, Republic of Korea.
| | - Nieun Seo
- Department of Radiology, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
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Rocchi L, Di Santo A, Brown K, Ibáñez J, Casula E, Rawji V, Di Lazzaro V, Koch G, Rothwell J. Disentangling EEG responses to TMS due to cortical and peripheral activations. Brain Stimul 2020; 14:4-18. [PMID: 33127580 DOI: 10.1016/j.brs.2020.10.011] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 08/18/2020] [Accepted: 10/21/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND the use of combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG) for the functional evaluation of the cerebral cortex in health and disease is becoming increasingly common. However, there is still some ambiguity regarding the extent to which brain responses to auditory and somatosensory stimulation contribute to the TMS-evoked potential (TEP). OBJECTIVE/HYPOTHESIS to measure separately the contribution of auditory and somatosensory stimulation caused by TMS, and to assess their contribution to the TEP waveform, when stimulating the motor cortex (M1). METHODS 19 healthy volunteers underwent 7 blocks of EEG recording. To assess the impact of auditory stimulation on the TEP waveform, we used a standard figure of eight coil, with or without masking with a continuous noise reproducing the specific time-varying frequencies of the TMS click, stimulating at 90% of resting motor threshold. To further characterise auditory responses due to the TMS click, we used either a standard or a sham figure of eight coil placed on a pasteboard cylinder that rested on the scalp, with or without masking. Lastly, we used electrical stimulation of the scalp to investigate the possible contribution of somatosensory activation. RESULTS auditory stimulation induced a known pattern of responses in electrodes located around the vertex, which could be suppressed by appropriate noise masking. Electrical stimulation of the scalp alone only induced similar, non-specific scalp responses in the in the central electrodes. TMS, coupled with appropriate masking of sensory input, resulted in specific, lateralized responses at the stimulation site, lasting around 300 ms. CONCLUSIONS if careful control of confounding sources is applied, TMS over M1 can generate genuine, lateralized EEG activity. By contrast, sensory evoked responses, if present, are represented by non-specific, late (100-200 ms) components, located at the vertex, possibly due to saliency of the stimuli. Notably, the latter can confound the TEP if masking procedures are not properly used.
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Affiliation(s)
- Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG, London, United Kingdom.
| | - Alessandro Di Santo
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG, London, United Kingdom; Neurology, Neurophysiology and Neurobiology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Katlyn Brown
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG, London, United Kingdom
| | - Jaime Ibáñez
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG, London, United Kingdom; Department of Bioengineering, Faculty of Engineering, Imperial College London, SW7 2AZ, London, United Kingdom
| | - Elias Casula
- Non-invasive Brain Stimulation Unit, IRCCS Santa Lucia Foundation, Via Ardeatina 306/354, 00142, Rome, Italy
| | - Vishal Rawji
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG, London, United Kingdom
| | - Vincenzo Di Lazzaro
- Neurology, Neurophysiology and Neurobiology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Giacomo Koch
- Non-invasive Brain Stimulation Unit, IRCCS Santa Lucia Foundation, Via Ardeatina 306/354, 00142, Rome, Italy
| | - John Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG, London, United Kingdom
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Cammarota G, Santangelo E, Lauro G, Verdina F, Boniolo E, De Vita N, Tarquini R, Spinelli E, Garofalo E, Bruni A, Zanoni M, Messina A, Pesenti A, Corte FD, Navalesi P, Vaschetto R, Mauri T. Esophageal balloon calibration during Sigh: A physiologic, randomized, cross-over study. J Crit Care 2020; 61:125-132. [PMID: 33157308 DOI: 10.1016/j.jcrc.2020.10.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/15/2020] [Accepted: 10/19/2020] [Indexed: 12/26/2022]
Abstract
PURPOSE Optimal esophageal balloon filling volume (Vbest) depends on the intrathoracic pressure. During Sigh breath delivered by the ventilator machine, esophageal balloon is surrounded by elevated intrathoracic pressure that might require higher filling volume for accurate measure of tidal changes in esophageal pressure (Pes). The primary aim of our investigation was to evaluate and compare Vbest during volume controlled and pressure support breaths vs. Sigh breath. MATERIALS AND METHODS Twenty adult patients requiring invasive volume-controlled ventilation (VCV) for hypoxemic acute respiratory failure were enrolled. After the insertion of a naso-gastric catheter equipped with 10 ml esophageal balloon, each patient underwent three 30-min trials as follows: VCV, pressure support ventilation (PSV), and PSV + Sigh. Sigh was added to PSV as 35 cmH2O pressure-controlled breath over 4 s, once per minute. PSV and PSV + Sigh were randomly applied and, at the end of each step, esophageal balloon calibration was performed. RESULTS Vbest was higher for Sigh breath (4.5 [3.0-6.8] ml) compared to VCV (1.5 [1.0-2.9] ml, P = 0.0004) and PSV tidal breath (1.0 [0.5-2.4] ml, P < 0.0001). CONCLUSIONS During Sigh breath, applying a calibrated approach for Pes assessment, a higher Vbest was required compared to VCV and PSV tidal breath.
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Affiliation(s)
- Gianmaria Cammarota
- Anesthesia and General Intensive Care, "Maggiore della Carità" University Hospital, Novara, Italy.
| | - Erminio Santangelo
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Gianluigi Lauro
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Federico Verdina
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Ester Boniolo
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Nello De Vita
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Riccardo Tarquini
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Elena Spinelli
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Eugenio Garofalo
- Department of Medical and Surgical Science, Università Magna Greacia, Catanzaro, Italy
| | - Andrea Bruni
- Department of Medical and Surgical Science, Università Magna Greacia, Catanzaro, Italy
| | - Marta Zanoni
- Anesthesia and General Intensive Care, "Maggiore della Carità" University Hospital, Novara, Italy
| | - Antonio Messina
- Humanitas Clinical and Research Center - IRCCS - Rozzano, Milano, Italy
| | - Antonio Pesenti
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Francesco Della Corte
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | | | - Rosanna Vaschetto
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Tommaso Mauri
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
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Ferreira LC, Maul JE, Viana MVC, de Sousa TJ, de Carvalho Azevedo VA, Roberts DP, de Souza JT. Complete genome sequence of the biocontrol agent Serratia marcescens strain N4-5 uncovers an assembly artefact. Braz J Microbiol 2020; 52:245-250. [PMID: 32965626 DOI: 10.1007/s42770-020-00382-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 09/15/2020] [Indexed: 10/23/2022] Open
Abstract
Serratia marcescens are gram-negative bacteria found in several environmental niches, including the plant rhizosphere and patients in hospitals. Here, we present the genome of Serratia marcescens strain N4-5 (=NRRL B-65519), which has a size of 5,074,473 bp (664-fold coverage) and contains 4840 protein coding genes, 21 RNA genes, and an average G + C content of 59.7%. N4-5 harbours a plasmid of 11,089 bp and 43.5% G + C content that encodes six unique CDS repeated 2.5× times totalling 13 CDS. Our genome assembly and manual curation uncovered the insertion of two extra copies of the 5S rRNA gene in the assembled sequence, which was confirmed by PCR and Sanger sequencing to be a misassembly. This artefact was subsequently removed from the final assembly. The occurrence of extra copies of the 5S rRNA gene was also observed in most complete genomes of Serratia spp. deposited in public databases in our comparative analysis. These elements, which also occur naturally, can easily be confused with true genetic variation. Efforts to discover and correct assembly artefacts should be made in order to generate genome sequences that represent the biological truth underlying the studied organism. We present the genome of N4-5 and discuss genes potentially involved in biological control activity against plant pathogens and also the possible mechanisms responsible for the artefact we observed in our initial assembly. This report raises awareness about the extra copies of the 5S rRNA gene in sequenced bacterial genomes as they may represent misassemblies and therefore should be verified experimentally.
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Affiliation(s)
- Larissa Carvalho Ferreira
- Plant Pathology Department, Federal University of Lavras, Lavras, MG, 37200-000, Brazil.,Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3DA, UK
| | - Jude E Maul
- Sustainable Agricultural Systems Laboratory, USDA-Agricultural Research Service, Beltsville, MD, 20705, USA
| | | | - Thiago Jesus de Sousa
- Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
| | | | - Daniel P Roberts
- Sustainable Agricultural Systems Laboratory, USDA-Agricultural Research Service, Beltsville, MD, 20705, USA
| | - Jorge Teodoro de Souza
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3DA, UK.
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41
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Christiansen SN, Müller FC, Østergaard M, Slot O, Møller JM, Børgesen HF, Gosvig KK, Terslev L. Dual-energy CT in gout patients: Do all colour-coded lesions actually represent monosodium urate crystals? Arthritis Res Ther 2020; 22:212. [PMID: 32917279 PMCID: PMC7488422 DOI: 10.1186/s13075-020-02283-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/31/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Dual-energy CT (DECT) can acknowledge differences in tissue compositions and can colour-code tissues with specific features including monosodium urate (MSU) crystals. However, when evaluating gout patients, DECT frequently colour-codes material not truly representing MSU crystals and this might lead to misinterpretations. The characteristics of and variations in properties of colour-coded DECT lesions in gout patients have not yet been systematically investigated. The objective of this study was to evaluate the properties and locations of colour-coded DECT lesions in gout patients. METHODS DECT of the hands, knees and feet were performed in patients with suspected gout using factory default gout settings, and colour-coded DECT lesions were registered. For each lesion, properties [mean density (mean of Hounsfield Units (HU) at 80 kV and Sn150kV), mean DECT ratio and size] and location were determined. Subgroup analysis was performed post hoc evaluating differences in locations of lesions when divided into definite MSU depositions and possibly other lesions. RESULTS In total, 4033 lesions were registered in 27 patients (23 gout patients, 3918 lesions; 4 non-gout patients, 115 lesions). In gout patients, lesions had a median density of 160.6 HU and median size of 6 voxels, and DECT ratios showed an approximated normal distribution (mean 1.06, SD 0.10), but with a right heavy tail consistent with the presence of smaller amounts of high effective atomic number lesions (e.g. calcium-containing lesions). The most common locations of lesions were 1st metatarsophalangeal (MTP1), knee and midtarsal joints along with quadriceps and patella tendons. Subgroup analyses showed that definite MSU depositions (large volume, low DECT ratio, high density) had a similar distribution pattern, whereas possible calcium-containing material (high DECT ratio) and non-gout MSU-imitating lesions (properties as definite MSU depositions in non-gout patients) were primarily found in some larger joints (knee, midtarsal and talocrural) and tendons (Achilles and quadriceps). MTP1 joints and patella tendons showed only definite MSU depositions. CONCLUSION Colour-coded DECT lesions in gout patients showed heterogeneity in properties and distribution. MTP1 joints and patella tendons exclusively showed definite MSU depositions. Hence, a sole focus on these regions in the evaluation of gout patients may improve the specificity of DECT scans.
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Affiliation(s)
- Sara Nysom Christiansen
- Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Glostrup, Valdemar Hansens Vej 17, 2600, Glostrup, Denmark. .,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Felix Christoph Müller
- Department of Radiology, Herlev and Gentofte Hospital, Herlev, Denmark.,Siemens Healthineers, Ballerup, Denmark
| | - Mikkel Østergaard
- Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Glostrup, Valdemar Hansens Vej 17, 2600, Glostrup, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Ole Slot
- Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Glostrup, Valdemar Hansens Vej 17, 2600, Glostrup, Denmark
| | - Jakob M Møller
- Department of Radiology, Herlev and Gentofte Hospital, Herlev, Denmark
| | - Henrik F Børgesen
- Department of Radiology, Herlev and Gentofte Hospital, Herlev, Denmark
| | | | - Lene Terslev
- Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Glostrup, Valdemar Hansens Vej 17, 2600, Glostrup, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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Fontenele RC, Farias Gomes A, Rosado LPL, Neves FS, Freitas DQ. Mapping the expression of beam hardening artefacts produced by metal posts positioned in different regions of the dental arch. Clin Oral Investig 2020; 25:571-579. [PMID: 32772328 DOI: 10.1007/s00784-020-03494-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 08/03/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVES To objectively assess the expression and direction of artefacts in the vicinity of metal posts positioned in different mandibular regions. MATERIALS AND METHODS A human mandible had two sockets prepared-anterior and posterior regions-to accommodate a single-rooted tooth. Two CBCT units, Picasso Trio and OP300, were used. CBCT images of the tooth without metal post, and with silver-palladium, nickel-chromium, or cobalt-chromium posts (experimental groups) were individually acquired. Then, 8 lines of interest (LOIs) were determined around the root canal, in an axial reconstruction: 4 in orthogonal (buccal, lingual, mesial, and distal) directions, and 4 in oblique (mesiobuccal, distobuccal, mesiolingual, and distolingual) directions. The mean of gray values was measured for each LOI. RESULTS For the OP300, in general, all experimental groups showed greater expression of hyperdense streaks in orthogonal LOIs and greater expression of hypodense streaks in oblique LOIs. For the Picasso Trio, for both mandibular regions, the buccal LOI showed greater expression of hypodense streaks; conversely, greater expression of hyperdense streaks was observed in the distal and distobuccal LOIs in the anterior region and in the mesiolingual LOI in the posterior region. The silver-palladium group showed significantly greater expression of beam hardening artefacts in the posterior region of the mandible, regardless of the CBCT unit (p < 0.05). The mandibular posterior region showed significantly lower gray values than the anterior region (p < 0.05). CONCLUSION The expression and direction of artefacts produced in the vicinity of metal posts vary according to the mandibular region, composition of the post, and CBCT unit. CLINICAL RELEVANCE The mapping of artefacts produced by metal posts reveals the root regions with greater expression of hypodense and hyperdense artefacts, which may contribute to recognizing regions more likely to mimic or hide root fracture lines.
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Affiliation(s)
- Rocharles C Fontenele
- Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Av. Limeira, 901, Piracicaba, SP, 13414-903, Brazil.
| | - Amanda Farias Gomes
- Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Av. Limeira, 901, Piracicaba, SP, 13414-903, Brazil
| | - Lucas P Lopes Rosado
- Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Av. Limeira, 901, Piracicaba, SP, 13414-903, Brazil
| | - Frederico S Neves
- Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Av. Limeira, 901, Piracicaba, SP, 13414-903, Brazil.,Department of Propedeutics and Integrated Clinic, Division of Oral Radiology, School of Dentistry, Federal University of Bahia, Salvador, BA, Brazil
| | - Deborah Q Freitas
- Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Av. Limeira, 901, Piracicaba, SP, 13414-903, Brazil
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Stumm CJP, Wittig H, Kalberer NM, Scheurer E. Histomorphological assessment of isolated abdominal organs after targeted perfusion with the contrast agent Angiofil® in postmortem computed tomography angiography. Forensic Sci Int 2020; 315:110427. [PMID: 32771885 DOI: 10.1016/j.forsciint.2020.110427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 10/23/2022]
Abstract
The current literature about histological alterations and artefacts associated with postmortem computed tomography angiography (PMCTA) is scarce and limited to qualitative research. The aim of this study was to describe and quantify histological alterations and artefacts in histologic specimens of the inner organs. The spleen, the liver, the kidneys and the pancreas were eviscerated in the course of standard forensic autopsy, followed by manual arterial and venous perfusion of the organs with the lipophilic contrast agent Angiofil®. Computed tomography (CT) of the organ packages was executed to evaluate if the perfusion with Angiofil® was sufficient. The CT scans revealed a good delineation of the vessel trees up to the organ periphery, suggesting a sufficient perfusion. Tissue samples were taken before and after perfusion, stained with hematoxylin-eosin (H&E) and examined by using microscopy. Native and perfused specimens were assessed on the basis of a qualitative rating scale in regard to the integrity of the cells, the tissue architecture and induced alterations. Subsequently the observed differences before and after perfusion with Angiofil® were analyzed quantitatively. While the liver, spleen and kidneys could be evaluated, further microscopic examinations of the pancreatic tissue were not possible due to vast autolytic changes. On the cellular level no changes in the liver, spleen and kidneys were observed after administering Angiofil®. While the tissue architecture of these organs remained intact, a significant blood volume displacement occurred. As a consequence, tissue with hypoemic or normal blood state demonstrated congestion. Further, optically empty spaces emerged regularly in the vessels and the parenchyma of each organ as a surrogate for the lipophilic contrast agent. With a few exceptions an adequate perfusion up to the microscopic level was observed. Following the results of this investigation, CT-controlled manual injection of Angiofil® into isolated organs may be an alternative to the generalized in situ application of contrast agents in the course of PMCTA. It is of eminent importance to know the artefacts induced by an Angiofil® injection in order to avoid a misinterpretation or a masking of findings. Thus, a collection of native tissue specimens has to be done before contrast agent application.
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Affiliation(s)
- Christian Jean-Paul Stumm
- Institute of Forensic Medicine, University Basel, Health Department Basel-Stadt, Pestalozzistrasse 22, 4056 Basel, Switzerland.
| | - Holger Wittig
- Institute of Forensic Medicine, University Basel, Health Department Basel-Stadt, Pestalozzistrasse 22, 4056 Basel, Switzerland.
| | - Nicole M Kalberer
- Institute of Forensic Medicine, University Basel, Health Department Basel-Stadt, Pestalozzistrasse 22, 4056 Basel, Switzerland.
| | - Eva Scheurer
- Institute of Forensic Medicine, University Basel, Health Department Basel-Stadt, Pestalozzistrasse 22, 4056 Basel, Switzerland.
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Nazarova EE, Tereshchenko GV, Kupriyanov DA, Smetanina NS, Novichkova GA. Free-breathing T2* mapping for MR myocardial iron assessment at 3 T. Eur Radiol Exp 2020; 4:25. [PMID: 32303909 PMCID: PMC7165216 DOI: 10.1186/s41747-020-00156-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 03/19/2020] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Timely diagnosis of cardiac iron overload is important for children with transfusion-dependent anaemias and requires modern measure methods. Nowadays, myocardial iron quantification is performed by magnetic resonance (MR) breath-hold techniques, sensitive to respiratory motion and unfeasible in patients who are unable to hold their breath. Free-breathing T2* mapping sequences would allow to scan children who cannot hold their breath for a specified duration. Our aim was to test a free-breathing T2* mapping sequence, based on motion correction by multiple signal accumulation technique. METHODS We used an electrocardiographically gated T2* mapping sequence based on multiple gradient echo at 3-T in 37 paediatric patients with haematologic disorders aged from 2 to 16. We compared T2* values of myocardium and signal-to-noise ratio of this new sequence with standard breath-holding T2* mapping sequence. T2* values were measured in the interventricular septum for both methods in studies with adequate image quality. RESULTS All children were scanned without complications. Five patients were excluded from analysis because of the presence of respiratory artefacts on the T2* images with breath-holding technique due to patient's inability to hold their breath. Breath-holding T2* was 19.5 ± 7.7 ms (mean ± standard deviation), free-breathing T2* was 19.4 ± 7.6 ms, with positive correlation (r = 0.99, R2 = 0.98; p < 0.001). The free-breathing sequence had a higher signal-to-noise ratio (median 212.8, interquartile range 148.5-566.5) than the breath-holding sequence (112.6, 71.1-334.1) (p = 0.03). CONCLUSION A free-breathing sequence provided accurate measurement of myocardial T2* values in children.
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Affiliation(s)
- E E Nazarova
- Radiology department, Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Samory Mashela st., 1, Moscow, Russia, 117997.
| | - G V Tereshchenko
- Radiology department, Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Samory Mashela st., 1, Moscow, Russia, 117997
| | - D A Kupriyanov
- Radiology department, Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Samory Mashela st., 1, Moscow, Russia, 117997
- Philips Healthcare, Moscow, Russia
| | - N S Smetanina
- Radiology department, Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Samory Mashela st., 1, Moscow, Russia, 117997
- 3Pirogov Russian National Research Medical University, Moscow, Russia
| | - G A Novichkova
- Radiology department, Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Samory Mashela st., 1, Moscow, Russia, 117997
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Martins LAC, Queiroz PM, Nejaim Y, Vasconcelos KDF, Groppo FC, Haiter-Neto F. Evaluation of metal artefacts for two CBCT devices with a new dental arch phantom. Dentomaxillofac Radiol 2020; 49:20190385. [PMID: 32155087 DOI: 10.1259/dmfr.20190385] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVES To create a new phantom design to evaluate the real impact of artefacts caused by titanium on bone structures in cone beam CT images considering different positions and quantity of metals in the dental arch, with and without metal artefact reduction (MAR). METHODS A three cylindrical polymethyl methacrylate (PMMA) plate phantom was designed containing eight perforations arranged to simulate the lower dental arch in the intermediate plate. Three titanium cylinders were positioned in different locations and quantities to test different clinical conditions and to quantify the impact of the metal artefact around five bone cylinders. Scans were carried out in seven different protocols (Control, A-F) in two cone beam CT devices (OP300 Maxio and Picasso Trio). Eight regions of interest around each cortical and trabecular bone were used to measure the grey value standard deviation corresponding the artefact expression in the Image J software. Both the artefact expression and the MAR effect were assessed using the Wilcoxon, Friedman (Dunn) and Kruskal-Wallis tests (significance level of 5%). RESULTS For both devices, MAR was statistically efficient only for the protocols E, and F. Protocol F (three metals on the adjacent area of the analysis region) showed higher artefact expression when compared to the others. CONCLUSION In conclusion, the new phantom design allowed the quantification of the metal artefact expression caused by titanium. The metal artefact expression is higher when more metal objects are positioned in the adjacent bone structures. MAR may not be effective to reduce artefact expression on the adjacencies of those objects for the devices studied.
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Affiliation(s)
- Luciano Augusto Cano Martins
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Polyane Mazucatto Queiroz
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Yuri Nejaim
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Karla de Faria Vasconcelos
- Department of Imaging & Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Francisco Carlos Groppo
- Department of Physiological Sciences, Division of Pharmacology, Piracicaba Dental School, University of Campinas (UNICAMP), Campinas, Brazil
| | - Francisco Haiter-Neto
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo, Brazil
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Nori J, Gill MK, Vignoli C, Bicchierai G, De Benedetto D, Di Naro F, Vanzi E, Boeri C, Miele V. Artefacts in contrast enhanced digital mammography: how can they affect diagnostic image quality and confuse clinical diagnosis? Insights Imaging 2020; 11:16. [PMID: 32034578 PMCID: PMC7007474 DOI: 10.1186/s13244-019-0811-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 10/25/2019] [Indexed: 11/21/2022] Open
Abstract
Contrast-enhanced digital mammography (CEDM) is a diagnostic tool for breast cancer detection. Artefacts are observed in about 10% of CEDM examinations. Understanding CEDM artefacts is important to prevent diagnostic misinterpretation. In this article, we have described the artefacts that we have commonly encountered in clinical practice; we hope to ease the recognition and help troubleshoot solutions to prevent or minimise them.
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Affiliation(s)
- Jacopo Nori
- Diagnostic Senology Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | | | - Chiara Vignoli
- Diagnostic Senology Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy.
| | - Giulia Bicchierai
- Diagnostic Senology Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Diego De Benedetto
- Diagnostic Senology Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Federica Di Naro
- Diagnostic Senology Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Ermanno Vanzi
- Diagnostic Senology Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Cecilia Boeri
- Diagnostic Senology Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Vittorio Miele
- Department of Radiology, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
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Osman SOS, Russell E, King RB, Crowther K, Jain S, McGrath C, Hounsell AR, Prise KM, McGarry CK. Fiducial markers visibility and artefacts in prostate cancer radiotherapy multi-modality imaging. Radiat Oncol 2019; 14:237. [PMID: 31878967 PMCID: PMC6933910 DOI: 10.1186/s13014-019-1447-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 12/15/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND In this study, a novel pelvic phantom was developed and used to assess the visibility and presence of artefacts from different types of commercial fiducial markers (FMs) on multi-modality imaging relevant to prostate cancer. METHODS AND MATERIALS The phantom was designed with 3D printed hollow cubes in the centre. These cubes were filled with gel to mimic the prostate gland and two parallel PVC rods were used to mimic bones in the pelvic region. Each cube was filled with gelatine and three unique FMs were positioned with a clinically-relevant spatial distribution. The FMs investigated were; Gold Marker (GM) CIVCO, GM RiverPoint, GM Gold Anchor (GA) line and ball shape, and polymer marker (PM) from CIVCO. The phantom was scanned using several imaging modalities typically used to image prostate cancer patients; MRI, CT, CBCT, planar kV-pair, ExacTrac, 6MV, 2.5MV and integrated EPID imaging. The visibility of the markers and any observed artefacts in the phantom were compared to in-vivo scans of prostate cancer patients with FMs. RESULTS All GMs were visible in volumetric scans, however, they also had the most visible artefacts on CT and CBCT scans, with the magnitude of artefacts increasing with FM size. PM FMs had the least visible artefacts in volumetric scans but they were not visible on portal images and had poor visibility on lateral kV images. The smallest diameter GMs (GA) were the most difficult GMs to identify on lateral kV images. CONCLUSION The choice between different FMs is also dependent on the adopted IGRT strategy. PM was found to be superior to investigated gold markers in the most commonly used modalities in the management of prostate cancer; CT, CBCT and MRI imaging.
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Affiliation(s)
- Sarah O. S. Osman
- Centre of Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, Northern Ireland BT7 1NN UK
- Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
| | - Emily Russell
- Centre of Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, Northern Ireland BT7 1NN UK
| | - Raymond B. King
- Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
| | - Karen Crowther
- Radiotherapy Department, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
| | - Suneil Jain
- Centre of Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, Northern Ireland BT7 1NN UK
- Clinical Oncology, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
| | - Cormac McGrath
- Radiological Sciences and Imaging, Belfast Health and Social Care Trust, Forster Green Hospital, Belfast, UK
| | - Alan R. Hounsell
- Centre of Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, Northern Ireland BT7 1NN UK
- Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
| | - Kevin M. Prise
- Centre of Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, Northern Ireland BT7 1NN UK
| | - Conor K. McGarry
- Centre of Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, Northern Ireland BT7 1NN UK
- Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
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48
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Cammarota G, Verdina F, Santangelo E, Lauro G, Boniolo E, Tarquini R, Spinelli E, Zanoni M, Garofalo E, Bruni A, Pesenti A, Della Corte F, Navalesi P, Vaschetto R, Mauri T. Oesophageal balloon calibration during pressure support ventilation: a proof of concept study. J Clin Monit Comput 2019; 34:1223-1231. [PMID: 31792760 DOI: 10.1007/s10877-019-00436-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 11/28/2019] [Indexed: 01/20/2023]
Abstract
Oesophageal balloon calibration improves the oesophageal pressure (Pes) assessment during invasive controlled mechanical ventilation. The primary aim of the present investigation was to ascertain the feasibility of oesophageal balloon calibration during pressure support ventilation (PSV). Secondarily, the calibrated Pes (Pescal) was compared to uncalibrated one acquired at 4 ml-filling volume (PesV4), as per manufacturer recommendation. After a naso-gastric tube equipped with oesophageal balloon was correctly positioned in 21 adult patients undergoing invasive volume-controlled ventilation (VCV) for acute hypoxemic respiratory failure, the balloon was progressively inflated, applying a series of end-inspiratory and end-expiratory holds at each filling volume during VCV and PSV. Upon optimal balloon filling volume (Vbest) was identified, Pescal was computed by correcting the Pes measured at Vbest for the oesophageal wall pressure elicited at same filling volume. Finally, end-expiratory and end-inspiratory PesV4 were recorded too. A total of 42 calibrations, 21 per ventilatory mode, were performed. Vbest was 1.9 ± 1.6 ml in VCV and 1.7 ± 1.6 ml in PSV (p = 0.5217). PesV4 was overestimated compared to Pescal at end-expiration and end-inspiration (p <0.0001 for all comparisons) in both VCV (13.4 ± 3.4 cmH2O and 15.4 ± 3 cmH2O vs. 8.5 ± 2.9 cmH2O and 11.4 ± 3 cmH2O) and PSV (14.7 ± 4.2 cmH2O and 17 ± 3.9 cmH2O vs. 8.9 ± 3.4 cmH2O and 12.4 ± 3.9 cmH2O). In PSV, oesophageal balloon calibration is feasible and allows to obtain a reliable Pes assessment compared to uncalibrated approach.
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Affiliation(s)
- Gianmaria Cammarota
- Anaesthesia and General Intensive Care, "Maggiore della Carità" University Hospital, Corso Mazzini18, 28100, Novara, Italy.
| | - Federico Verdina
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Erminio Santangelo
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Gianluigi Lauro
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Ester Boniolo
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Riccardo Tarquini
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Elena Spinelli
- Department of Anaesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Marta Zanoni
- Anaesthesia and General Intensive Care, "Maggiore della Carità" University Hospital, Corso Mazzini18, 28100, Novara, Italy
| | - Eugenio Garofalo
- Department of Medical and Surgical Science, Università Magna Greacia, Catanzaro, Italy
| | - Andrea Bruni
- Department of Medical and Surgical Science, Università Magna Greacia, Catanzaro, Italy
| | - Antonio Pesenti
- Department of Anaesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Francesco Della Corte
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Paolo Navalesi
- Department of Medical and Surgical Science, Università Magna Greacia, Catanzaro, Italy
| | - Rosanna Vaschetto
- Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Tommaso Mauri
- Department of Anaesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
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49
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Moeyersons J, Smets E, Morales J, Villa A, De Raedt W, Testelmans D, Buyse B, Van Hoof C, Willems R, Van Huffel S, Varon C. Artefact detection and quality assessment of ambulatory ECG signals. Comput Methods Programs Biomed 2019; 182:105050. [PMID: 31473442 PMCID: PMC6891233 DOI: 10.1016/j.cmpb.2019.105050] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/23/2019] [Accepted: 08/23/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND AND OBJECTIVES The presence of noise sources could reduce the diagnostic capability of the ECG signal and result in inappropriate treatment decisions. To mitigate this problem, automated algorithms to detect artefacts and quantify the quality of the recorded signal are needed. In this study we present an automated method for the detection of artefacts and quantification of the signal quality. The suggested methodology extracts descriptive features from the autocorrelation function and feeds these to a RUSBoost classifier. The posterior probability of the clean class is used to create a continuous signal quality assessment index. Firstly, the robustness of the proposed algorithm is investigated and secondly, the novel signal quality assessment index is evaluated. METHODS Data were used from three different studies: a Sleep study, the PhysioNet 2017 Challenge and a Stress study. Binary labels, clean or contaminated, were available from different annotators with experience in ECG analysis. Two types of realistic ECG noise from the MIT-BIH Noise Stress Test Database (NSTDB) were added to the Sleep study to test the quality index. Firstly, the model was trained on the Sleep dataset and subsequently tested on a subset of the other two datasets. Secondly, all recording conditions were taken into account by training the model on a subset derived from the three datasets. Lastly, the posterior probabilities of the model for the different levels of agreement between the annotators were compared. RESULTS AUC values between 0.988 and 1.000 were obtained when training the model on the Sleep dataset. These results were further improved when training on the three datasets and thus taking all recording conditions into account. A Pearson correlation coefficient of 0.8131 was observed between the score of the clean class and the level of agreement. Additionally, significant quality decreases per noise level for both types of added noise were observed. CONCLUSIONS The main novelty of this study is the new approach to ECG signal quality assessment based on the posterior clean class probability of the classifier.
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Affiliation(s)
| | | | - John Morales
- Department of Electrical Engineering, KU Leuven, B-3001 Leuven, Belgium.
| | - Amalia Villa
- Department of Electrical Engineering, KU Leuven, B-3001 Leuven, Belgium.
| | | | - Dries Testelmans
- Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, B-3001 Leuven, Belgium.
| | - Bertien Buyse
- Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, B-3001 Leuven, Belgium.
| | - Chris Van Hoof
- Department of Electrical Engineering, KU Leuven, B-3001 Leuven, Belgium; imec, B-3001 Leuven, Belgium.
| | - Rik Willems
- Department of Cardiovascular Sciences, KU Leuven, B-3001 Leuven, Belgium.
| | - Sabine Van Huffel
- Department of Electrical Engineering, KU Leuven, B-3001 Leuven, Belgium.
| | - Carolina Varon
- Department of Electrical Engineering, KU Leuven, B-3001 Leuven, Belgium.
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50
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Leidenberger T, Winkel A, Philipp C, Rump J, De Bucourt M, Böning G, Teichgräber U, Streitparth F. MR-Guided Percutaneous Intradiscal Thermotherapy (MRgPIT): Evaluation of a New Technique for the Treatment of Degenerative Disc Disease in Cadaveric Lumbar Spine. Cardiovasc Intervent Radiol 2020; 43:505-13. [PMID: 31773189 DOI: 10.1007/s00270-019-02382-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 11/19/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE Evaluation of MR feasibility and real-time control of an innovative thermoablative applicator for intradiscal thermotherapy and histological analysis of laser annuloplasty in human ex vivo intervertebral discs. MATERIALS AND METHODS We evaluated a new MR-compatible applicator system for MR-guided percutaneous intradiscal thermotherapy (MRgPIT) in an open 1.0-T MRI-system. Needle artefacts and contrast-to-noise ratios (CNR) of six interactive sequences (PD-, T1-, T2w TSE, T1-, T2w GRE, bSSFP) with varying echo-times (TE) and needle orientations to the main magnetic field (B0) were analysed. Additionally, five laser protocols (Nd: YAG Laser, 2-6 W) were assessed in 50 ex vivo human intervertebral discs with subsequent histological evaluation. RESULTS In vitro, we found optimal needle artefacts of 1.5-5 mm for the PDw TSE sequence in all angles of the applicator system to B0. A TE of 20 ms yielded the best CNR. Ex vivo, ablating with 5 W induced histological denaturation of collagen at the dorsal annulus, correlating with a rise in temperature to at least 60 °C. The MRgPIT procedure was feasible with an average intervention time of 17.1 ± 5.7 min. CONCLUSION Real-time MR-guided positioning of the MRgPIT-applicator in cadaveric intervertebral disc is feasible and precise using fast TSE sequence designs. Laser-induced denaturation of collagen in the dorsal annulus fibrosus proved to be accurate.
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