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Vandewinckele L, Reynders T, Weltens C, Maes F, Crijns W. Deep learning based MLC aperture and monitor unit prediction as a warm start for breast VMAT optimisation. Phys Med Biol 2023; 68:225013. [PMID: 37903442 DOI: 10.1088/1361-6560/ad07f6] [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: 06/30/2023] [Accepted: 10/30/2023] [Indexed: 11/01/2023]
Abstract
Objective. Automated treatment planning today is focussed on non-exact, two-step procedures. Firstly, dose-volume histograms (DVHs) or 3D dose distributions are predicted from the patient anatomy. Secondly, these are converted in multi-leaf collimator (MLC) apertures and monitor units (MUs) using a generic optimisation to obtain the final treatment plan. In contrast, we present a method to predict volumetric modulated arc therapy (VMAT) MLC apertures and MUs directly from patient anatomy using deep learning. The predicted plan is then provided as initialisation to the optimiser for fine-tuning.Approach. 148 patients (training: 101; validation: 23; test: 24), treated for right breast cancer, are replanned to obtain a homogeneous database of 3-arc VMAT plans (PTVBreast: 45.57 Gy; PTVBoost: 55.86 Gy) according to the clinical protocol, using RapidPlanTMwith automatic optimisation and extended convergence mode (clinical workflow). Projections of the CT and contours are created along the beam's eye view of all control points and given as input to a U-net type convolutional neural networks (CNN). The output are the MLC aperture and MU for all control points, from which a DICOM RTplan is built. This is imported and further optimised in the treatment planning system using automatic optimisation without convergence mode, with clinical PTV objectives and organs-at-risk (OAR) objectives based on the DVHs calculated from the imported plan (CNN workflow).Main results. Mean dose differences between the clinical and CNN workflow over the test set are 0.2 ± 0.5 Gy atD95%and 0.6 ± 0.4 Gy atD0.035ccof PTVBreastand -0.4 ± 0.3 Gy atD95%and 0.7 ± 0.3 Gy atD0.035ccof PTVBoost. For the OAR, they are -0.2 ± 0.2 Gy forDmean,heartand 0.04 ± 0.8 Gy forDmean,ipsilateral lung. The mean computation time is 60 and 25 min respectively.Significance. VMAT optimisation can be initialised by MLC apertures and MUs, directly predicted from patient anatomy using a CNN, reducing planning time with more than half while maintaining clinically acceptable plans. This procedure puts the planner in a supervising role over an AI-based treatment planning workflow.
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Affiliation(s)
- L Vandewinckele
- Department of Oncology, Laboratory of Experimental Radiotherapy, KU Leuven, Belgium
- Department of Radiation Oncology, UZ Leuven, Belgium
| | - T Reynders
- Department of Radiation Oncology, UZ Leuven, Belgium
| | - C Weltens
- Department of Oncology, Laboratory of Experimental Radiotherapy, KU Leuven, Belgium
- Department of Radiation Oncology, UZ Leuven, Belgium
| | - F Maes
- Department ESAT/PSI, KU Leuven, Belgium
- Medical Imaging Research Center, UZ Leuven, Belgium
| | - W Crijns
- Department of Oncology, Laboratory of Experimental Radiotherapy, KU Leuven, Belgium
- Department of Radiation Oncology, UZ Leuven, Belgium
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Azizi M, Mahfoud F, Weber MA, Sharp ASP, Schmieder RE, Lurz P, Lobo MD, Fisher NDL, Daemen J, Bloch MJ, Basile J, Sanghvi K, Saxena M, Gosse P, Jenkins JS, Levy T, Persu A, Kably B, Claude L, Reeve-Stoffer H, McClure C, Kirtane AJ, Mullin C, Thackeray L, Chertow G, Kahan T, Dauerman H, Ullery S, Abbott JD, Loening A, Zagoria R, Costello J, Krathan C, Lewis L, McElvarr A, Reilly J, Cash M, Williams S, Jarvis M, Fong P, Laffer C, Gainer J, Robbins M, Crook S, Maddel S, Hsi D, Martin S, Portnay E, Ducey M, Rose S, DelMastro E, Bangalore S, Williams S, Cabos S, Rodriguez Alvarez C, Todoran T, Powers E, Hodskins E, Paladugu V, Tecklenburg A, Devireddy C, Lea J, Wells B, Fiebach A, Merlin C, Rader F, Dohad S, Kim HM, Rashid M, Abraham J, Owan T, Abraham A, Lavasani I, Neilson H, Calhoun D, McElderry T, Maddox W, Oparil S, Kinder S, Radhakrishnan J, Batres C, Edwards S, Garasic J, Drachman D, Zusman R, Rosenfield K, Do D, Khuddus M, Zentko S, O'Meara J, Barb I, Foster A, Boyette A, Wang Y, Jay D, Skeik N, Schwartz R, Peterson R, Goldman JA, Goldman J, Ledley G, Katof N, Potluri S, Biedermann S, Ward J, White M, Mauri L, Sobieszczky P, Smith A, Aseltine L, Stouffer R, Hinderliter A, Pauley E, Wade T, Zidar D, Shishehbor M, Effron B, Costa M, Semenec T, Roongsritong C, Nelson P, Neumann B, Cohen D, Giri J, Neubauer R, Vo T, Chugh AR, Huang PH, Jose P, Flack J, Fishman R, Jones M, Adams T, Bajzer C, Mathur A, Jain A, Balawon A, Zongo O, Bent C, Beckett D, Lakeman N, Kennard S, D’Souza RJ, Statton S, Wilkes L, Anning C, Sayer J, Iyer SG, Robinson N, Sevillano A, Ocampo M, Gerber R, Faris M, Marshall AJ, Sinclair J, Pepper H, Davies J, Chapman N, Burak P, Carvelli P, Jadhav S, Quinn J, Rump LC, Stegbauer J, Schimmöller L, Potthoff S, Schmid C, Roeder S, Weil J, Hafer L, Agdirlioglu T, Köllner T, Böhm M, Ewen S, Kulenthiran S, Wachter A, Koch C, Fengler K, Rommel KP, Trautmann K, Petzold M, Ott C, Schmid A, Uder M, Heinritz U, Fröhlich-Endres K, Genth-Zotz S, Kämpfner D, Grawe A, Höhne J, Kaesberger B, von zur Mühlen C, Wolf D, Welzel M, Heinrichs G, Trabitzsch B, Cremer A, Trillaud H, Papadopoulos P, Maire F, Gaudissard J, Sapoval M, Livrozet M, Lorthioir A, Amar L, Paquet V, Pathak A, Honton B, Cottin M, Petit F, Lantelme P, Berge C, Courand PY, Langevin F, Delsart P, Longere B, Ledieu G, Pontana F, Sommeville C, Bertrand F, Feyz L, Zeijen V, Ruiter A, Huysken E, Blankestijn P, Voskuil M, Rittersma Z, Dolmans H, Kroon A, van Zwam W, Vranken J, de Haan. C, Renkin J, Maes F, Beauloye C, Lengelé JP, Huyberechts D, Bouvie A, Witkowski A, Januszewicz A, Kądziela J, Prejbisj A, Hering D, Ciecwierz D, Jaguszewski MJ, Owczuk R. Effects of Renal Denervation vs Sham in Resistant Hypertension After Medication Escalation: Prespecified Analysis at 6 Months of the RADIANCE-HTN TRIO Randomized Clinical Trial. JAMA Cardiol 2022; 7:1244-1252. [PMID: 36350593 PMCID: PMC9647563 DOI: 10.1001/jamacardio.2022.3904] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Importance Although early trials of endovascular renal denervation (RDN) for patients with resistant hypertension (RHTN) reported inconsistent results, ultrasound RDN (uRDN) was found to decrease blood pressure (BP) vs sham at 2 months in patients with RHTN taking stable background medications in the Study of the ReCor Medical Paradise System in Clinical Hypertension (RADIANCE-HTN TRIO) trial. Objectives To report the prespecified analysis of the persistence of the BP effects and safety of uRDN vs sham at 6 months in conjunction with escalating antihypertensive medications. Design, Setting, and Participants This randomized, sham-controlled, clinical trial with outcome assessors and patients blinded to treatment assignment, enrolled patients from March 11, 2016, to March 13, 2020. This was an international, multicenter study conducted in the US and Europe. Participants with daytime ambulatory BP of 135/85 mm Hg or higher after 4 weeks of single-pill triple-combination treatment (angiotensin-receptor blocker, calcium channel blocker, and thiazide diuretic) with estimated glomerular filtration rate (eGFR) of 40 mL/min/1.73 m2 or greater were randomly assigned to uRDN or sham with medications unchanged through 2 months. From 2 to 5 months, if monthly home BP was 135/85 mm Hg or higher, standardized stepped-care antihypertensive treatment starting with aldosterone antagonists was initiated under blinding to treatment assignment. Interventions uRDN vs sham procedure in conjunction with added medications to target BP control. Main Outcomes and Measures Six-month change in medications, change in daytime ambulatory systolic BP, change in home systolic BP adjusted for baseline BP and medications, and safety. Results A total of 65 of 69 participants in the uRDN group and 64 of 67 participants in the sham group (mean [SD] age, 52.4 [8.3] years; 104 male [80.6%]) with a mean (SD) eGFR of 81.5 (22.8) mL/min/1.73 m2 had 6-month daytime ambulatory BP measurements. Fewer medications were added in the uRDN group (mean [SD], 0.7 [1.0] medications) vs sham (mean [SD], 1.1 [1.1] medications; P = .045) and fewer patients in the uRDN group received aldosterone antagonists at 6 months (26 of 65 [40.0%] vs 39 of 64 [60.9%]; P = .02). Despite less intensive standardized stepped-care antihypertensive treatment, mean (SD) daytime ambulatory BP at 6 months was 138.3 (15.1) mm Hg with uRDN vs 139.0 (14.3) mm Hg with sham (additional decreases of -2.4 [16.6] vs -7.0 [16.7] mm Hg from month 2, respectively), whereas home SBP was lowered to a greater extent with uRDN by 4.3 mm Hg (95% CI, 0.5-8.1 mm Hg; P = .03) in a mixed model adjusting for baseline and number of medications. Adverse events were infrequent and similar between groups. Conclusions and Relevance In this study, in patients with RHTN initially randomly assigned to uRDN or a sham procedure and who had persistent elevation of BP at 2 months after the procedure, standardized stepped-care antihypertensive treatment escalation resulted in similar BP reduction in both groups at 6 months, with fewer additional medications required in the uRDN group. Trial Registration ClinicalTrials.gov Identifier: NCT02649426.
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Affiliation(s)
- Michel Azizi
- Université Paris Cité, F-75006 Paris, France,Assistance Publique–Hôpitaux de Paris, Hôpital Européen Georges-Pompidou, Hypertension Department and DMU CARTE, F-75015 Paris, France,INSERM, CIC1418, F-75015 Paris, France
| | - Felix Mahfoud
- Klinik für Innere Medizin III, Saarland University Hospital, Homburg/Saar, Germany,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge
| | - Michael A. Weber
- Division of Cardiovascular Medicine, State University of New York, Downstate Medical Center, New York
| | - Andrew S. P. Sharp
- University Hospital of Wales, Cardiff and University of Exeter, Exeter, United Kingdom
| | - Roland E. Schmieder
- Nephrology and Hypertension, University Hospital Erlangen, Friedrich Alexander University, Erlangen, Germany
| | - Philipp Lurz
- Heart Center Leipzig, University of Leipzig, Leipzig, Germany
| | - Melvin D. Lobo
- Barts NIHR Biomedical Research Centre, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | | | - Joost Daemen
- Erasmus MC, University Medical Center Rotterdam, Department of Cardiology, Rotterdam, the Netherlands
| | - Michael J. Bloch
- Department of Medicine, University of Nevada School of Medicine, Vascular Care, Renown Institute of Heart and Vascular Health, Reno
| | - Jan Basile
- Division of Cardiovascular Medicine, Medical University of South Carolina, Ralph H. Johnson VA Medical Center, Charleston
| | | | - Manish Saxena
- Barts NIHR Biomedical Research Centre, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | | | | | - Terry Levy
- Royal Bournemouth Hospital, Dorset, United Kingdom
| | - Alexandre Persu
- Division of Cardiology, Cliniques Universitaires Saint-Luc and Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Benjamin Kably
- Assistance Publique–Hôpitaux de Paris, Hôpital Européen Georges-Pompidou, Department of Pharmacology, Paris, France
| | | | | | | | - Ajay J. Kirtane
- Columbia University Medical Center/New York-Presbyterian Hospital and the Cardiovascular Research Foundation, New York
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Danny Do
- for the RADIANCE-HTN Investigators
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Jay Giri
- for the RADIANCE-HTN Investigators
| | | | - Thu Vo
- for the RADIANCE-HTN Investigators
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De Wel B, Huysmans L, Peeters R, Goosens V, Ghysels S, Byloos K, Putzeys G, D'Hondt A, De Bleecker J, Dupont P, Maes F, Claeys K. P.176 Evaluation of thigh muscle fat fraction with quantitative MRI in 24 adult LGMDR12 patients over 2 years of follow-up. Neuromuscul Disord 2022. [DOI: 10.1016/j.nmd.2022.07.314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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De Wel B, Huysmans L, Maes F, Dupont P, Claeys K. P.177 Analysis of the proximo-distal gradients of fat replacement along the length of thigh muscles in LGMDR12 patients. Neuromuscul Disord 2022. [DOI: 10.1016/j.nmd.2022.07.315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Maes F. SP-0679 U-Net for dummies. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)04003-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bollen H, Nuyts S, Willems S, Maes F. MO-0886 Automatic delineation of head and neck gross tumor volume using multimodal information. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)02452-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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De Wel B, Huysmans L, Peeters R, D'Hondt A, Goosens V, Ghysels S, Byloos K, Putzeys G, De Bleecker J, Maes F, Dupont P, Claeys K. LGMD. Neuromuscul Disord 2021. [DOI: 10.1016/j.nmd.2021.07.214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Vandewinckele L, Willems S, Lambrecht M, Maes F, Crijns W. PD-0819 Dose mimicking by deep learning based fluence prediction: one model for different class solutions. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)07098-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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van der Veen J, Gulyban A, Willems S, Maes F, Nuyts S. Interobserver variability in organ at risk delineation in head and neck cancer. Radiat Oncol 2021; 16:120. [PMID: 34183040 PMCID: PMC8240214 DOI: 10.1186/s13014-020-01677-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [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: 07/01/2020] [Accepted: 09/24/2020] [Indexed: 11/25/2022] Open
Abstract
Background In radiotherapy inaccuracy in organ at risk (OAR) delineation can impact treatment plan optimisation and treatment plan evaluation. Brouwer et al. showed significant interobserver variability (IOV) in OAR delineation in head and neck cancer (HNC) and published international consensus guidelines (ICG) for OAR delineation in 2015. The aim of our study was to evaluate IOV in the presence of these guidelines. Methods HNC radiation oncologists (RO) from each Belgian radiotherapy centre were invited to complete a survey and submit contours for 5 HNC cases. Reference contours (OARref) were obtained by a clinically validated artificial intelligence-tool trained using ICG. Dice similarity coefficients (DSC), mean surface distance (MSD) and 95% Hausdorff distances (HD95) were used for comparison. Results Fourteen of twenty-two RO (64%) completed the survey and submitted delineations. Thirteen (93%) confirmed the use of delineation guidelines, of which six (43%) used the ICG. The OARs whose delineations agreed best with the OARref were mandible [median DSC 0.9, range (0.8–0.9); median MSD 1.1 mm, range (0.8–8.3), median HD95 3.4 mm, range (1.5–38.7)], brainstem [median DSC 0.9 (0.6–0.9); median MSD 1.5 mm (1.1–4.0), median HD95 4.0 mm (2.3–15.0)], submandibular glands [median DSC 0.8 (0.5–0.9); median MSD 1.2 mm (0.9–2.5), median HD95 3.1 mm (1.8–12.2)] and parotids [median DSC 0.9 (0.6–0.9); median MSD 1.9 mm (1.2–4.2), median HD95 5.1 mm (3.1–19.2)]. Oral cavity, cochleas, PCMs, supraglottic larynx and glottic area showed more variation. RO who used the consensus guidelines showed significantly less IOV (p = 0.008). Conclusions Although ICG for delineation of OARs in HNC exist, they are only implemented by about half of RO participating in this study, which partly explains the delineation variability. However, this study highlights that guidelines alone do not suffice to eliminate IOV and that more effort needs to be done to accomplish further treatment standardisation, for example with artificial intelligence.
Supplementary information Supplementary information accompanies this paper at 10.1186/s13014-020-01677-2.
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Affiliation(s)
- J van der Veen
- Department of Oncology, Radiation-Oncology, University of Leuven, University Hospitals Leuven, 3000, Leuven, KU, Belgium
| | - A Gulyban
- Department of Medical Physics, Jules Bordet Institute, Brussels, Belgium.
| | - S Willems
- Department ESAT, Processing Speech and Images (PSI), Medical Imaging Research Center, KU Leuven, University Hospitals Leuven, 3000, Leuven, Belgium
| | - F Maes
- Department ESAT, Processing Speech and Images (PSI), Medical Imaging Research Center, KU Leuven, University Hospitals Leuven, 3000, Leuven, Belgium
| | - S Nuyts
- Department of Oncology, Radiation-Oncology, University of Leuven, University Hospitals Leuven, 3000, Leuven, KU, Belgium.
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Levina N, Maes F, Sabbe BGC. [Psychosis due to idiopathic basal ganglia calcification]. Tijdschr Psychiatr 2019; 61:48-52. [PMID: 30640406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Idiopathic basal ganglia calcification is a rare neuropathological syndrome characterised by symmetrical and bilateral calcifications found primarily in the basal ganglia. Psychosis is describedas an acute presentation of idiopathic ganglia calcification. We describe the development of psychosis in a 48-year-old man, initially hospitalised on the neurology ward due to syncope. A ct scan of the brain showed bilateral, symmetrical calcification of the basal ganglia and nucleus dentatus. Laboratory research excluded other pathological disorders. The patient was referred to a psychiatric ward, where the administration of risperidone led to alleviation of his mental state. This case report underlines the importance of an accurate, comprehensive differential diagnosis and the associated significance of neuroimaging.
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Maes F. SP-0448: Radiomics – How does artificial intelligence shape the future of medical imaging? Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)30758-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Sauwen N, Acou M, Van Cauter S, Sima DM, Veraart J, Maes F, Himmelreich U, Achten E, Van Huffel S. Comparison of unsupervised classification methods for brain tumor segmentation using multi-parametric MRI. Neuroimage Clin 2016; 12:753-764. [PMID: 27812502 PMCID: PMC5079350 DOI: 10.1016/j.nicl.2016.09.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [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: 07/07/2016] [Revised: 09/27/2016] [Accepted: 09/29/2016] [Indexed: 12/03/2022]
Abstract
Tumor segmentation is a particularly challenging task in high-grade gliomas (HGGs), as they are among the most heterogeneous tumors in oncology. An accurate delineation of the lesion and its main subcomponents contributes to optimal treatment planning, prognosis and follow-up. Conventional MRI (cMRI) is the imaging modality of choice for manual segmentation, and is also considered in the vast majority of automated segmentation studies. Advanced MRI modalities such as perfusion-weighted imaging (PWI), diffusion-weighted imaging (DWI) and magnetic resonance spectroscopic imaging (MRSI) have already shown their added value in tumor tissue characterization, hence there have been recent suggestions of combining different MRI modalities into a multi-parametric MRI (MP-MRI) approach for brain tumor segmentation. In this paper, we compare the performance of several unsupervised classification methods for HGG segmentation based on MP-MRI data including cMRI, DWI, MRSI and PWI. Two independent MP-MRI datasets with a different acquisition protocol were available from different hospitals. We demonstrate that a hierarchical non-negative matrix factorization variant which was previously introduced for MP-MRI tumor segmentation gives the best performance in terms of mean Dice-scores for the pathologic tissue classes on both datasets. Unsupervised classification algorithms are applied for brain tumor segmentation on multi-parametric MRI datasets. Reported mean Dice-scores are in the range of state-of-the-art segmentation algorithms. Hierarchical NMF obtained the best segmentation results in terms of mean Dice-scores for most of the tissue classes.
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Key Words
- 1H MRSI, proton magnetic resonance spectroscopic imaging
- ADC, apparent diffusion coefficient
- Cho, total choline
- Clustering
- Cre, total creatine
- DKI, diffusion kurtosis imaging
- DSC-MRI, dynamic susceptibility-weighted contrast-enhanced magnetic resonance imaging
- DTI, diffusion tensor imaging
- DWI, diffusion-weighted imaging
- FA, fractional anisotropy
- FCM, fuzzy C-means clustering
- FLAIR, fluid-attenuated inversion recovery
- GBM, glioblastoma multiforme
- GMM, Gaussian mixture modelling
- Glioma
- Glx, glutamine + glutamate
- Gly, glycine
- HALS, hierarchical alternating least squares
- HGG, high-grade glioma
- LGG, low-grade glioma
- Lac, lactate
- Lip, lipids
- MD, mean diffusivity
- MK, mean kurtosis
- MP-MRI, multi-parametric magnetic resonance imaging
- Multi-parametric MRI
- NAA, N-acetyl-aspartate
- NMF, non-negative matrix factorization
- NNLS, non-negative linear least-squares
- Non-negative matrix factorization
- PWI, perfusion-weighted imaging
- ROI, region of interest
- SC, spectral clustering
- SPA, successive projection algorithm
- Segmentation
- T1c, contrast-enhanced T1
- UZ Gent, University hospital of Ghent
- UZ Leuven, University hospitals of Leuven
- Unsupervised classification
- cMRI, conventional magnetic resonance imaging
- hNMF, hierarchical non-negative matrix factorization
- mI, myo-inositol
- rCBV, relative cerebral blood volume
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Affiliation(s)
- N Sauwen
- KU Leuven, Department of Electrical Engineering (ESAT), STADIUS Centre for Dynamical Systems, Signal Processing and Data Analytics, Leuven, Belgium; iMinds, Department of Medical Information Technologies, Belgium
| | - M Acou
- Ghent University Hospital, Department of Radiology, Ghent, Belgium
| | - S Van Cauter
- University Hospitals of Leuven, Department of Radiology, Leuven, Belgium; Ziekenhuizen Oost-Limburg, Department of Radiology, Leuven, Belgium
| | - D M Sima
- KU Leuven, Department of Electrical Engineering (ESAT), STADIUS Centre for Dynamical Systems, Signal Processing and Data Analytics, Leuven, Belgium; iMinds, Department of Medical Information Technologies, Belgium
| | - J Veraart
- University of Antwerp, iMinds Vision Lab, Department of Physics, Antwerp, Belgium
| | - F Maes
- KU Leuven, Department of Electrical Engineering (ESAT), PSI Centre for Processing Speech and Images, Leuven, Belgium
| | - U Himmelreich
- KU Leuven, Biomedical MRI/MoSAIC, Department of Imaging and Pathology, Leuven, Belgium
| | - E Achten
- Ghent University Hospital, Department of Radiology, Ghent, Belgium
| | - S Van Huffel
- KU Leuven, Department of Electrical Engineering (ESAT), STADIUS Centre for Dynamical Systems, Signal Processing and Data Analytics, Leuven, Belgium; iMinds, Department of Medical Information Technologies, Belgium
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Callens M, Crijns W, Simons V, De Wolf I, Depuydt T, Maes F, Haustermans K, D'hooge J, D'Agostino E, Wevers M, Pfeiffer H, Van Den Abeele K. A spectroscopic study of the chromatic properties of GafChromic™EBT3 films. Med Phys 2016; 43:1156-66. [DOI: 10.1118/1.4941312] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- M. Callens
- Wave Propagation and Signal Processing, KU Leuven–KULAK, Kortrijk 8500, Belgium
| | - W. Crijns
- Department of Radiation Oncology, University Hospitals Leuven, Leuven 3000, Belgium
| | - V. Simons
- imec, Kapeldreef 75, Leuven 3001, Belgium
| | - I. De Wolf
- imec, Kapeldreef 75, Leuven 3001, Belgium and Department of Materials Engineering, KU Leuven, Leuven 3001, Belgium
| | - T. Depuydt
- Department of Radiation Oncology, University Hospitals Leuven, Leuven 3000, Belgium
| | - F. Maes
- Department of Electrical Engineering, ESAT/PSI, KU Leuven, Leuven 3001, Belgium
| | - K. Haustermans
- Department of Radiation Oncology, University Hospitals Leuven, Leuven 3000, Belgium
| | - J. D'hooge
- Department of Cardiovascular Sciences, KU Leuven, Leuven 3000, Belgium
| | | | - M. Wevers
- Department of Materials Engineering, KU Leuven, Leuven 3001, Belgium
| | - H. Pfeiffer
- Department of Materials Engineering, KU Leuven, Leuven 3001, Belgium
| | - K. Van Den Abeele
- Wave Propagation and Signal Processing, KU Leuven–KULAK, Kortrijk 8500, Belgium
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Crijns W, Ramaekers S, Leblans P, Defraene G, Maes F, Haustermans K, Depuydt T. SU-E-T-497: Initial Characterization of a Novel 2D Computed Radiography (CR) Dosimeter for SBRT. Med Phys 2015. [DOI: 10.1118/1.4924859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Callens M, Crijns W, Simons V, De Wolf I, Depuydt T, Maes F, Haustermans K, D'hooge J, D'Agostino E, Pfeiffer H, Van Den Abeele K. SU-E-T-44: A Micro-Raman Spectroscopy Study of the Dose-Dependence of EBT3 GafChromicTM Films for Quantifying the Degree of Molecular Polymerization. Med Phys 2015. [DOI: 10.1118/1.4924405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Crijns W, Defraene G, Van Herck H, Depuydt T, Haustermans K, Maes F, Van den Heuvel F. PD-0462: Towards dosimetric tracking with adaptive VMAT? Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40458-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Bartzis J, Wolkoff P, Stranger M, Efthimiou G, Tolis EI, Maes F, Nørgaard AW, Ventura G, Kalimeri KK, Goelen E, Fernandes O. On organic emissions testing from indoor consumer products' use. J Hazard Mater 2015; 285:37-45. [PMID: 25462869 DOI: 10.1016/j.jhazmat.2014.11.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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: 09/04/2014] [Revised: 11/13/2014] [Accepted: 11/19/2014] [Indexed: 05/04/2023]
Abstract
A wide range of consumer and personal care products may, during their use, release significant amounts of volatile organic compounds (VOC) into the air. The identification and quantification of the emissions from such sources is typically performed in emission test chambers. A major question is to what degree the obtained emissions are reproducible and directly applicable to real situations. The present work attempts partly to address this question by comparison of selected VOC emissions in specific consumer products tested in chambers of various dimensions. The measurements were performed in three test chambers of different volumes (0.26-20 m(3)). The analytic performance of the laboratories was rigorously assessed prior to chamber testing. The results show emission variation for major VOC (terpenes); however, it remains in general, within the same order of magnitude for all tests. This variability does not seem to correlate with the chamber volume. It rather depends on the overall testing conditions. The present work is undertaken in the frame of EPHECT European Project.
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Affiliation(s)
- J Bartzis
- Environmental Technology Laboratory, Department of Mechanical Engineering, University of Western Macedonia, Sialvera & Bakola Str., 50100 Kozani, Greece.
| | - P Wolkoff
- National Research Centre for the Working Environment, Lersø Parkalle 105, DK-2100 Copenhagen, Denmark.
| | - M Stranger
- Environmental Risk and Health Unit, VITO, Boeretang 200, 2400 Mol, Belgium.
| | - G Efthimiou
- Environmental Technology Laboratory, Department of Mechanical Engineering, University of Western Macedonia, Sialvera & Bakola Str., 50100 Kozani, Greece.
| | - E I Tolis
- Environmental Technology Laboratory, Department of Mechanical Engineering, University of Western Macedonia, Sialvera & Bakola Str., 50100 Kozani, Greece.
| | - F Maes
- Environmental Risk and Health Unit, VITO, Boeretang 200, 2400 Mol, Belgium.
| | - A W Nørgaard
- National Research Centre for the Working Environment, Lersø Parkalle 105, DK-2100 Copenhagen, Denmark.
| | - G Ventura
- Institute of Mechanical Engineering, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal.
| | - K K Kalimeri
- Environmental Technology Laboratory, Department of Mechanical Engineering, University of Western Macedonia, Sialvera & Bakola Str., 50100 Kozani, Greece.
| | - E Goelen
- Environmental Risk and Health Unit, VITO, Boeretang 200, 2400 Mol, Belgium.
| | - O Fernandes
- Institute of Mechanical Engineering, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal.
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Maes F, Sabbe BGC, Luyten P, Beukeleirs T. [Measuring alexithymia in fibromyalgia: the need for a multimodal measurement method to replace the TAS-20]. Tijdschr Psychiatr 2015; 57:343-351. [PMID: 26028015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
BACKGROUND In an earlier publication that investigated alexithymia in fibromyalgia, we showed the Toronto Alexithymia Scale was the only instrument being used to measure alexithymia. AIM To find out which instruments are currently available for measuring alexithymia, to compare the psychometric properties of these instruments and to decide whether some of the test methods involved should be used to give extra value to alexithymia research. METHOD We conducted a systematic review of the literature in Medline/PubMed with a number of search terms. We selected articles relating to psychometric properties of the tests performed and decided whether they could be influenced by negative affect. RESULTS We found that 14 different instruments were used to measure alexithymia. From our evaluation we excluded tests which had weak psychometric properties or had been inadequately assessed. There remained three observation scales and two self-report questionnaires, which had been adequately validated and whose relative strengths and weaknesses were compared. CONCLUSION In view of these findings, we recommend that in studies of alexithymia in fibromyalgia a multimodal measurement method should be used rather than only the tas-20.
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Domingos J, Augustine D, Leeson P, Noble J, Doan HL, Boubrit L, Cheikh-Khalifa R, Laveau F, Djebbar M, Pousset F, Isnard R, Hammoudi N, Lisi M, Cameli M, Di Tommaso C, Curci V, Reccia R, Maccherini M, Henein MY, Mondillo S, Leitman M, Vered Z, Rashid H, Yalcin MU, Gurses KM, Kocyigit D, Evranos B, Yorgun H, Sahiner L, Kaya B, Aytemir K, Ozer N, Bertella E, Petulla' M, Baggiano A, Mushtaq S, Russo E, Gripari P, Innocenti E, Andreini D, Tondo C, Pontone G, Necas J, Kovalova S, Hristova K, Shiue I, Bogdanva V, Teixido Tura G, Sanchez V, Rodriguez-Palomares J, Gutierrez L, Gonzalez-Alujas T, Garcia-Dorado D, Forteza A, Evangelista A, Timoteo AT, Aguiar Rosa S, Cruz Ferreira R, Campbell R, Carrick D, Mccombe C, Tzemos N, Berry C, Sonecki P, Noda M, Setoguchi M, Ikenouchi T, Nakamura T, Yamamoto Y, Murakami T, Katou Y, Usui M, Ichikawa K, Isobe M, Kwon B, Roh J, Kim H, Ihm S, Barron AJ, Francis D, Mayet J, Wensel R, Kosiuk J, Dinov B, Bollmann A, Hindricks G, Breithardt O, Rio P, Moura Branco L, Galrinho A, Cacela D, Pinto Teixeira P, Afonso Nogueira M, Pereira-Da-Silva T, Abreu J, Teresa Timoteo A, Cruz Ferreira R, Pavlyukova E, Tereshenkova E, Karpov R, Piatkowski R, Kochanowski J, Opolski G, Barbier P, Mirea O, Guglielmo M, Savioli G, Cefalu C, Pudil R, Horakova L, Rozloznik M, Balestra C, Rimbas R, Enescu O, Calin S, Vinereanu D, Karsenty C, Hascoet S, Hadeed K, Semet F, Dulac Y, Alacoque X, Leobon B, Acar P, Dharma S, Sukmawan R, Soesanto A, Vebiona K, Firdaus I, Danny S, Driessen MMP, Sieswerda G, Post M, Snijder R, Van Dijk A, Leiner T, Meijboom F, Chrysohoou C, Tsitsinakis G, Tsiachris D, Aggelis A, Herouvim E, Vogiatzis I, Pitsavos C, Koulouris G, Stefanadis C, Erdei T, Edwards J, Braim D, Yousef Z, Fraser A, Avenatti E, Magnino C, Omede' P, Presutti D, Moretti C, Iannaccone A, Ravera A, Gaita F, Milan A, Veglio F, Barbier P, Scali M, Simioniuc A, Guglielmo M, Savioli G, Cefalu C, Mirea O, Fusini L, Dini F, Okura H, Murata E, Kataoka T, Zaroui A, Ben Halima M, Mourali M, Mechmeche R, Rodriguez Palomares JF, Gutierrez L, Maldonado G, Garcia G, Otaegui I, Garcia Del Blanco B, Teixido G, Gonzalez Alujas M, Evangelista A, Garcia Dorado D, Godinho AR, Correia A, Rangel I, Rocha A, Rodrigues J, Araujo V, Almeida P, Macedo F, Maciel M, Rekik B, Mghaieth F, Aloui H, Boudiche S, Jomaa M, Ayari J, Tabebi N, Farhati A, Mourali S, Dekleva M, Markovic-Nikolic N, Zivkovic M, Stankovic A, Boljevic D, Korac N, Beleslin B, Arandjelovic A, Ostojic M, Galli E, Guirette Y, Auffret V, Daudin M, Fournet M, Mabo P, Donal E, Chin CWL, Luo E, Hwan J, White A, Newby D, Dweck M, Carstensen HG, Larsen LH, Hassager C, Kofoed KF, Jensen JS, Mogelvang R, Kowalczyk M, Debska M, Kolesnik A, Dangel J, Kawalec W, Migliore R, Adaniya M, Barranco M, Miramont G, Gonzalez S, Tamagusuku H, Davidsen ES, Kuiper KKJ, Matre K, Gerdts E, Igual Munoz B, Maceira Gonzalez A, Erdociain Perales M, Estornell Erill J, Valera Martinez F, Miro Palau V, Piquer Gil M, Sepulveda Sanchez P, Cervera Zamora A, Montero Argudo A, Placido R, Silva Marques J, Magalhaes A, Guimaraes T, Nobre E Menezes M, Goncalves S, Ramalho A, Robalo Martins S, Almeida A, Nunes Diogo A, Abid L, Ben Kahla S, Charfeddine S, Abid D, Kammoun S, Tounsi A, Abid L, Abid D, Charfeddine S, Hammami R, Triki F, Akrout M, Mallek S, Hentati M, Kammoun S, Sirbu CF, Berrebi A, Huber A, Folliguet T, Yang LT, Shih J, Liu Y, Li Y, Tsai L, Luo C, Tsai W, Babukov R, Bartosh F, Bazilev V, Muraru D, Cavalli G, Addetia K, Miglioranza M, Veronesi F, Mihaila S, Tadic M, Cucchini U, Badano L, Lang R, Miyazaki S, Slavich M, Miyazaki T, Figini F, Lativ A, Chieffo A, Montrfano M, Alfieri O, Colombo A, Agricola E, Liu D, Hu K, Herrmann S, Stoerk S, Kramer B, Ertl G, Bijnens B, Weidemann F, Brand M, Butz T, Tzikas S, Van Bracht M, Roeing J, Wennemann R, Christ M, Grett M, Trappe HJ, Scherzer S, Geroldinger A, Krenn L, Roth C, Gangl C, Maurer G, Rosenhek R, Neunteufl T, Binder T, Bergler-Klein J, Martins E, Pinho T, Leite S, Azevedo O, Belo A, Campelo M, Amorim S, Rocha-Goncalves F, Goncalves L, Silva-Cardoso J, Ahn H, Kim K, Jeon H, Youn H, Haland T, Saberniak J, Leren I, Edvardsen T, Haugaa K, Ziolkowska L, Boruc A, Kowalczyk M, Turska-Kmiec A, Zubrzycka M, Kawalec W, Monivas Palomero V, Mingo Santos S, Goirigolzarri Artaza J, Rodriguez Gonzalez E, Rivero Arribas B, Castro Urda V, Dominguez Rodriguez F, Mitroi C, Gracia Lunar I, Fernadez Lozano I, Palecek T, Masek M, Kuchynka P, Fikrle M, Spicka I, Rysava R, Linhart A, Saberniak J, Hasselberg N, Leren I, Haland T, Borgquist R, Platonov P, Edvardsen T, Haugaa K, Ancona R, Comenale Pinto S, Caso P, Coopola M, Arenga F, Rapisarda O, D'onofrio A, Sellitto V, Calabro R, Rosca M, Popescu B, Calin A, Mateescu A, Beladan C, Jalba M, Rusu E, Zilisteanu D, Ginghina C, Pressman G, Cepeda-Valery B, Romero-Corral A, Moldovan R, Saenz A, Orban M, Samuel S, Fijalkowski M, Fijalkowska M, Gilis-Siek N, Blaut K, Galaska R, Sworczak K, Gruchala M, Fijalkowski M, Nowak R, Gilis-Siek N, Fijalkowska M, Galaska R, Gruchala M, Ikonomidis I, Triantafyllidi H, Trivilou P, Tzortzis S, Papadopoulos C, Pavlidis G, Paraskevaidis I, Lekakis J, Kaymaz C, Aktemur T, Poci N, Ozturk S, Akbal O, Yilmaz F, Tokgoz Demircan H, Kirca N, Tanboga I, Ozdemir N, Greiner S, Jud A, Aurich M, Hess A, Hilbel T, Hardt S, Katus H, D'ascenzi F, Cameli M, Alvino F, Lisi M, Focardi M, Solari M, Bonifazi M, Mondillo S, Konopka M, Krol W, Klusiewicz A, Burkhard K, Chwalbinska J, Pokrywka A, Dluzniewski M, Braksator W, King GJ, Coen K, Gannon S, Fahy N, Kindler H, Clarke J, Iliuta L, Rac-Albu M, Placido R, Robalo Martins S, Guimaraes T, Nobre E Menezes M, Cortez-Dias N, Francisco A, Silva G, Goncalves S, Almeida A, Nunes Diogo A, Kyu K, Kong W, Songco G, Galupo M, Castro M, Shin Hnin W, Ronald Lee C, Poh K, Milazzo V, Di Stefano C, Tosello F, Leone D, Ravera A, Sabia L, Sobrero G, Maule S, Veglio F, Milan A, Jamiel AM, Ahmed AM, Farah I, Al-Mallah MH, Petroni R, Magnano R, Bencivenga S, Di Mauro M, Petroni S, Altorio S, Romano S, Penco M, Kumor M, Lipczynska M, Klisiewicz A, Wojcik A, Konka M, Kozuch K, Szymanski P, Hoffman P, Rimbas R, Rimbas M, Enescu O, Mihaila S, Calin S, Vinereanu D, Donal E, Reynaud A, Lund L, Persson H, Hage C, Oger E, Linde C, Daubert J, Maria Oliveira Lima M, Costa H, Gomes Da Silva M, Noman Alencar M, Carmo Pereira Nunes M, Costa Rocha M, Abid L, Charfeddine S, Ben Kahla S, Abid D, Siala A, Hentati M, Kammoun S, Kovalova S, Necas J, Ozawa K, Funabashi N, Takaoka H, Kobayashi Y, Matsumura Y, Wada M, Hirakawa D, Yasuoka Y, Morimoto N, Takeuchi H, Kitaoka H, Sugiura T, Lakkas L, Naka K, Ntounousi E, Gkirdis I, Koutlas V, Bechlioulis A, Pappas K, Katsouras C, Siamopoulos K, Michalis L, Naka K, Evangelou D, Kalaitzidis R, Bechlioulis A, Lakkas L, Gkirdis I, Tzeltzes G, Nakas G, Katsouras C, Michalis L, Generati G, Bandera F, Pellegrino M, Labate V, Alfonzetti E, Guazzi M, Zagatina A, Zhuravskaya N, Al-Mallah M, Alsaileek A, Qureshi W, Karsenty C, Hascoet S, Peyre M, Hadeed K, Alacoque X, Amadieu R, Leobon B, Dulac Y, Acar P, Yamanaka Y, Sotomi Y, Iwakura K, Inoue K, Toyoshima Y, Tanaka K, Oka T, Tanaka N, Orihara Y, Fujii K, Soulat-Dufour L, Lang S, Boyer-Chatenet L, Van Der Vynckt C, Ederhy S, Adavane S, Haddour N, Boccara F, Cohen A, Huitema M, Boerman S, Vorselaars V, Grutters J, Post M, Gopal AS, Saha S, Toole R, Kiotsekoglou A, Cao J, Reichek N, Meyer CG, Altiok E, Al Ateah G, Lehrke M, Becker M, Lotfi S, Autschbach R, Marx N, Hoffmann R, Frick M, Nemes A, Sepp R, Kalapos A, Domsik P, Forster T, Caro Codon J, Blazquez Bermejo Z, Lopez Fernandez T, Valbuena Lopez SC, Iniesta Manjavacas AM, De Torres Alba F, Dominguez Melcon F, Pena Conde L, Moreno Yanguela M, Lopez-Sendon JL, Nemes A, Lengyel C, Domsik P, Kalapos A, Orosz A, Varkonyi T, Forster T, Rendon J, Saldarriaga CI, Duarte N, Nemes A, Domsik P, Kalapos A, Forster T, Nemes A, Domsik P, Kalapos A, Sepp R, Foldeak D, Borbenyi Z, Forster T, Hamdy A, Fereig H, Nabih M, Abdel-Aziz A, Ali A, Broyd C, Wielandts JY, De Buck S, Michielsen K, Louw R, Garweg C, Nuyts J, Ector J, Maes F, Heidbuchel H, Gillis K, Bala G, Tierens S, Cosyns B, Maurovich-Horvat P, Horvath T, Jermendy A, Celeng C, Panajotu A, Bartykowszki A, Karolyi M, Tarnoki A, Jermendy G, Merkely B. Poster session 2: Thursday 4 December 2014, 08:30-12:30 * Location: Poster area. Eur Heart J Cardiovasc Imaging 2014. [DOI: 10.1093/ehjci/jeu252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Wielandts JY, De Buck S, Ector J, Nuyens D, Maes F, Heidbuchel H. Left ventricular four-dimensional rotational angiography with low radiation dose through interphase registration. Europace 2014; 17:152-9. [DOI: 10.1093/europace/euu159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Elen A, Crijns W, Isebaert S, Haustermans K, Maes F. OC-0168: Impact of CT-MR registration imprecision on treatment planning for prostate cancer. Radiother Oncol 2014. [DOI: 10.1016/s0167-8140(15)30273-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Joye I, Van Herck H, Slagmolen P, Defraene G, Hortobagyi E, Maes F, Haustermans K. OC-0498: CTV delineation for rectal cancer treatment:ambiguities defined by a national review project. Radiother Oncol 2014. [DOI: 10.1016/s0167-8140(15)30603-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Crijns W, Defraene G, Van Herck H, Slagmolen P, Haustermans K, Maes F, Van den Heuvel F. PO-0879: Dosimetric fluence correction in non-rigid IMRT adaptation: preserving the penumbra margin. Radiother Oncol 2014. [DOI: 10.1016/s0167-8140(15)30997-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Maes F, Sabbe BGC. [Alexithymia in fibromyalgia: prevalence]. Tijdschr Psychiatr 2014; 56:798-806. [PMID: 25510454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
BACKGROUND In fibromyalgia, problems of affect regulation are considered important. Alexithymia, too, is related to disturbed affect regulation. Recognising alexithymia is important with regard to the doctor-patient relationship, the pitfalls in this relationship and the therapeutic strategy. AIM To look into the prevalence of alexithymia in fibromyalgia and find out which measures were used. METHOD We reviewed the literature systematically using Medline, PubMed and Cochrane and key words. RESULTS We found 11 relevant studies which revealed a significantly high prevalence of alexithymia in fibromyalgia patients, namely between 15 and 52%, whereas the prevalence in the general population was only 6 to 8%. All of these studies used the Toronto Alexithymia Scale (20-item or 26-item version) as the only test for alexithymia. Male fibromyalgia patients were not examined adequately, nor were patients in a residential setting. Three studies used patients with a painful chronic condition as a control group, but we did not find any studies that involved psychiatric control groups. CONCLUSION In view of the high prevalence of alexithymia and the implications of this for therapy, we recommend that patients with fibromyalgia should be screened systematically for alexithymia. Further research involving male patients and residential fibromyalgia patients is required and future studies will have to include psychiatric control groups.
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Boland B, Dalleur O, Maes F, Scavée C, Henrard S. Anticoagulation should be started in older patients with atrial fibrillation. Eur Geriatr Med 2013. [DOI: 10.1016/j.eurger.2013.07.588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Barone-Rochette G, Pierard S, De Meester De Ravensteen C, Melchior J, Maes F, Pouleur AC, Vancraeynest D, Pasquet A, Vanoverschelde JL, Gerber BL. Independent predictor CMR of mortality in patient with surgical aortic stenosis. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht307.p274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Van Dessel J, Huang Y, Depypere M, Rubira-Bullen I, Maes F, Jacobs R. A comparative evaluation of cone beam CT and micro-CT on trabecular bone structures in the human mandible. Dentomaxillofac Radiol 2013; 42:20130145. [PMID: 23833320 DOI: 10.1259/dmfr.20130145] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [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: 12/14/2022] Open
Abstract
OBJECTIVES The main purpose of this study was to determine the accuracy of cone beam CT (CBCT) in measuring the trabecular bone microstructure, in comparison with micro-CT. The subobjective was to examine to what extent bone quality assessment is influenced by X-ray tube current and voltage settings as well as soft tissue surrounding the bone. METHODS Eight human mandibular bone samples were scanned using three different clinical exposure protocol within water (W1-3) and without water (NW1-3) by a high-resolution (80 µm) CBCT machine (3D Accuitomo 170(®); Morita, Kyoto, Japan). Subsequently, the samples underwent micro-CT scanning (SkyScan 1174®; SkyScan, Antwerp, Belgium). After image acquisition, similar volumes of interest of the trabecular structures captured with CBCT and micro-CT were aligned with each other. Segmentation was then performed, and the morphometric parameters were quantified within the volumes of interest by CTAn software (CTAnalyser(®); SkyScan, Antwerp, Belgium). Descriptive statistical analyses and multiple comparisons between all protocols were applied in R software. RESULTS High positive Pearson's correlation coefficients were observed between CBCT and micro-CT protocols for all tested morphometric indices except for trabecular thickness. No significant differences were observed between all exposure protocols except for trabecular separation. When examining the soft-tissue effect on trabecular bone structures, no significant differences between NW (1-3) and W (1-3) protocols were observed for all variables. CONCLUSIONS The present study demonstrated the potential of high-resolution CBCT imaging for in vivo applications of quantitative bone morphometry and bone quality assessment. However, the overestimation of morphometric parameters and acquisition settings in CBCT must be taken into account.
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Affiliation(s)
- J Van Dessel
- Department of Oral Health Science, Oral Imaging Center, KU Leuven, Leuven, Belgium
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Barone-Rochette G, Pierard S, Seldrum S, de Ravensteen CM, Melchior J, Maes F, Pouleur AC, Vancraeynest D, Pasquet A, Vanoverschelde JL, L Gerber B. 973Aortic valve area, stroke volume, left ventricular
hypertrophy, remodeling and fibrosis in aortic stenosis assessed by cardiac MRI.
Comparison between high and low gradient, and normal and low flow aortic
stenosis. Eur Heart J Cardiovasc Imaging 2013. [DOI: 10.1093/ehjci/jet070f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Barone-Rochette G, Pierard S, Seldrum S, De Meester de Ravensteen C, Melchior J, Maes F, Pouleur AC, Vancraeynest D, Pasquet A, Vanoverschelde JL, L Gerber B. 974Independent Predictor CMR of Mortality in Patient with
Surgical Aortic Stenosis. Eur Heart J Cardiovasc Imaging 2013. [DOI: 10.1093/ehjci/jet070bq] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Crijns W, Van Herck H, Slagmolen P, Haustermans K, Maes F, Van den Heuvel F. PO-0847: A strategy for non-MU preserving adaptive radiotherapy. Radiother Oncol 2013. [DOI: 10.1016/s0167-8140(15)33153-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Boland B, Maes F, Henrard S, Scavée C. Anticoagulation is largely underused in elderly patients with atrial fibrillation. Eur Geriatr Med 2012. [DOI: 10.1016/j.eurger.2012.07.286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Van Herck H, Crijns W, Slagmolen P, Maes F, Van den Heuvel F, Haustermans K. SU-E-J-138: Fast 2-D Fiducial Marker Detection on Sequential MV Projections in Arc Therapy. Med Phys 2012; 39:3684. [DOI: 10.1118/1.4734974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Crijns W, Slagmolen P, Maes F, Haustermans K, Van den Heuvel F. TH-E-BRB-03: Incorporating a Lateral Scan Effect Correction in a EBT3 Calibration Protocol. Med Phys 2012. [DOI: 10.1118/1.4736353] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Maes F, Claessens T, Moesen M, Van Oosterwyck H, Van Ransbeeck P, Verdonck P. Computational models for wall shear stress estimation in scaffolds: A comparative study of two complete geometries. J Biomech 2012; 45:1586-92. [DOI: 10.1016/j.jbiomech.2012.04.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 03/19/2012] [Accepted: 04/09/2012] [Indexed: 12/24/2022]
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Crijns W, Van Herck H, Slagmolen P, Haustermans K, Maes F, Van den Heuvel F. PO-0892 TARGET SURFACE BASED FLUENCE DEFORMATION, FOR ADAPTIVE INTENSITY MODULATED RADIOTHERAPY. Radiother Oncol 2012. [DOI: 10.1016/s0167-8140(12)71225-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Laperre K, Depypere M, van Gastel N, Torrekens S, Moermans K, Bogaerts R, Maes F, Carmeliet G. Development of micro-CT protocols for in vivo follow-up of mouse bone architecture without major radiation side effects. Bone 2011; 49:613-22. [PMID: 21763477 DOI: 10.1016/j.bone.2011.06.031] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Revised: 05/26/2011] [Accepted: 06/24/2011] [Indexed: 10/18/2022]
Abstract
In vivo micro-computed tomography (micro-CT) will offer unique information on the time-related changes in bone mass and structure of living mice, provided that radiation-induced side effects are prevented. Lowering the radiation dose, however, inevitably decreases the image quality. In this study we developed and validated a protocol for in vivo micro-CT imaging of mouse bone architecture that retains high quality images but avoids radiation-induced side effects on bone structure and hematological parameters. The left hindlimb of male C57Bl/6 mice was scanned in vivo at 3 consecutive time points, separated each time by a 2-week interval. Two protocols for in vivo micro-CT imaging were evaluated, with pixel sizes of 9 and 18 μm and administered radiation doses of 434 mGy and 166 mGy per scan, respectively. These radiation doses were found not to influence trabecular or cortical bone architecture in pre-pubertal or adult mice. In addition, there was no evidence for hematological side effects as peripheral blood cell counts and the colony-forming capacity of hematopoietic progenitor cells from bone marrow and spleen were not altered. Although the images obtained with these in vivo micro-CT protocols were more blurred than those obtained with high resolution (5 μm) ex vivo CT imaging, longitudinal follow-up of trabecular bone architecture in an orchidectomy model proved to be feasible using the 9 μm pixel size protocol in combination with a suitable bone segmentation technique (i.e. local thresholding). The image quality of the 18 μm pixel size protocol was too degraded for accurate bone segmentation and the use of this protocol is therefore restricted to monitor marked changes in bone structure such as bone metastatic lesions or fracture healing. In conclusion, we developed two micro-CT protocols which are appropriate for detailed as well as global longitudinal studies of mouse bone architecture and lack noticeable radiation-induced side effects.
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Affiliation(s)
- K Laperre
- Laboratory of Experimental Medicine and Endocrinology, K.U.Leuven, Leuven, Belgium
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Casteels C, Vandeputte C, Rangarajan JR, Dresselaers T, Riess O, Bormans G, Maes F, Himmelreich U, Nguyen H, Van Laere K. Metabolic and type 1 cannabinoid receptor imaging of a transgenic rat model in the early phase of Huntington disease. Exp Neurol 2011; 229:440-9. [PMID: 21459091 DOI: 10.1016/j.expneurol.2011.03.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 03/11/2011] [Accepted: 03/21/2011] [Indexed: 01/11/2023]
Abstract
Several lines of evidence imply early alterations in metabolic and endocannabinoid neurotransmission in Huntington disease (HD). Using [(18)F]MK-9470 and small animal PET, we investigated for the first time cerebral changes in type 1 cannabinoid (CB1) receptor binding in vivo in pre-symptomatic and early symptomatic rats of HD (tgHD), in relation to glucose metabolism, morphology and behavioral testing for motor and cognitive function. Twenty-three Sprague-Dawley rats (14 tgHD and 9 wild-types) were investigated between the age of 2 and 11 months. Relative glucose metabolism and parametric CB1 receptor images were anatomically standardized to Paxinos space and analyzed voxel-wise. Volumetric microMRI imaging was performed to assess HD neuropathology. Within the first 10 months, bilateral volumes of caudate-putamen and lateral ventricles did not significantly differ between genotypes. Longitudinal- and genotype evolution showed that relative [(18)F]MK-9470 binding progressively decreased in the caudate-putamen and lateral globus pallidus of tgHD rats (-8.3%, p≤1.1×10(-5) at 5 months vs. -10.9%, p<1.5×10(-5) at 10 months). In addition, relative glucose metabolism increased in the bilateral sensorimotor cortex of 2-month-old tgHD rats (+8.1%, p≤1.5×10(-5)), where it was positively correlated to motor function at that time point. TgHD rats developed cognitive deficits at 6 and 11 months of age. Our findings point to early regional dysfunctions in endocannabinoid signalling, involving the lateral globus pallidus and caudate-putamen. In vivo CB1 receptor measurements using [(18)F]MK-9470 may thus be a useful early biomarker for HD. Our results also provide evidence of subtle motor and cognitive deficits at earlier stages than previously described.
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Affiliation(s)
- C Casteels
- Division of Nuclear Medicine, KU Leuven and University Hospital Leuven, Belgium.
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Vande Velde G, Rangarajan JR, Toelen J, Dresselaers T, Ibrahimi A, Krylychkina O, Vreys R, Van der Linden A, Maes F, Debyser Z, Himmelreich U, Baekelandt V. Evaluation of the specificity and sensitivity of ferritin as an MRI reporter gene in the mouse brain using lentiviral and adeno-associated viral vectors. Gene Ther 2011; 18:594-605. [PMID: 21346786 DOI: 10.1038/gt.2011.2] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The development of in vivo imaging protocols to reliably track transplanted cells or to report on gene expression is critical for treatment monitoring in (pre)clinical cell and gene therapy protocols. Therefore, we evaluated the potential of lentiviral vectors (LVs) and adeno-associated viral vectors (AAVs) to express the magnetic resonance imaging (MRI) reporter gene ferritin in the rodent brain. First, we compared the induction of background MRI contrast for both vector systems in immune-deficient and immune-competent mice. LV injection resulted in hypointense (that is, dark) changes of T(2)/T(2)(*) (spin-spin relaxation time)-weighted MRI contrast at the injection site, which can be partially explained by an inflammatory response against the vector injection. In contrast to LVs, AAV injection resulted in reduced background contrast. Moreover, AAV-mediated ferritin overexpression resulted in significantly enhanced contrast to background on T(2)(*)-weighted MRI. Although sensitivity associated with the ferritin reporter remains modest, AAVs seem to be the most promising vector system for in vivo MRI reporter gene imaging.
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Affiliation(s)
- G Vande Velde
- Laboratory for Neurobiology and Gene Therapy, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium
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Tang M, Kriatselis C, Nedios S, Roser M, Fleck E, Gerds-Li JH, De Buck S, Ector J, La Gerche A, Maes F, Hein Heidbuchel H, Doshi SK, Neuzil P, Reddy VY, Lickfett L, Becker P, Noe P, Linhart M, Lewalter T, Schrickel JW, Nickenig G, Mittmann-Braun EL, Wieczorek M, Hoeltgen R, Braun P, Sinha AM, Mahnkopf C, Ritscher G, Burgon N, Schmidt M, Marschang H, Marrousche NF, Brachmann J. Abstracts: New techniques for atrial fibrillation ablation. Europace 2009. [DOI: 10.1093/europace/euq201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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41
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Loubele M, Jacobs R, Maes F, Denis K, White S, Coudyzer W, Lambrichts I, van Steenberghe D, Suetens P. Image quality vs radiation dose of four cone beam computed tomography scanners. Dentomaxillofac Radiol 2008; 37:309-18. [PMID: 18757715 DOI: 10.1259/dmfr/16770531] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To evaluate image quality by examining segmentation accuracy and assess radiation dose for cone beam CT (CBCT) scanners. METHODS A skull phantom, scanned by a laser scanner, and a contrast phantom were used to evaluate segmentation accuracy. The contrast phantom consisted of a polymethyl methacrylate (PMMA) cylinder with cylindrical inserts of air, bone and PMMA. The phantoms were scanned on the (1) Accuitomo 3D, (2) MercuRay, (3) NewTom 3G, (4) i-CAT and (5) Sensation 16. The structures were segmented with an optimal threshold. Thicknesses of the bone of the mandible and the diameter of the cylinders in the contrast phantom were measured across lines at corresponding places in the CT image vs a ground truth. The accuracy was in the 95th percentile of the difference between corresponding measurements. The correlation between accuracy in skull and contrast phantom was calculated. The radiation dose was assessed by DPI(100,c) (dose profile integral (100,c)) at the central hole of a CT dose index (CTDI) phantom. RESULTS The results for the DPI(100,c) were 107 mGy mm for (1), 1569 mGy mm for (2), 446 mGy mm for (3), 249 mGy mm for (4) and 1090 mGy mm for (5). The segmentations in the contrast phantom were submillimeter accurate in all scanners. The segmentation accuracy of the mandible was 2.9 mm for (1), 4.2 mm for (2), 3.4 mm for (3), 1.0 mm for (4) and 1.2 mm for (5). The correlation between measurements in the contrast and skull phantom was below 0.37 mm. CONCLUSIONS The best radiation dose vs image quality was found for the i-CAT.
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Affiliation(s)
- M Loubele
- ESAT-PSI, Katholieke Universiteit Leuven, Belgium
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Loubele M, Maes F, Jacobs R, van Steenberghe D, White SC, Suetens P. Comparative study of image quality for MSCT and CBCT scanners for dentomaxillofacial radiology applications. Radiat Prot Dosimetry 2008; 129:222-226. [PMID: 18583372 DOI: 10.1093/rpd/ncn154] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The image quality of four cone-beam computed tomography (CBCT) scanners dedicated for dentomaxillofacial imaging and one multi-slice computed tomography (MSCT) scanner was compared. For the MSCT scanner, a clinical and a low-dose protocol for oral indications were evaluated. The image quality was assessed by dedicated software that allows an automated analysis of accuracy measurements and evaluation of metal artefacts on two image quality phantoms. Bone was segmented with sub-millimetre accuracyin all scanners.
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Affiliation(s)
- M Loubele
- ESAT-PSI, KULeuven, Medical Imaging Center, Herestraat 49 bus 7003, 3000 Leuven, Belgium.
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Loubele M, Van Assche N, Carpentier K, Maes F, Jacobs R, van Steenberghe D, Suetens P. Comparative localized linear accuracy of small-field cone-beam CT and multislice CT for alveolar bone measurements. ACTA ACUST UNITED AC 2007; 105:512-8. [PMID: 17900939 DOI: 10.1016/j.tripleo.2007.05.004] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2006] [Revised: 04/09/2007] [Accepted: 05/03/2007] [Indexed: 12/18/2022]
Abstract
OBJECTIVES To compare the accuracy of cone-beam computerized tomography (CBCT) and multislice CT (MSCT) for linear jaw bone measurements. STUDY DESIGN An ex vivo formalin-fixed human maxilla was imaged with both CBCT (Accuitomo 3D; Morita, Kyoto, Japan) and MSCT (4-slice Somatom VolumeZoom and 16-slice Somatom Sensation 16; Siemens, Erlangen, Germany). The MSCT images were reconstructed using different reconstruction filters to optimize bone visualization (U70u and U90u for VolumeZoom, H30s and H60s for Sensation 16). Before scanning, triplets of small gutta-percha markers were glued onto the soft tissues overlying the maxillary bone on the top and on both sides of the alveolar ridge to define a set of reproducible linear measurements in 11 planes. Image measurements were performed by 2 observers. The gold standard was determined by means of physical measurements with a caliper by 3 observers. RESULTS The accuracy of the linear measurements was 0.35 +/- 1.31 mm (U70u) and 0.06 +/- 1.23 mm (U90u) for the Somatom VolumeZoom, 0.24 +/- 1.20 mm (H60s) and 0.54 +/- 1.14 mm (H30s) for the Sensation 16, and -0.09 +/- 1.64 mm for the Accuitomo 3D. Statistical analysis with 2-way analysis of variance showed no significant inter- or intraobserver disagreement for the physical or the radiologic measurements. There was also no significant difference for the measurements on the different reconstruction filters. CONCLUSION Both CBCT and MSCT yield submillimeter accuracy for linear measurements on an ex vivo specimen.
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Affiliation(s)
- M Loubele
- Medical Image Computing (ESAT/PSI), Faculty of Engineering, Katholieke Universiteit Leuven, Leuven, Belgium.
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Mollemans W, Schutyser F, Nadjmi N, Maes F, Suetens P. Predicting soft tissue deformations for a maxillofacial surgery planning system: From computational strategies to a complete clinical validation. Med Image Anal 2007; 11:282-301. [PMID: 17493864 DOI: 10.1016/j.media.2007.02.003] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 08/03/2006] [Accepted: 02/15/2007] [Indexed: 11/24/2022]
Abstract
In the field of maxillofacial surgery, there is a huge demand from surgeons to be able to pre-operatively predict the new facial outlook after surgery. Besides the big interest for the surgeon during the planning, it is also an essential tool to improve the communication between the surgeon and his patient. In this work, we compare the usage of four different computational strategies to predict this new facial outlook. These four strategies are: a linear Finite Element Model (FEM), a non-linear Finite Element Model (NFEM), a Mass Spring Model (MSM) and a novel Mass Tensor Model (MTM). For true validation of these four models we acquired a data set of 10 patients who underwent maxillofacial surgery, including pre-operative and post-operative CT data. For all patient data we compared in a quantitative validation the predicted facial outlook, obtained with one of the four computational models, with post-operative image data. During this quantitative validation distance measurements between corresponding points of the predicted and the actual post-operative facial skin surface, are quantified and visualised in 3D. Our results show that the MTM and linear FEM predictions achieve the highest accuracy. For these models the average median distance measures only 0.60 mm and even the average 90% percentile stays below 1.5 mm. Furthermore, the MTM turned out to be the fastest model, with an average simulation time of only 10 s. Besides this quantitative validation, a qualitative validation study was carried out by eight maxillofacial surgeons, who scored the visualised predicted facial appearance by means of pre-defined statements. This study confirmed the positive results of the quantitative study, so we can conclude that fast and accurate predictions of the post-operative facial outcome are possible. Therefore, the usage of a maxillofacial soft tissue prediction system is relevant and suitable for daily clinical practice.
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Affiliation(s)
- W Mollemans
- Medical Image Computing (Radiology - ESAT/PSI), Faculties of Medicine and Engineering, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium.
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Slagmolen P, Roels S, Loeckx D, Maes F, Haustermans K. SU-DD-A4-01: Nonrigid Registration of Mesorectal Region for PET Signal Follow-Up During Radiation Therapy. Med Phys 2007. [DOI: 10.1118/1.2760326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Palmieri F, De Keyzer F, Maes F, Van Breuseghem I. Magnetization transfer analysis of cartilage repair tissue: a preliminary study. Skeletal Radiol 2006; 35:903-8. [PMID: 16738915 DOI: 10.1007/s00256-006-0146-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 12/26/2005] [Accepted: 03/29/2006] [Indexed: 02/02/2023]
Abstract
PURPOSE To evaluate the magnetization transfer ratio (MTR) after two different cartilage repair procedures, and to compare these data with the MTR of normal cartilage. DESIGN AND PATIENTS Twenty-seven patients with a proven cartilage defect were recruited: 13 were treated with autologous chondrocyte implantation (ACI) and 14 were treated with the microfracture technique (MFR). All patients underwent MRI examinations with MT-sequences before the surgical treatment, after 12 months (26 patients) and after 24 months (11 patients). Eleven patients received a complete follow-up study at all three time points (five of the ACI group and six of the MFR group). All images were transferred to a workstation to calculate MTR images. For every MT image set, different ROIs were delineated by two radiologists. Means were calculated per ROI type in the different time frames and in both groups of cartilage repair. The data were analyzed with unpaired t- and ANOVA tests, and by calculating Pearson's correlation coefficient. RESULTS No significant differences were found in the MTR of fatty bone marrow, muscle and normal cartilage in the different time frames. There was a significant but small difference between the MTR of normal cartilage and the cartilage repair area after 12 months for both procedures. After 24 months, the MTR of ACI repaired cartilage (0.31+/-0.07) was not significantly different from normal cartilage MTR (0.34+/-0.05). The MTR of MFR repaired cartilage (0.28+/-0.02), still showed a significant difference from normal cartilage. CONCLUSION The differences between damaged and repaired cartilage MTR are too small to enable MT-imaging to be a useful tool for postoperative follow-up of cartilage repair procedures. There is, however, an evolution towards normal MTR-values in the cartilage repair tissue (especially after ACI repair).
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Affiliation(s)
- F Palmieri
- Department of Radiology, University Federico II, Via Pansini 5, 80131 Naples, Italy
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Jani J, Breysem L, Maes F, Boulvain M, Roubliova X, Lewi L, Vaast P, Biard JM, Cannie M, Deprest J. Accuracy of magnetic resonance imaging for measuring fetal sheep lungs and other organs. Ultrasound Obstet Gynecol 2005; 25:270-276. [PMID: 15736207 DOI: 10.1002/uog.1866] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
OBJECTIVE Lung volume measurement by fetal magnetic resonance imaging (fetMRI) has been used to predict survival of fetuses with isolated congenital diaphragmatic hernia (CDH). So far, the accuracy and precision of fetMRI for volumetry of either the normal or hypoplastic developing lung has not been formally studied. METHODS A total of nine sheep carrying 14 fetuses underwent fetMRI under general anesthesia at a mean of 118 days' gestational age (term = 145 days). A total of 61 organs were measured in nine normal fetal sheep and five that underwent surgical creation of diaphragmatic hernia (DH), so as to induce pulmonary hypoplasia. Lungs were measured on T2-WI (weighted images) in three different planes, while liver and kidneys were measured in the axial (T1-WI) and sagittal (T2-WI) planes, respectively. Necropsy was done within 24 h after fetMRI to determine the volume postmortem by the water displacement method. Values were linearly correlated and a Bland and Altman analysis was done for volume measurement comparison, calculating means +/- SD, bias (mean of the difference of volume measurements), precision (SD of the difference) and absolute and proportionate limits of agreement for both methods. The accuracy of fetMRI volume measurement was determined for different organ groups by calculating the median relative error and precision index, both being measures of error in proportion to the magnitude of the volume measured, as a clinically relevant proxy of potential errors. RESULTS The fetMRI volume measurements were on average larger than postmortem volumes, except for the kidneys. Kidney volume determination had a relative error of 29%, while measurements of larger organs had larger relative errors (42% for liver). Normal lungs were less accurately measured in the coronal or sagittal than in the axial plane (relative error 53%, 73% and 38%, respectively; P < 0.05 for sagittal vs. axial). Axially-measured lung volumes were more accurate for lungs of normal sheep compared to DH lungs (relative error 38% vs. 73%, respectively; P < 0.05). CONCLUSION FetMRI measured systematically higher volumes for organs such as fetal liver or lung. This may be related to fluid loss or lack of perfusion at the time of necropsy. Measurement of lung volume by fetMRI was most accurate in the axial plane. Measurements of lung and liver volumes by fetMRI in normal sheep were both in agreement with volumes measured at necropsy. Loss of accuracy for DH-lungs in comparison with the accuracy when measuring other similarly small organs, such as kidneys, suggests that fetMRI measurements can be less accurate for hypoplastic lungs related to CDH. With improving hardware, it might become easier to render the fetal lung and determine its volume reliably.
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Affiliation(s)
- J Jani
- Centre for Surgical Technologies, Faculty of Medicine, Katholieke Universiteit Leuven, Belgium
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Loubele M, Jacobs R, Maes F, Schutyser F, Debaveye D, Bogaerts R, Coudyzer W, Vandermeulen D, van Cleynenbreugel J, Marchal G, Suetens P. Radiation dose vs. image quality for low-dose CT protocols of the head for maxillofacial surgery and oral implant planning. Radiat Prot Dosimetry 2005; 117:211-6. [PMID: 16461498 DOI: 10.1093/rpd/nci749] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The goal of this study was to determine the acquisition parameters for a low-dose multi-slice CT protocol and to compare the effective dose and the image quality of this low-dose protocol with the image quality of a clinical multi-slice CT protocol, routinely used for visualisation of the head. The low-dose protocol was derived from a clinical multi-slice CT protocol by lowering mA s and kV and increasing the pitch. The low-dose protocol yielded a dose reduction from 1.5 to 0.18 mSv for a multi-slice CT scan of the whole head, whereas noise in the low-dose CT images was increased. For bone segmentation, noise could be reduced by use of a non-linear edge preserving smoothing filter. Tests on ESP and skull phantom indicated that the accuracy of the measurements on low-dose CT is acceptable for image-based planning of maxillofacial and oral implant surgery, reducing the dose by a factor of 8.
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Affiliation(s)
- M Loubele
- Medical Image Computing-ESAT/PSI, Hospital Gasthuisberg, Katholieke Universiteit Leuven, Herestraat 49, B-3000 Leuven, Belgium.
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Coenegrachts KL, Hoogeveen RM, Vaninbroukx JA, Bosmans HT, Bielen DJ, Maleux G, Maes F, Hamaekers P, Oyen RH, Marchal GJ. A new multislab 3D balanced turbo field echo technique for imaging of the renal arteries without contrast agent. JBR-BTR 2004; 87:231-3. [PMID: 15587561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
An 80-year-old female patient with arterial hypertension and slowly progressive deterioration of renal function was referred to our department for investigation of the renal arteries. Imaging of the renal arteries with ultrasound was inconclusive, due to obesity. Subsequently, imaging was performed with balanced turbo field echo which is a newly developed technique in our department. This new technique for the moment is still combined with contrast-enhanced magnetic resonance angiography. A therapeutic digital subtraction angiography was performed for stent placement.
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Affiliation(s)
- K L Coenegrachts
- Department of Radiology, University Hospitals Gasthuisberg, Leuven, Belgium
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Herbots L, Maes F, D'hooge J, Claus P, Dymarkowski S, Mertens P, Mortelmans L, Bijnens B, Bogaert J, Rademakers FE, Sutherland GR. Quantifying myocardial deformation throughout the cardiac cycle: a comparison of ultrasound strain rate, grey-scale M-mode and magnetic resonance imaging. Ultrasound Med Biol 2004; 30:591-598. [PMID: 15183223 DOI: 10.1016/j.ultrasmedbio.2004.02.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2003] [Revised: 01/22/2004] [Accepted: 02/03/2004] [Indexed: 05/24/2023]
Abstract
Strain rate imaging (SRI) is a new ultrasound (US) approach to the quantification of regional myocardial deformation. It previously has been validated in vitro and in vivo against other imaging techniques. However, in all such studies, only peak strain values were compared, and the temporal evolution of the strain curve was not studied. Yet, it is the temporal evolution of the strain curves that contains the more important clinical information (e.g., asynchrony, viability, etc). Thus, the aim of this study was to compare the evolution of strain during the complete cardiac cycle as measured by US SRI, US grey-scale M-mode and magnetic resonance imaging (MRI). In 10 healthy volunteers and 20 patients with chronic ischaemic heart disease, radial deformation of the inferolateral segment of the left ventricle was measured by US SRI, US M-mode and MRI. The correspondence of the temporal characteristics of these strain curves were compared by defining an intraclass correlation coefficient (ICC). In healthy volunteers, an overall good agreement (mean ICC: 0.75 and 0.63 for systole and diastole) was found between the different methods. However, in patients with abnormal segmental deformation and low peak strain values, the agreement was less (mean ICC: 0.42 and 0.32), but remained within acceptable limits for clinical decision making. Myocardial deformation measurements using SRI correlated well with MRI and US M-mode measurements throughout the complete cardiac cycle.
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Affiliation(s)
- L Herbots
- Department of Cardiology, University Hospital Gasthuisberg, Katholieke Universiteit Leuven, Leuven, Belgium.
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