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Koetzier LR, Mastrodicasa D, Szczykutowicz TP, van der Werf NR, Wang AS, Sandfort V, van der Molen AJ, Fleischmann D, Willemink MJ. Deep Learning Image Reconstruction for CT: Technical Principles and Clinical Prospects. Radiology 2023; 306:e221257. [PMID: 36719287 PMCID: PMC9968777 DOI: 10.1148/radiol.221257] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 09/26/2022] [Accepted: 10/13/2022] [Indexed: 02/01/2023]
Abstract
Filtered back projection (FBP) has been the standard CT image reconstruction method for 4 decades. A simple, fast, and reliable technique, FBP has delivered high-quality images in several clinical applications. However, with faster and more advanced CT scanners, FBP has become increasingly obsolete. Higher image noise and more artifacts are especially noticeable in lower-dose CT imaging using FBP. This performance gap was partly addressed by model-based iterative reconstruction (MBIR). Yet, its "plastic" image appearance and long reconstruction times have limited widespread application. Hybrid iterative reconstruction partially addressed these limitations by blending FBP with MBIR and is currently the state-of-the-art reconstruction technique. In the past 5 years, deep learning reconstruction (DLR) techniques have become increasingly popular. DLR uses artificial intelligence to reconstruct high-quality images from lower-dose CT faster than MBIR. However, the performance of DLR algorithms relies on the quality of data used for model training. Higher-quality training data will become available with photon-counting CT scanners. At the same time, spectral data would greatly benefit from the computational abilities of DLR. This review presents an overview of the principles, technical approaches, and clinical applications of DLR, including metal artifact reduction algorithms. In addition, emerging applications and prospects are discussed.
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Affiliation(s)
| | | | - Timothy P. Szczykutowicz
- From the Department of Radiology (L.R.K., D.M., A.S.W., V.S., D.F.,
M.J.W.) and Stanford Cardiovascular Institute (D.M., D.F., M.J.W.), Stanford
University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305-5105;
Department of Radiology, University of Wisconsin–Madison, School of
Medicine and Public Health, Madison, Wis (T.P.S.); Department of Radiology,
Erasmus Medical Center, Rotterdam, the Netherlands (N.R.v.d.W.); Clinical
Science Western Europe, Philips Healthcare, Best, the Netherlands (N.R.v.d.W.);
and Department of Radiology, Leiden University Medical Center, Leiden, the
Netherlands (A.J.v.d.M.)
| | - Niels R. van der Werf
- From the Department of Radiology (L.R.K., D.M., A.S.W., V.S., D.F.,
M.J.W.) and Stanford Cardiovascular Institute (D.M., D.F., M.J.W.), Stanford
University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305-5105;
Department of Radiology, University of Wisconsin–Madison, School of
Medicine and Public Health, Madison, Wis (T.P.S.); Department of Radiology,
Erasmus Medical Center, Rotterdam, the Netherlands (N.R.v.d.W.); Clinical
Science Western Europe, Philips Healthcare, Best, the Netherlands (N.R.v.d.W.);
and Department of Radiology, Leiden University Medical Center, Leiden, the
Netherlands (A.J.v.d.M.)
| | - Adam S. Wang
- From the Department of Radiology (L.R.K., D.M., A.S.W., V.S., D.F.,
M.J.W.) and Stanford Cardiovascular Institute (D.M., D.F., M.J.W.), Stanford
University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305-5105;
Department of Radiology, University of Wisconsin–Madison, School of
Medicine and Public Health, Madison, Wis (T.P.S.); Department of Radiology,
Erasmus Medical Center, Rotterdam, the Netherlands (N.R.v.d.W.); Clinical
Science Western Europe, Philips Healthcare, Best, the Netherlands (N.R.v.d.W.);
and Department of Radiology, Leiden University Medical Center, Leiden, the
Netherlands (A.J.v.d.M.)
| | - Veit Sandfort
- From the Department of Radiology (L.R.K., D.M., A.S.W., V.S., D.F.,
M.J.W.) and Stanford Cardiovascular Institute (D.M., D.F., M.J.W.), Stanford
University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305-5105;
Department of Radiology, University of Wisconsin–Madison, School of
Medicine and Public Health, Madison, Wis (T.P.S.); Department of Radiology,
Erasmus Medical Center, Rotterdam, the Netherlands (N.R.v.d.W.); Clinical
Science Western Europe, Philips Healthcare, Best, the Netherlands (N.R.v.d.W.);
and Department of Radiology, Leiden University Medical Center, Leiden, the
Netherlands (A.J.v.d.M.)
| | - Aart J. van der Molen
- From the Department of Radiology (L.R.K., D.M., A.S.W., V.S., D.F.,
M.J.W.) and Stanford Cardiovascular Institute (D.M., D.F., M.J.W.), Stanford
University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305-5105;
Department of Radiology, University of Wisconsin–Madison, School of
Medicine and Public Health, Madison, Wis (T.P.S.); Department of Radiology,
Erasmus Medical Center, Rotterdam, the Netherlands (N.R.v.d.W.); Clinical
Science Western Europe, Philips Healthcare, Best, the Netherlands (N.R.v.d.W.);
and Department of Radiology, Leiden University Medical Center, Leiden, the
Netherlands (A.J.v.d.M.)
| | - Dominik Fleischmann
- From the Department of Radiology (L.R.K., D.M., A.S.W., V.S., D.F.,
M.J.W.) and Stanford Cardiovascular Institute (D.M., D.F., M.J.W.), Stanford
University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305-5105;
Department of Radiology, University of Wisconsin–Madison, School of
Medicine and Public Health, Madison, Wis (T.P.S.); Department of Radiology,
Erasmus Medical Center, Rotterdam, the Netherlands (N.R.v.d.W.); Clinical
Science Western Europe, Philips Healthcare, Best, the Netherlands (N.R.v.d.W.);
and Department of Radiology, Leiden University Medical Center, Leiden, the
Netherlands (A.J.v.d.M.)
| | - Martin J. Willemink
- From the Department of Radiology (L.R.K., D.M., A.S.W., V.S., D.F.,
M.J.W.) and Stanford Cardiovascular Institute (D.M., D.F., M.J.W.), Stanford
University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305-5105;
Department of Radiology, University of Wisconsin–Madison, School of
Medicine and Public Health, Madison, Wis (T.P.S.); Department of Radiology,
Erasmus Medical Center, Rotterdam, the Netherlands (N.R.v.d.W.); Clinical
Science Western Europe, Philips Healthcare, Best, the Netherlands (N.R.v.d.W.);
and Department of Radiology, Leiden University Medical Center, Leiden, the
Netherlands (A.J.v.d.M.)
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Kim I, Kang H, Yoon HJ, Chung BM, Shin NY. Deep learning-based image reconstruction for brain CT: improved image quality compared with adaptive statistical iterative reconstruction-Veo (ASIR-V). Neuroradiology 2020; 63:905-912. [PMID: 33037503 DOI: 10.1007/s00234-020-02574-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [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: 07/06/2020] [Accepted: 09/29/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE To compare the image quality of brain computed tomography (CT) images reconstructed with deep learning-based image reconstruction (DLIR) and adaptive statistical iterative reconstruction-Veo (ASIR-V). METHODS Sixty-two patients underwent routine noncontrast brain CT scans and datasets were reconstructed with 30% ASIR-V and DLIR with three selectable reconstruction strength levels (low, medium, high). Objective parameters including CT attenuation, noise, noise reduction rate, artifact index of the posterior cranial fossa, and contrast-to-noise ratio (CNR) were measured at the levels of the centrum semiovale and basal ganglia. Subjective parameters including gray matter-white matter differentiation, sharpness, and overall diagnostic quality were also assessed and compared with the interobserver agreement. RESULTS There was a gradual reduction in the image noise and artifact index of the posterior cranial fossa as the strength levels of DLIR increased (all P < 0.001) compared with that of ASIR-V. CNR in both the centrum semiovale and basal ganglia levels also improved from the low to high strength levels of DLIR compared with that of ASIR-V (all P < 0.001). DLIR images with medium and high strength levels demonstrated the best subjective image quality scores among the reconstruction datasets. There was moderate to good interobserver agreement for the subjective image quality assessments with ASIR-V and DLIR. CONCLUSION On routine brain CT scans, optimized protocols with DLIR allowed significant reduction of noise and artifacts with improved subjective image quality compared with ASIR-V.
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Affiliation(s)
- Injoong Kim
- Department of Radiology, Veterans Health Service Medical Center, 53 Jinhwangdo-ro 61-gil, Gangdong-gu, Seoul, 05368, South Korea
| | - Hyunkoo Kang
- Department of Radiology, Veterans Health Service Medical Center, 53 Jinhwangdo-ro 61-gil, Gangdong-gu, Seoul, 05368, South Korea
| | - Hyun Jung Yoon
- Department of Radiology, Veterans Health Service Medical Center, 53 Jinhwangdo-ro 61-gil, Gangdong-gu, Seoul, 05368, South Korea
| | - Bo Mi Chung
- Department of Radiology, Veterans Health Service Medical Center, 53 Jinhwangdo-ro 61-gil, Gangdong-gu, Seoul, 05368, South Korea
| | - Na-Young Shin
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 06591, South Korea.
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Parizel PM, Philips CD. Traumatic Neuroemergency: Imaging Patients with Traumatic Brain Injury—An Introduction. In: Hodler J, Kubik-huch RA, von Schulthess GK, editors. Diseases of the Brain, Head and Neck, Spine 2020–2023. Cham: Springer International Publishing; 2020. pp. 77-92. [DOI: 10.1007/978-3-030-38490-6_7] [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]
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Abstract
Ultrasound, CT and MRI may all be used in the evaluation of the posterior fossa in neonates depending on the clinical scenario. Ultrasonography is particularly valuable for the evaluation of the neonatal brain because of the lack of ionizing radiation and the ability to perform exams at the bedside and, importantly, advancements in ultrasound technology now allow for diagnostic-quality imaging. While CT is still the initial imaging modality of choice in most neurologic emergencies, in the neonate, ultrasound is the first line in nontraumatic emergencies. The goal of this chapter is to discuss the ultrasound technique for evaluation of the cerebellum, to describe the normal sonographic and CT appearance of posterior fossa and to provide the classical findings of the most common cerebellar abnormalities. While ultrasound is able to accurately diagnosis a majority of cerebellar abnormalities in neonates, subsequent MR imaging remains essential to confirm findings and to detect associated abnormalities.
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Affiliation(s)
- Elizabeth Snyder
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
| | - Misun Hwang
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
| | - Bruno P Soares
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
| | - Aylin Tekes
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States.
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Liu X, Chen L, Qi W, Jiang Y, Liu Y, Zhang M, Hong N. Thin-slice brain CT with iterative model reconstruction algorithm for small lacunar lesions detection: Image quality and diagnostic accuracy evaluation. Medicine (Baltimore) 2017; 96:e9412. [PMID: 29390563 PMCID: PMC5758265 DOI: 10.1097/md.0000000000009412] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
This study was aimed to evaluate the image quality and lacunar lesion detection of thin-slice brain computed tomography (CT) images with different reconstruction algorithms, including filtered back projection (FBP), hybrid iterative reconstruction (HIR), and iterative model reconstruction (IMR) by comparison of routine slice images with FBP reconstruction. Sixty-one patients underwent noncontrast brain CT and images were reconstructed with a routine slice of 5.0 mm by FBP and thin slice of 1.0 mm by IMR, HIR, and FBP algorithms, respectively. Objective analyses included CT attenuation, noise, artifacts index of posterior cranial fossa, and contrast-to-noise ratio (CNR). Subjective analyses were performed according to overall image quality using a 5-point scale [1 (unacceptable) to 5 (excellent)]. In addition, lacunar lesion detection was compared in images with different reconstruction settings among 26 patients with lacunar lesions, with magnetic resonance imaging (MRI) as reference.Thin-slice IMR images enabled the lowest noise, artifacts index, and the best CNR. Both IMR and HIR thin-slice images enabled better scores in subjective image quality than routine slice FBP images. Moreover, both thin-slice IMR and HIR images enabled higher sensitivity and positive predictive value (PPV) in lesion detection of 35-mm lacunar lesions compared with routine slice FBP images.Thin-slice IMR images improve image quality, meanwhile yield better detection of small lacunar lesions in brain CT compared with routine slice FBP images.
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Affiliation(s)
- Xiaoyi Liu
- Department of Radiology, Peking University People's Hospital, Beijing
| | - Lei Chen
- Department of Radiology, Peking University People's Hospital, Beijing
| | - Weiwei Qi
- Department of Radiology, Peking University People's Hospital, Beijing
| | - Yan Jiang
- Clinical Science, Philips Healthcare, Shanghai, China
| | - Ying Liu
- Clinical Science, Philips Healthcare, Shanghai, China
| | - Miao Zhang
- Department of Radiology, Peking University People's Hospital, Beijing
| | - Nan Hong
- Department of Radiology, Peking University People's Hospital, Beijing
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Mormina E, Petracca M, Bommarito G, Piaggio N, Cocozza S, Inglese M. Cerebellum and neurodegenerative diseases: Beyond conventional magnetic resonance imaging. World J Radiol 2017; 9:371-388. [PMID: 29104740 PMCID: PMC5661166 DOI: 10.4329/wjr.v9.i10.371] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 07/18/2017] [Accepted: 08/02/2017] [Indexed: 02/06/2023] Open
Abstract
The cerebellum plays a key role in movement control and in cognition and cerebellar involvement is described in several neurodegenerative diseases. While conventional magnetic resonance imaging (MRI) is widely used for brain and cerebellar morphologic evaluation, advanced MRI techniques allow the investigation of cerebellar microstructural and functional characteristics. Volumetry, voxel-based morphometry, diffusion MRI based fiber tractography, resting state and task related functional MRI, perfusion, and proton MR spectroscopy are among the most common techniques applied to the study of cerebellum. In the present review, after providing a brief description of each technique’s advantages and limitations, we focus on their application to the study of cerebellar injury in major neurodegenerative diseases, such as multiple sclerosis, Parkinson’s and Alzheimer’s disease and hereditary ataxia. A brief introduction to the pathological substrate of cerebellar involvement is provided for each disease, followed by the review of MRI studies exploring structural and functional cerebellar abnormalities and by a discussion of the clinical relevance of MRI measures of cerebellar damage in terms of both clinical status and cognitive performance.
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Affiliation(s)
- Enricomaria Mormina
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
- Neuroradiology Unit, Department of Biomedical Sciences and Morphological and Functional Images, University of Messina, 98100 Messina, Italy
| | - Maria Petracca
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
- Department of Neuroscience, Reproductive Sciences and Odontostomatology, University of Naples Federico II, 80138 Naples, Italy
| | - Giulia Bommarito
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, 16132 Genoa, Italy
| | - Niccolò Piaggio
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, 16132 Genoa, Italy
- Department of Neuroradiology, San Martino Hospital, 16132 Genoa, Italy
| | - Sirio Cocozza
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80138 Naples, Italy
| | - Matilde Inglese
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, 16132 Genoa, Italy
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Rischall MA, Boegel KH, Palmer CS, Knoll B, Mckinney AM. MDCT Venographic Patterns of Dural Venous Sinus Compromise After Acute Skull Fracture. AJR Am J Roentgenol 2016; 207:852-8. [DOI: 10.2214/ajr.15.15972] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Hsu CCT, Kwan GNC, Singh D, Pratap J, Watkins TW. Principles and Clinical Application of Dual-energy Computed Tomography in the Evaluation of Cerebrovascular Disease. J Clin Imaging Sci 2016; 6:27. [PMID: 27512615 PMCID: PMC4964665 DOI: 10.4103/2156-7514.185003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [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: 03/31/2016] [Accepted: 05/23/2016] [Indexed: 01/03/2023] Open
Abstract
Dual-energy computed tomography (DECT) simultaneously acquires images at two X-ray energy levels, at both high- and low-peak voltages (kVp). The material attenuation difference obtained from the two X-ray energies can be processed by software to analyze material decomposition and to create additional image datasets, namely, virtual noncontrast, virtual contrast also known as iodine overlay, and bone/calcium subtraction images. DECT has a vast array of clinical applications in imaging cerebrovascular diseases, which includes: (1) Identification of active extravasation of iodinated contrast in various types of intracranial hemorrhage; (2) differentiation between hemorrhagic transformation and iodine staining in acute ischemic stroke following diagnostic and/or therapeutic catheter angiography; (3) identification of culprit lesions in intra-axial hemorrhage; (4) calcium subtraction from atheromatous plaque for the assessment of plaque morphology and improved quantification of luminal stenosis; (5) bone subtraction to improve the depiction of vascular anatomy with more clarity, especially at the skull base; (6) metal artifact reduction utilizing virtual monoenergetic reconstructions for improved luminal assessment postaneurysm coiling or clipping. We discuss the physical principles of DECT and review the clinical applications of DECT for the evaluation of cerebrovascular diseases.
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Affiliation(s)
- Charlie Chia-Tsong Hsu
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Gigi Nga Chi Kwan
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Dalveer Singh
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Jit Pratap
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Trevor William Watkins
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Queensland, Australia
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Sayan S, Kotan D. Levels of brain natriuretic peptide as a marker for the diagnosis and prognosis of acute ischemic stroke. ACTA ACUST UNITED AC 2016; 1:e16-22. [PMID: 28905014 DOI: 10.5114/amsad.2016.59751] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [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: 03/10/2016] [Accepted: 04/15/2016] [Indexed: 02/03/2023]
Abstract
Introduction The relationships between plasma levels of brain natriuretic peptide (BNP) and severity and location of stroke, prognosis, and infarct volume were investigated in acute ischemic stroke patients who presented within the first 24 hours (h) of stroke. Material and methods Brain natriuretic peptide levels were tested in 40 patients and 30 healthy controls. Infarct volume was automatically calculated by multi-slice computed tomography. Disease severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) at presentation, 24 h, 72 h and the 28th day. Progression was defined as an increase of more than two points in the NIHSS scores. Results The mean BNP levels were 284.16 ±382.79 at presentation and 273.78 ±451.91 at 72 h in the patient group, whereas the mean BNP level was 25.29 ±13.47 in controls. There was a statistically significant difference between the two groups (p < 0.001). Differences in BNP levels among patient subgroups according to the TOAST and OCSP classifications were not statistically significant (p = 0.534, p = 0.943, respectively). There was no significant correlation between plasma BNP level and infarct volume or NIHSS scores (p = 0.5, p = 0.07). A positive correlation was found between BNP levels and the length of the hospitalization period (p = 0.03 and r = 0.33). There was no statistically significant relationship between elevated plasma BNP levels and progression of disease (p = 0.08). Conclusions Plasma BNP levels were increased in the acute phase of stroke; therefore, BNP could be used as a biomarker for morbidity and mortality, even in patients without cardiac failure.
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Hébert J, Roncarolo F, Tampieri D, Cortes Md. 320-Row Multidetector CT Angiography in the Detection of Critical Cerebrovascular Anomalies. Can J Neurol Sci 2016; 43:543-8. [PMID: 26963444 DOI: 10.1017/cjn.2016.11] [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] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The acquisition of a new 320-row multidetector computed tomography angiography (CTA) scanner at the Montreal Neurological Institute and Hospital has provided higher quality imaging with less radiation exposure and shorter time of acquisition. However, its reliability has not been fully proven in critical vascular lesions when it comes to replacing a more invasive examination such as cerebral angiography. We wished to validate the accuracy of this equipment to investigate four common indications for patients to undergo conventional digital subtraction angiography: subarachnoid hemorrhage, vasospasm, unusual intracerebral hemorrhage, and unruptured aneurysm. METHODS Radiological reports and relevant imaging from 82 consecutive subjects who underwent a 320-row multidetector CTA followed by cerebral angiography from February 2010 to February 2014 were retrospectively analysed. A total of 102 cerebrovascular anomalies were found. Reports from both imaging modalities were compared to determine the diagnostic accuracy of CTA. RESULTS The overall sensitivity and specificity of 320-row multidetector CTA for detecting cerebrovascular abnormalities were, respectively, 97.60% and 63.20%. Similar results were obtained for all four categories of clinical indications. CONCLUSION Results obtained from CTA were consistent with those obtained on digital subtraction angiography regardless of the vascular pathology. To our knowledge, this study is the first validating the accuracy of 320-row CTA in diagnosing critical cerebrovascular lesions.
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Abstract
The evaluation of patients with diverse neurologic disorders was forever changed in the summer of 1973, when the first commercial computed tomography (CT) scanners were introduced. Until then, the detection and characterization of intracranial or spinal lesions could only be inferred by limited spatial resolution radioisotope scans, or by the patterns of tissue and vascular displacement on invasive pneumoencaphalography and direct carotid puncture catheter arteriography. Even the earliest-generation CT scanners - which required tens of minutes for the acquisition and reconstruction of low-resolution images (128×128 matrix) - could, based on density, noninvasively distinguish infarct, hemorrhage, and other mass lesions with unprecedented accuracy. Iodinated, intravenous contrast added further sensitivity and specificity in regions of blood-brain barrier breakdown. The advent of rapid multidetector row CT scanning in the early 1990s created renewed enthusiasm for CT, with CT angiography largely replacing direct catheter angiography. More recently, iterative reconstruction postprocessing techniques have made possible high spatial resolution, reduced noise, very low radiation dose CT scanning. The speed, spatial resolution, contrast resolution, and low radiation dose capability of present-day scanners have also facilitated dual-energy imaging which, like magnetic resonance imaging, for the first time, has allowed tissue-specific CT imaging characterization of intracranial pathology.
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Affiliation(s)
- Shervin Kamalian
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Michael H Lev
- Division of Emergency Radiology and Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Rajiv Gupta
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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Abstract
Computed tomography (CT) has had a profound effect on the practice of medicine. Both the spectrum of clinical applications and the role that CT has played in enhancing the depth of our understanding of disease have been profound. Although almost 90 000 articles on CT have been published in peer-reviewed journals over the past 40 years, fewer than 5% of these have been published in Radiology. Nevertheless, these almost 4000 articles have provided a basis for many important medical advances. By enabling a deepened understanding of anatomy, physiology, and pathology, CT has facilitated key advances in the detection and management of disease. This article celebrates this breadth of scientific discovery and development by examining the impact that CT has had on the diagnosis, characterization, and management of a sampling of major health challenges, including stroke, vascular diseases, cancer, trauma, acute abdominal pain, and diffuse lung diseases, as related to key technical advances in CT and manifested in Radiology.
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Affiliation(s)
- Geoffrey D Rubin
- From the Duke Clinical Research Institute and Department of Radiology, Duke University School of Medicine, PO Box 17969, 2400 Pratt St, Durham, NC 27715
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Notohamiprodjo S, Deak Z, Meurer F, Maertz F, Mueck FG, Geyer LL, Wirth S. Image quality of iterative reconstruction in cranial CT imaging: comparison of model-based iterative reconstruction (MBIR) and adaptive statistical iterative reconstruction (ASiR). Eur Radiol 2014; 25:140-6. [DOI: 10.1007/s00330-014-3374-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/09/2014] [Accepted: 07/22/2014] [Indexed: 11/30/2022]
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Fukuda A, Lin PJP, Matsubara K, Miyati T. Measurement of gantry rotation time in modern ct. J Appl Clin Med Phys 2014; 15:4517. [PMID: 24423850 PMCID: PMC5711247 DOI: 10.1120/jacmp.v15i1.4517] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 07/29/2013] [Accepted: 07/25/2013] [Indexed: 11/23/2022] Open
Abstract
The purpose of this study was to develop and evaluate a noninvasive method to assess rotation time in modern commercial computed tomography (CT) systems. The rotation time was measured at a selected nominal rotation time (400 ms) utilizing two types of solid‐state detectors: the RTI's CT Dose Profiler (CTDP) and Unfors’ Xi (Xi) probes. Either CTDP or Xi was positioned on the inner cover of the gantry and a sheet of lead (1 mm thick) placed on top of the detector. Since a pair of two successive peaks is used to determine the gantry rotation time, by necessity the helical scan must be employed. Upon completion of the data acquisition, these peak times were determined with the dedicated software to obtain rotation time. The average rotation time obtained with CTDP and Xi operated under the dedicated software was found to be 400.6 and 400.5 ms, respectively. The detector for this measurement need not be specifically designed for CT dosimetry. The measurements of CT scanner rotation time can be accomplished with a radiation probe designed for the CT application or a conventional radiation probe designed for radiography and fluoroscopy applications. It is also noteworthy to point out that the measurement results are in good agreement between the two radiation detector systems. Finally, clinical medical physicists should be aware of the accuracy and precision of gantry rotation time, and take into consideration for QA where and when applicable. PACS number: 87.57.Q‐
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Leiva-salinas C, Provenzale JM, Wintermark M. Responses to the 10 Most Frequently Asked Questions About Perfusion CT. AJR Am J Roentgenol 2011; 196:53-60. [DOI: 10.2214/ajr.10.5705] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abdeen N, Chakraborty S, Nguyen T, dos Santos M, Donaldson M, Heddon G, Schwarz B. Comparison of image quality and lens dose in helical and sequentially acquired head CT. Clin Radiol 2010; 65:868-73. [DOI: 10.1016/j.crad.2010.02.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Revised: 02/11/2010] [Accepted: 02/17/2010] [Indexed: 11/23/2022]
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Kampondeni S, Birbeck GL, Oostveen RJ, Hammond C, Potchen MJ. Alternative oblique head CT scanning technique reduces bone artifact and improves interpretability of brainstem anatomy. Neurol Int 2010; 2:e14. [PMID: 21577337 PMCID: PMC3093213 DOI: 10.4081/ni.2010.e14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [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: 05/12/2010] [Revised: 06/07/2010] [Accepted: 06/09/2010] [Indexed: 11/28/2022] Open
Abstract
Brainstem pathology due to infections, infarcts and tumors are common in developing countries, but neuroimaging technology in these resource-poor settings is often limited to single slice, and occasionally spiral, CT. Unlike multislice CT and MRI, single slice and spiral CT are compromised by bone artifacts in the posterior fossa due to the dense petrous bones, often making imaging of the brainstem non-diagnostic. With appropriate head positioning, the petrous ridges can be avoided with 40° sagittal oblique scans parallel to either petrous ridge. We describe an alternative sagittal oblique scanning technique that significantly reduces brainstem CT artifacts thereby improving clarity of anatomy. With Institutional Ethical approval, 13 adult patients were enrolled (5 males; 39%). All patients had routine axial brain CT and sagittal oblique scans with no lesions found. Images were read by 2 readers who gave a score for amount of artefact and clarity of structures in the posterior fossa. The mean artifact score was higher for routine axial images compared to sagittal oblique (2.92 vs. 1.23; P<0.0001). The mean anatomical certainty scores for the brainstem were significantly better in the sagittal oblique views compared to routine axial (1.23 vs. 2.77; P<0.0001). No difference was found between the two techniques with respect to the fourth ventricle or the cerebellum (axial vs. sag oblique: 1.15 vs. 1.27; P=0.37). When using single slice CT, the sagittal oblique scanning technique is valuable in improving clarity of anatomy in the brainstem if axial images are non-diagnostic due to bone artifacts.
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Affiliation(s)
- Sam Kampondeni
- Michigan State University, Department of Radiology, East Lansing, MI, USA
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Hamaguchi N, Kodera S. [Potential of helical scan technique in acute cerebral infarction assessment]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2010; 66:632-640. [PMID: 20702981 DOI: 10.6009/jjrt.66.632] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The high convenience of data collection by helical scanning, such as making multi planner reformat (MPR) and shortening scan time, means that the technique is widely used to diagnose various body parts. However, non-helical scanning is still a main current for plane brain computed tomography. The possibility of diagnosing acute cerebral infarction by helical scanning MPR was examined. It was found that image degradation in helical scanning had little influence on the physical evaluation of the characteristics of modulation transfer function and the noise power spectrum, etc. In the evaluation of the ischemic change occurring at the early stage made by examination of clinical images, the result was almost equal to that obtained by non-helical scanning, as the reported sensitivity was 52% and the specificity was 95%. This suggested that brain helical scanning MPR might be applied clinically. However, a disadvantage was confirmed as helical scanning had a higher exposure dose than non-helical scanning at the start and end of scanning. The results of this study indicated that helical scanning demonstrates sufficient convenience for the assessment of acute cerebral infarction at the basal nucleus level.
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Affiliation(s)
- Naoko Hamaguchi
- Department of Radiology, Sapporo Azabu Neurosurgical Hospital, Japan
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Suzuki S, Furui S, Ishitake T, Abe T, Machida H, Takei R, Ibukuro K, Watanabe A, Kidouchi T, Nakano Y. Lens exposure during brain scans using multidetector row CT scanners: methods for estimation of lens dose. AJNR Am J Neuroradiol 2010; 31:822-6. [PMID: 20044501 PMCID: PMC7964184 DOI: 10.3174/ajnr.a1946] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [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: 06/15/2009] [Accepted: 10/01/2009] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND PURPOSE Some recent studies on radiation lens injuries have indicated much lower dose thresholds than specified by the current radiation protection guidelines. The purpose of this research was to measure the lens dose during brain CT scans with multidetector row CT and to assess methods for estimating the lens dose. MATERIALS AND METHODS With 8 types of multidetector row CT scanners, both axial and helical scans were obtained for the head part of a human-shaped phantom by using normal clinical settings with the orbitomeatal line as the baseline. We measured the doses on both eyelids by using an RPLGD during whole-brain scans including the orbit with the starting point at the level of the inferior orbital rim. To assess the effect of the starting points on the lens doses, we measured the lens doses by using 2 other starting points for scanning (the orbitomeatal line and the superior orbital rim). RESULTS The CTDIvols and the lens doses during whole-brain CT including the orbit were 50.9-113.3 mGy and 42.6-103.5 mGy, respectively. The ratios of lens dose to CTDIvol were 80.6%-103.4%. The lens doses decreased as the starting points were set more superiorly. The lens doses during scans from the superior orbital rim were 11.8%-20.9% of the doses during the scans from the inferior orbital rim. CONCLUSIONS CTDIvol can be used to estimate the lens dose during whole-brain CT when the orbit is included in the scanning range.
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Affiliation(s)
- S Suzuki
- Department of Radiology, Teikyo University School of Medicine, Tokyo, Japan.
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21
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Saba L, Montisci R, Sanfilippo R, Mallarini G. Multidetector row CT of the brain and carotid artery: a correlative analysis. Clin Radiol 2009; 64:767-78. [PMID: 19589415 DOI: 10.1016/j.crad.2009.03.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2008] [Revised: 03/16/2009] [Accepted: 03/19/2009] [Indexed: 01/02/2023]
Abstract
AIM To evaluate the association between types of carotid plaque, the presence of prior ischaemic events detectable with CT, and patient's symptoms. MATERIALS AND METHODS Between January 2004 and May 2006, 112 patients were evaluated using multidetector row computed tomography angiography (MDCTA) of the carotid arteries and computed tomography (CT) of the brain. Carotid arteries were categorized by evaluating the degree of stenosis according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria, the type of plaque, and the presence of plaque ulceration. The brain was assessed via CT for the presence, type, and position of lesions. Chi-square tests, Student's t test, and simple logistic regression analysis were performed and the Cohen kappa test was applied for interobserver variability measurement. RESULTS The Chi-square test indicated a statistically significant association between the presence of fatty plaques (p=0.005) and CT-detectable lesions in the brain (p=0.004). Moreover, the number of patients with CT-detectable brain lesions was greater in patients with >70% stenosis than in those with <70% stenosis (p=0.007). Logistic regression confirmed the association between fatty plaque and symptoms (p=0.001), between >70% stenosis and symptoms (p=0.041), and an inverse association between calcified plaque and symptoms (p=0.009). CONCLUSION MDCTA allows adequate evaluation of the type of plaque. The results of the present study indicate that there is an association between cerebral lesions, symptoms, and fatty plaque in the carotid artery. The degree of stenosis also correlated with cerebral lesions and symptoms. According to the obtained data, the type of carotid plaque should be included among primary parameters in the classification of patients' risk class.
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Affiliation(s)
- L Saba
- Department of Imaging Science, Policlinico Universitario, s.s. 554 Monserrato (Cagliari) 09045, Italy.
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22
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Lourenco AP, Mayo-Smith WW, Tubbs RJ, Sidman R. Does 16-Detector Computed Tomography Improve Detection of Non-traumatic Subarachnoid Hemorrhage in the Emergency Department? J Emerg Med 2009; 36:171-5. [DOI: 10.1016/j.jemermed.2007.10.066] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Revised: 03/29/2007] [Accepted: 10/30/2007] [Indexed: 11/27/2022]
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Saba L, Sanfilippo R, Pascalis L, Montisci R, Mallarini G. Carotid Artery Abnormalities and Leukoaraiosis in Elderly Patients: Evaluation with MDCT. AJR Am J Roentgenol 2009; 192:W63-70. [DOI: 10.2214/ajr.07.3566] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Mathur S, Gadde S, Koteyar SS. Case report. Artefact misinterpretation on CT images of the head. Clin Radiol 2008; 63:1277-9. [PMID: 18929046 DOI: 10.1016/j.crad.2008.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2008] [Accepted: 05/12/2008] [Indexed: 11/15/2022]
Affiliation(s)
- S Mathur
- Department of Radiology, North Manchester General Hospital, Crumpsall, Manchester, UK.
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Ertl-Wagner B, Eftimov L, Blume J, Bruening R, Becker C, Cormack J, Brueckmann H, Reiser M. Cranial CT with 64-, 16-, 4- and single-slice CT systems-comparison of image quality and posterior fossa artifacts in routine brain imaging with standard protocols. Eur Radiol. 2008;18:1720-1726. [PMID: 18389247 DOI: 10.1007/s00330-008-0937-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2007] [Revised: 01/21/2008] [Accepted: 01/25/2008] [Indexed: 01/08/2023]
Abstract
Posterior fossa artifacts constitute a characteristic limitation of cranial CT. To identify practical benefits and drawbacks of newer CT systems with reduced collimation in routine cranial imaging, we aimed to investigate image quality, posterior fossa artifacts and parenchymal delineation in non-enhanced CT (NECT) with 1-, 4-, 16- and 64-slice scanners using standard scan protocols. We prospectively enrolled 25 consecutive patients undergoing NECT on a 64-slice CT. Three groups with 25 patients having undergone NECT on 1-, 4- and 16-slice CT machines were matched regarding age and sex. Standard routine CT parameters were used on each CT system with helical acquisition in the posterior fossa; the parameters varied regarding collimation and radiation dose. Three blinded readers independently assessed the cases regarding image quality, infra- and supratentorial artifacts and delineation of brain parenchymal structures on a five-point ordinal scale. Reading orders were randomized. A proportional odds model that accounted for the correlated nature of the data was fit using generalized estimating equations. Posterior fossa artifacts were significantly reduced, and the delineation of infratentorial brain structures was significantly improved with the thinner collimation used for the newer CT systems (p<0.001). No significant differences were observed for midbrain structures (p>0.5). The thinner collimation available on modern CT systems leads to reduced posterior fossa artifacts and to a better delineation of brain parenchyma in the posterior fossa.
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Hashimoto K, Kawashima S, Kameoka S, Akiyama Y, Honjoya T, Ejima K, Sawada K. Comparison of image validity between cone beam computed tomography for dental use and multidetector row helical computed tomography. Dentomaxillofac Radiol 2008; 36:465-71. [PMID: 18033942 DOI: 10.1259/dmfr/22818643] [Citation(s) in RCA: 67] [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: 11/05/2022] Open
Abstract
OBJECTIVES To evaluate and compare the image validity of a cone beam CT machine for dental use (3DX) and the latest medical CT system, multidetector row helical CT (MDCT). METHODS A dried right maxilla of an Asian adult was used as a phantom. It was cut from the zygomatic process towards the midline, parallel to the midline plane, into eight slices of 2 mm thickness. This phantom was imaged with the 3DX and MDCT machines. Images were evaluated by comparing them with one selected bone slice from the phantom. In this comparison, two types of MDCT images were used: one with the window level (WL) and window width (WW) suitable for observing teeth (MDCT tooth image), and the other appropriate for observing bone (MDCT bone image). Three dentists and one radiographer then used our reported subjective five-level scale to evaluate and compare images generated by the two systems in terms of validity. Cancellous bone as well as enamel, dentin, pulp cavity, periodontal ligament space, lamina dura and overall impression were evaluated. RESULTS Statistically significant differences (P<0.05) were found for almost all observation items. Our subjective evaluation clarified that 3DX was superior to MDCT in terms of image validity. Few significant intra- or interevaluator errors were found. CONCLUSIONS Our subjective evaluation of image validity clarified 3DX as being superior to MDCT. Taken together with the low skin dose we previously reported for 3DX, the results demonstrate 3DX to be beneficial for imaging diagnosis of hard tissues in the maxillofacial region.
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Affiliation(s)
- K Hashimoto
- Department of Oral and Maxillofacial Radiology, Nihon University School of Dentistry, 1-8-13, Kanda Surugadai, Tokyo 101-8310, Japan.
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TEASDALE E. Mutlidetector CT: new horizons in neurological imaging. Imaging 2007. [DOI: 10.1259/imaging/15439328] [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: 11/05/2022] Open
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28
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Rodríguez R, Calzado A, Gómez-León N, Arenas A, Cuevas A, García-Castaño B, Morán LM, Morán P, Turrero A. [Quality assessment in single-slice spiral brain CT examinations of patients with cerebrovascular accident]. Radiologia 2006; 48:147-54. [PMID: 17058636 DOI: 10.1016/s0033-8338(06)73145-9] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES Our objective was to apply quality criteria proposed by the European Commission (EC) Guidelines to the brain CT examinations for cerebrovascular accident (CVA) diagnosis at single-slice spiral CT scanners from five different hospitals in the Madrid area. MATERIAL AND METHODS A sample of 100 brain CT examinations was collected and independently reviewed by five radiologists, to determine the degree of fulfilment of image quality criteria. Dose measurements were performed to estimate the values of the CT dose indexes (CTDIw, CTDIair), the dose length product (DLP), and the effective dose (E). RESULTS Once the McNemar test was applied to the sample, the number of observers' readings was reduced to three. The quality criteria were, in general, fulfilled, since mean values of image quality score between 80% and 92% were deduced, with variation coefficients per centre in the range of 0.07-0.1. However, both visualization criteria 1.1.2 and 1.1.3 exhibited similar ranges of fulfilment (38% - 94%). The good compliance with critical reproduction criteria in the study reflected the capability of these CT scanners to create images of adequate quality, although optimisation should be achieved in some of the centres. Concerning radiation exposure, the mean values per centre of the dose quantities were in the range of 42-64 mGy for the weighted CTDI (CTDIw), 423-744 mGy x cm for DLP, and 1.1-1.9 mSv for E. CONCLUSIONS The mean values at three centres were close to but above the reference value proposed by the EC Guidelines for CTDIw (60 mGy), and lower than the corresponding reference level for DLP (1050 mGy x cm). Dose optimisation techniques focused on the adjustment of the CTDIw-related examination parameters were proposed.
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Affiliation(s)
- R Rodríguez
- Departamento de Radiología y Medicina Física, Universidad Complutense de Madrid, Madrid.
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Hernalsteen D, Cosnard G, Robert A, Grandin C, Vlassenbroek A, Duprez T. Suitability of helical multislice acquisition technique for routine unenhanced brain CT: an image quality study using a 16-row detector configuration. Eur Radiol 2006; 17:975-82. [PMID: 16912851 DOI: 10.1007/s00330-006-0360-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [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: 01/03/2006] [Revised: 04/16/2006] [Accepted: 06/12/2006] [Indexed: 11/26/2022]
Abstract
Subjective and objective image quality (IQ) criteria, radiation doses, and acquisition times were compared using incremental monoslice, incremental multislice, and helical multislice acquisition techniques for routine unenhanced brain computed tomography (CT). Twenty-four patients were examined by two techniques in the same imaging session using a 16-row CT system equipped with 0.75-width detectors. Contiguous "native" 3-mm-thick slices were reconstructed for all acquisitions from four detectors for each slice (4x0.75 mm), with one channel available per detector. Two protocols were tailored to compare: (1) one-slice vs four-slice incremental images; (2) incremental vs helical four-slice images. Two trained observers independently scored 12 subjective items of IQ. Preference for the technique was assessed by one-tailed t test and the interobserver variation by two-tailed t test. The two observers gave very close IQ scores for the three techniques without significant interobserver variations. Measured IQ parameters failed to reveal any difference between techniques, and an approximate half radiation dose reduction was obtained by using the full 16-row configuration. Acquisition times were cumulatively shortened by using the multislice and the helical modality.
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Affiliation(s)
- Danielle Hernalsteen
- Department of Radiology and Medical Imaging, Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Avenue Hippocrate, 10, 1200, Brussels, Belgium
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Hashimoto K, Kawashima S, Araki M, Iwai K, Sawada K, Akiyama Y. Comparison of image performance between cone-beam computed tomography for dental use and four-row multidetector helical CT. J Oral Sci 2006; 48:27-34. [PMID: 16617198 DOI: 10.2334/josnusd.48.27] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
The authors evaluated the imaging performance of cone-beam computed tomography (CBCT) for dental use using 3DX multi-image micro-CT (Morita Co., Kyoto, Japan) and four-row multi-detector helical computed tomography (MDCT) using an Asteion (Toshiba, Tokyo, Japan). A dried right maxillary bone was cut into eight slices 2 mm thick toward the zygomatico-palate and used as a phantom. Images of the phantom were then taken using 3DX and MDCT. The images of two bone slices were evaluated by five dentists for image quality and reproducibility of cancellous bone, as well as enamel, dentin, pulp cavity, periodontal ligament space, lamina dura and the overall image. Using the MDCT images as the standard, the 3DX images were evaluated with a subjective 5-level scale: 3 for an image equal to the MDCT image, 4 or greater for better, and 2 or lower for worse. The scores for all parameters exceeded 4 points. Maximum mean score was 4.8 for the lamina dura. Statistically significant differences were found for all items (P < 0.01). Our subjective evaluation of imaging performance clarified that 3DX was superior to MDCT. The results of this study suggest that 3DX is useful for imaging in the dental field.
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Affiliation(s)
- Koji Hashimoto
- Department of Oral and Maxillofacial Radiology, Nihon University School of Dentistry, Tokyo, Japan.
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Connor SEJ, Flis C. The contribution of high-resolution multiplanar reformats of the skull base to the detection of skull-base fractures. Clin Radiol 2005; 60:878-85. [PMID: 16039923 DOI: 10.1016/j.crad.2005.04.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [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: 01/16/2005] [Revised: 04/06/2005] [Accepted: 04/08/2005] [Indexed: 11/19/2022]
Abstract
AIM To investigate the contribution of routine review of submillimetric multiplanar reformats to the diagnosis of skull-base fractures. METHODS A prospective analysis was performed of 407 cases referred over a 6-month period for CT of the skull following cranial trauma. The reformatted 5-mm axial sections and subsequently the high-resolution multiplanar reformats (HRMPRs) were viewed on an ADW 4.1 workstation using bone windows and algorithm. All skull-base fractures and related features, recorded by the consensus of two radiologists, were classified as anatomically significant or non-significant on the basis of eight criteria. The clinical features of skull-base injury and any subsequent treatment were noted in all cases of skull-base fracture. RESULTS HRMPRs detected 80 separate skull-base fractures in 36/407 cases. Of these 80 fractures, 57 were visible on 5-mm axial sections. In 8 of the 36 cases, the significant anatomical features were only evident on review of the HRMPRs. In 6 of the 36 cases, none of the skull-base fractures was visible on 5-mm sections, but these individuals had only minor associated clinical features and no therapeutic requirements. Review of HRMPRs could have been confined to patients with skull-base fractures, abnormal intracranial and extracranial air collections or opacified mastoid air cells revealed by 5-mm axial sections. This policy would have led to the detection of 79/80 (99%) of skull-base fractures and all significant anatomical features. CONCLUSION The 5-mm axial sections demonstrated 71% of skull-base fractures and 78% of skull-base fractures with significant anatomical features, using HRMPRs as a gold standard. There were no significant clinical sequelae at short-term follow-up of those fractures only evident on HRMPRs.
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Affiliation(s)
- S E J Connor
- Neuroradiology Department, Kings College Hospital, Denmark Hill, London, UK.
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Abstract
Traumatic brain injury (TBI) is a common and potentially devastating clinical problem. Because prompt proper management of TBI sequelae can significantly alter the clinical course especially within 48 h of the injury, neuroimaging techniques have become an important part of the diagnostic work up of such patients. In the acute setting, these imaging studies can determine the presence and extent of injury and guide surgical planning and minimally invasive interventions. Neuroimaging also can be important in the chronic therapy of TBI, identifying chronic sequelae, determining prognosis, and guiding rehabilitation.
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Affiliation(s)
- Bruce Lee
- Department of Medicine, University of Pennsylvania Health System, Philadelphia, Pennsylvani 19104, USA
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Lee B, Newberg A. Neuroimaging in traumatic brain imaging. Neurotherapeutics 2005. [DOI: 10.1007/bf03206678] [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: 10/18/2022] Open
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Ertl-Wagner BB, Bruening R, Blume J, Hoffmann RT, Snyder B, Herrmann KA, Reiser MF. Prospective, multireader evaluation of image quality and vascular delineation of multislice CT angiography of the brain. Eur Radiol 2005; 15:1051-9. [PMID: 15778838 DOI: 10.1007/s00330-005-2689-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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: 11/16/2004] [Revised: 01/06/2005] [Accepted: 01/11/2005] [Indexed: 10/25/2022]
Abstract
The aim of this prospective, multireader trial was to investigate image quality and vascular delineation of cranial multislice CT angiography (MSCTA) to identify strengths and weaknesses of the method. Sixty consecutive patients underwent standardized cranial MSCTA. The mean estimated effective dose was 0.96+/-0.11 mSv. Three masked readers independently graded image quality parameters and vascular delineation on a 5-point scale. Vascular attenuation values and dose-length products were assessed quantitatively. Quantitative parameters were evaluated with a proportional odds regression model with bootstrapped standard errors to adjust the relevant standard errors for correlation within subjects and across readers. The non-parametric Wilcoxon sign-rank test was applied for quantitative measurements. Good to excellent ratings were observed regarding image quality parameters and vascular delineation. The delineation of veins was rated higher than that of arteries (OR 2.00). Smaller arterial segments were rated significantly less favorably than larger segments (OR up to 26.98). Moreover, the cavernous sinus, the C2 segment of the ICA and the communicating arteries demonstrated lower scores. Attenuation values were >240 HU and vessel-to-parenchyma ratios >7 in all vessels. Cranial MSCTA achieved high ratings regarding image quality and vascular delineation. Relative weaknesses were found in small arterial subsegments and in vessels in close topographical proximity to bone.
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Affiliation(s)
- Birgit B Ertl-Wagner
- Institute of Clinical Radiology, Klinikum Grosshadern, University of Munich, Germany.
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35
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Romano M, Mainenti PP, Imbriaco M, Amato B, Markabaoui K, Tamburrini O, Salvatore M. Multidetector row CT angiography of the abdominal aorta and lower extremities in patients with peripheral arterial occlusive disease: diagnostic accuracy and interobserver agreement. Eur J Radiol 2004; 50:303-8. [PMID: 15145492 DOI: 10.1016/s0720-048x(03)00118-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [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: 10/30/2002] [Revised: 03/24/2003] [Accepted: 03/26/2003] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the accuracy of four channel multidetector row CT angiography (MDCTA) of the abdominal aorta and lower extremities arteries compared with digital subtraction angiography (DSA). MATERIALS AND METHODS In our prospective study 42 patients with peripheral vascular occlusive disease (27 M, 15 F, age range 40-79 years) underwent MDCTA and DSA within 5 days. Images were blindly interpreted by two radiologists. Maximum intensity projections (MIP), multiplanar (MPR) reformations, three-dimensional (3D) reconstructions as well as axial images were available for analysis of MDCTA. DSA were analyzed on hard copies. RESULTS Overall sensitivity and specificity of MDCTA were 93 and 95%, respectively, with positive and negative predictive values of 90 and 97%. Overall diagnostic accuracy was 94%. Normal arterial segments and 100% occlusions were correctly identified in all cases by MDCTA. Moderately stenotic segments interpretation in the calves appeared to be more controversial, but no statistical difference in accuracy of MDCTA in the infrapopliteal district arteries was noted with respect to accuracy in the more proximal arterial bed. Good to excellent interobserver and intraobserver agreement were observed, with k values greater than 0.80. CONCLUSIONS MDCTA of the abdominal aorta and lower extremities is an accurate imaging modality in clinical practice when compared with DSA.
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Affiliation(s)
- Maurizio Romano
- Department of Surgery, University Federico II, 5, Via Pansini, 80131 Naples, Italy.
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Ertl-Wagner BB, Hoffmann RT, Bruning R, Herrmann K, Snyder B, Blume JD, Reiser MF. Multi-detector row CT angiography of the brain at various kilovoltage settings. Radiology 2004; 231:528-35. [PMID: 15044744 DOI: 10.1148/radiol.2312030543] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To investigate image quality and vascular delineation of multi-detector row computed tomographic (CT) angiography at various kilovoltage settings. MATERIALS AND METHODS Thirty patients were investigated with a standardized CT protocol, with three groups of 10 consecutive patients examined at 80, 120, and 140 kV, respectively. Three blinded readers independently evaluated images and graded image quality parameters, diagnostic confidence, and vascular delineation of intracranial arteries and veins. Vascular CT attenuation values, CT dose indices, and dose length products were assessed quantitatively. For data analysis, a Kruskal-Wallis nonparametric rank F test was used to identify trends and variables that required modeling attention. A proportional odds multinomial regression model was then fit with generalized estimating equations to account for the correlated nature of the data. RESULTS Image quality was rated higher with higher kilovoltage settings (P <.001). The severity of imaging artifacts was higher with lower kilovoltage settings (P <.001), while the subjectively rated vessel contrast was lower in the 80-kV group than in the 120-kV group and the 140-kV group (P <.05). Diagnostic confidence was higher in the 120-kV group and 140-kV group (P <.005). Vascular delineation was higher with higher kilovoltage settings for most arterial and venous structures. Differences were more significant for structures in close topographic proximity to bone and for subsegmental arteries and were less significant and, in parts, not significant for the main arterial branches and the large venous sinus. Attenuation values were higher with lower kilovoltage settings (P <.05). The mean dose length product could be reduced from 594 mGy. cm in the 140-kV group to 152 mGy.cm in the 80-kV group. CONCLUSION This multireader study of image quality and vessel delineation with cranial multi-detector row CT angiography at various kilovoltage settings demonstrated a superiority of higher voltages with most pronounced effects for vessels adjacent to bone and subsegmental arteries.
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Affiliation(s)
- Birgit B Ertl-Wagner
- Institute of Clinical Radiology, Klinikum Grosshadern, University of Munich, Marchioninistr 15, D-81377 Munich, Germany.
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Philipp MO, Funovics MA, Mann FA, Herneth AM, Fuchsjaeger MH, Grabenwoeger F, Lechner G, Metz VM. Four-channel multidetector CT in facial fractures: do we need 2 x 0.5 mm collimation? AJR Am J Roentgenol 2003; 180:1707-13. [PMID: 12760948 DOI: 10.2214/ajr.180.6.1801707] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Our aim was to optimize acquisition protocols and multiplanar reformation algorithms for the evaluation of facial fractures using multidetector CT (MDCT) and to determine whether 2 x 0.5 mm collimation is necessary. MATERIALS AND METHODS A cadaveric head with artificial blunt facial trauma was examined using a four-channel MDCT scanner. The influence of acquisition parameters (collimation, 2 x 0.5 mm, 4 x 1 mm, 4 x 2.5 mm; tube current, 120 mAs, 90 mAs, 60 mAs), image reconstruction algorithms (standard vs ultra-high-resolution modes; reconstructed slice thicknesses, 0.5 mm, 1 mm, 3 mm; increment, 0.3 mm, 0.6 mm, 1.5 mm), and reformation algorithms (slice thicknesses, 0.5 mm, 1 mm, 3 mm; overlap, 0.5 mm, 1 mm, 3 mm) on detectability of facial fractures in multiplanar reformations with MDCT was analyzed. RESULTS Fracture detection was significantly higher with thin multiplanar reformations (0.5 and 0.5 mm, 1 and 0.5 mm, and 1 and 1 mm) (p < or = 0.014) acquired with 2 x 0.5 mm collimation (p < or = 0.046) in ultra-high-resolution mode (p < 0.0005) with 120 mAs (p < or = 0.025). Interobserver variability showed very good agreement (kappa > or = 0.942). Non-ultra-high-resolution mode, lower milliampere-seconds, and thick multiplanar reformations (3 and 0.5 mm, 3 and 1 mm, and 3 and 0.5 mm) showed significantly decreased fracture detectability. CONCLUSION Although thin multiplanar reformations obtained from thin collimation (2 x 0.5 mm) are statistically superior for the detection of subtle fractures, 4 x 1 mm collimation is sufficient for routine diagnostic evaluation. Ultra-high-resolution mode with 120 mAs is mandatory for detection of clinically relevant fractures.
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Affiliation(s)
- Marcel O Philipp
- Department of Radiology, Division of Surgery, University of Vienna Medical School, General Hospital Vienna, Waehringer Guertel 18-20, Austria
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Abstract
The development of thrombolytic and neuroprotective agents for the treatment of acute stroke has created an imperative for improved imaging techniques in the assessment of acute stroke. Five cases are presented to illustrate the value of perfusion CT in the evaluation of suspected acute stroke. To obtain the perfusion data, a rapid series of images was acquired without table movement following a bolus of contrast medium. Cerebral blood flow, cerebral blood volume and mean transit time were determined by mathematically modelling the temporal changes in contrast enhancement in the brain and vascular system. Pixel-by-pixel analysis allowed generation of perfusion maps. In two cases, CT-perfusion imaging usefully excluded acute stroke, including one patient in whom a low-density area on conventional CT was subsequently proven to be tumour. Cerebral ischaemia was confirmed in three cases, one with an old and a new infarction, one with a large conventional CT abnormality but only a small perfusion defect, and one demonstrating infarct and penumbra. Perfusion CT offers the ability to positively identify patients with non-haemorrhagic stroke in the presence of a normal conventional CT, to select those cases where thrombolysis is appropriate, and to provide an indication for prognosis.
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Affiliation(s)
- C J Keith
- Southern X-ray Clinics, School of Physical Sciences, Queensland University of Technology, Brisbane, Australia.
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Abstract
Traumatic intracranial hemorrhage is a leading cause of morbidity and mortality in the United States. CT remains the primary imaging modality for initial evaluation of patients who have sustained head trauma. MR imaging, which has always been important for the evaluation of subacute and chronic head trauma, has been gaining popularity and recognition as an alternative primary imaging modality.
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Affiliation(s)
- Robert J Young
- Department of Radiology, Saint Luke's Roosevelt Hospital Center, 1000 Tenth Avenue, New York, NY 10019, USA.
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