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Shinohara Y, Ohmura T, Sasaki F, Sato Y, Inomata T, Itoh T, Kinoshita T. Dual-Energy Computed Tomography Virtual Noncalcium Imaging of Intracranial Arteries in Acute Ischemic Stroke: Differentiation Between Acute Thrombus and Calcification. J Comput Assist Tomogr 2024:00004728-990000000-00315. [PMID: 38657159 DOI: 10.1097/rct.0000000000001623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
OBJECTIVE Hyperdense artery sign (HAS) on noncontrast brain computed tomography (CT) indicates an acute thrombus within the cerebral artery. It is a valuable imaging biomarker for diagnosing large-vessel occlusion; however, its identification may be challenging with the presence of vascular calcification. Dual-energy CT virtual noncalcium (VNCa) imaging using a 3-material decomposition algorithm is helpful for differentiating between calcification and hemorrhage. This study aimed to clarify the potential of VNCa imaging for differentiating HAS from vascular calcification. METHODS Patients with acute ischemic stroke and large-vessel occlusion identified on MR angiography, who also underwent noncontrast dual-energy CT, were included. The 80 kV/Sn 140 kV mixed images, with a weighting factor of 0.4, were considered 120 kVp-equivalent images. Postprocessing using a 3-material decomposition algorithm to differentiate between calcium (Ca), cerebrospinal fluid, and hemorrhage was performed via a commercially available 3-dimensional workstation. A mixed image, VNCa image, color-coded Ca image, and color-coded Ca image with VNCa image overlay (color-coded Ca-overlay image) were obtained, and axial reconstruction with a 1-mm slice thickness was performed for each image type. Two experienced neuroradiologists conducted imaging evaluations in consensus. RESULTS Thirty-four patients (mean age, 76.0 years; 21 male and 13 female patients) were included. The mixed and VNCa images revealed an HAS (indicating an acute clot) corresponding to the large-vessel occlusion site in 30 patients. Among them, the VNCa and color-coded Ca-overlay images enabled clear differentiation between the acute thrombus and adjacent vessel wall calcification in 5 patients. Among the other 4 patients, the VNCa, Ca-overlay, and Ca images identified calcified cerebral emboli in the M1 segment in 1 patient. For the other 3 patients, no high attenuation corresponding to magnetic resonance angiography findings was observed in any of the mixed, VNCa, Ca-overlay, or Ca images. CONCLUSIONS VNCa and color-coded Ca-overlay images obtained via dual-energy brain CT enabled differentiation of acute thrombus from vessel wall calcification and calcified cerebral emboli in patients with acute ischemic stroke.
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Affiliation(s)
- Yuki Shinohara
- From the Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, Akita, Japan
| | - Tomomi Ohmura
- From the Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, Akita, Japan
| | - Fumiaki Sasaki
- From the Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, Akita, Japan
| | - Yuichiro Sato
- From the Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, Akita, Japan
| | - Takato Inomata
- From the Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, Akita, Japan
| | - Toshihide Itoh
- CT Research and Collaboration Department, Diagnostic Imaging Division, Siemens Healthcare K.K., Tokyo, Japan
| | - Toshibumi Kinoshita
- From the Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, Akita, Japan
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2
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May C, Sodickson A. Leveraging Dual-Energy Computed Tomography to Improve Emergency Radiology Practice. Radiol Clin North Am 2023; 61:1085-1096. [PMID: 37758358 DOI: 10.1016/j.rcl.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Dual-energy computed tomography affords emergency radiologists with important tools to aid in the detection and discrimination of commonly encountered ED pathologies. In doing so, it can increase the speed of diagnosis and diagnostic certainty while sparing patients potentially unnecessary downsteam workups and radiation exposure. This article demonstrates these clinical benefits through a case-based approach.
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Affiliation(s)
- Craig May
- Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA.
| | - Aaron Sodickson
- Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
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3
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Cademartiri F, Meloni A, Pistoia L, Degiorgi G, Clemente A, De Gori C, Positano V, Celi S, Berti S, Emdin M, Panetta D, Menichetti L, Punzo B, Cavaliere C, Bossone E, Saba L, Cau R, Grutta LL, Maffei E. Dual Source Photon-Counting Computed Tomography-Part II: Clinical Overview of Neurovascular Applications. J Clin Med 2023; 12:jcm12113626. [PMID: 37297821 DOI: 10.3390/jcm12113626] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 06/12/2023] Open
Abstract
Photon-counting detector (PCD) is a novel computed tomography detector technology (photon-counting computed tomography-PCCT) that presents many advantages in the neurovascular field, such as increased spatial resolution, reduced radiation exposure, and optimization of the use of contrast agents and material decomposition. In this overview of the existing literature on PCCT, we describe the physical principles, the advantages and the disadvantages of conventional energy integrating detectors and PCDs, and finally, we discuss the applications of the PCD, focusing specifically on its implementation in the neurovascular field.
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Affiliation(s)
| | - Antonella Meloni
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Laura Pistoia
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Giulia Degiorgi
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Alberto Clemente
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Carmelo De Gori
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Vincenzo Positano
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Simona Celi
- BioCardioLab, Department of Bioengineering, Fondazione Monasterio/CNR, 54100 Massa, Italy
| | - Sergio Berti
- Cardiology Unit, Ospedale del Cuore, Fondazione Monasterio/CNR, 54100 Massa, Italy
| | - Michele Emdin
- Department of Cardiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Daniele Panetta
- Institute of Clinical Physiology, National Council of Research, 56124 Pisa, Italy
| | - Luca Menichetti
- Institute of Clinical Physiology, National Council of Research, 56124 Pisa, Italy
| | - Bruna Punzo
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy
| | - Carlo Cavaliere
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy
| | - Luca Saba
- Department of Radiology, University Hospital, 09042 Monserrato, Italy
| | - Riccardo Cau
- Department of Radiology, University Hospital, 09042 Monserrato, Italy
| | - Ludovico La Grutta
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties-ProMISE, Department of Radiology, University Hospital "P. Giaccone", 90127 Palermo, Italy
| | - Erica Maffei
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
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Katsuyama Y, Kojima T, Shirasaka T, Kondo M, Kato T. Characteristics of the deep learning-based virtual monochromatic image with fast kilovolt-switching CT: a phantom study. Radiol Phys Technol 2023; 16:77-84. [PMID: 36583827 DOI: 10.1007/s12194-022-00695-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/19/2022] [Accepted: 12/23/2022] [Indexed: 12/31/2022]
Abstract
PURPOSE We assessed the physical properties of virtual monochromatic images (VMIs) obtained with different energy levels in various contrast settings and radiation doses using deep learning-based spectral computed tomography (DL-Spectral CT) and compared the results with those from single-energy CT (SECT) imaging. MATERIALS AND METHODS A Catphan® 600 phantom was scanned by DL-Spectral CT at various radiation doses. We reconstructed the VMIs obtained at 50, 70, and 100 keV. SECT (120 kVp) images were acquired at the same radiation doses. The standard deviations of the CT number and noise power spectrum (NPS) were calculated for noise characterization. We evaluated the spatial resolution by determining the 10% task-based transfer function (TTF) level, and we assessed the task-based detectability index (d'). RESULTS Regardless of the radiation dose, the noise was the lowest at 70 keV VMI. The NPS showed that the noise amplitude at all spatial frequencies was the lowest among other VMI and 120 kVp images. The spatial resolution was higher for 70 keV VMI compared to the other VMIs, except for high-contrast objects. The d' of 70 keV VMI was the highest among the VMI and 120 kVp images at all radiation doses and contrast settings. The d' of the 70 keV VMIs at the minimum dose was higher than that at the maximum dose in any other image. CONCLUSION The physical properties of the DL-Spectral CT VMIs varied with the energy level. The 70 keV VMI had the highest detectability by far among the VMI and 120-kVp images. DL-Spectral CT may be useful to reduce radiation doses.
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Affiliation(s)
- Yuna Katsuyama
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan.
| | - Tsukasa Kojima
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan.,Department of Health Sciences, Graduate school of Medical Sciences, Kyushu University, Fukuoka, Fukuoka, Japan
| | - Takashi Shirasaka
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan
| | - Masatoshi Kondo
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan
| | - Toyoyuki Kato
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan
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5
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Yu HS, Keraliya A, Chakravarti S, Uyeda JW. Multienergy Computed Tomography Applications. Radiol Clin North Am 2023; 61:23-35. [DOI: 10.1016/j.rcl.2022.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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6
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Multi-Energy CT Applications. Radiol Clin North Am 2023; 61:1-21. [DOI: 10.1016/j.rcl.2022.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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7
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Zhang Y, Hu J, Li L, Zhao Y. Application of Computer-Based Simulation Teaching Combined with PBL in Colorectal Tumor Hemorrhage. Emerg Med Int 2022; 2022:1251388. [PMID: 36119913 PMCID: PMC9481396 DOI: 10.1155/2022/1251388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/08/2022] [Accepted: 08/18/2022] [Indexed: 11/17/2022] Open
Abstract
Objective This paper aims to explore the use of computer-based simulation teaching combined with PBL in colorectal tumor bleeding. Methods The outpatient department organized 21 nursing staffs to conduct computer simulation combined with PBL teaching, compared emergency theory and skill scores, and investigated the recognition of computer simulation teaching combined with PBL. Results The scores of theoretical knowledge examination before training were (84.31 ± 6.39) and (92.59 ± 2.93) after training; the scores of treatment skills examination were (85.69 ± 6.15) and (95.43 ± 2.88) after training; the scores of comprehensive treatment skills before training were (76.6 ± 6.31) and (91.43 ± 2.3) after training. The results of the questionnaires showed that the nurses were more agreeable to the new teaching methods and were able to complete the tasks in strict accordance with the requirements, ultimately achieving a level of satisfaction with their progress. Conclusion Computer simulation teaching combined with PBL can deepen general practitioners' understanding of knowledge, improve practical ability, and provide a clinical basis for improving patient resuscitation in specialized oncology hospitals.
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Affiliation(s)
- Yanling Zhang
- Medical Oncology Department of Thoracic Cancer, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang 110042, China
| | - Jinyan Hu
- Nursing Department, Chifeng Municipal Hospital, Chifeng 024000, China
| | - Lingling Li
- Medical Oncology Department of Thoracic Cancer, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang 110042, China
| | - Yunpeng Zhao
- Medical Oncology Department of Thoracic Cancer, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang 110042, China
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8
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Tran NA, Sodickson AD, Gupta R, Potter CA. Clinical applications of dual-energy computed tomography in neuroradiology. Semin Ultrasound CT MR 2022; 43:280-292. [PMID: 35738814 DOI: 10.1053/j.sult.2022.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dual-energy computed tomography (DECT) has developed into a robust set of techniques with increasingly validated clinical applications in neuroradiology. We review some of the most common applications in neuroimaging along with demonstrative case examples that showcase the use of this technology in intracranial hemorrhage, stroke imaging, trauma imaging, artifact reduction, and tumor characterization.
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Affiliation(s)
- Ngoc-Anh Tran
- Department of Radiology, Brigham and Women's Hospital, Boston, MA.
| | - Aaron D Sodickson
- Division of Emergency Medicine, Department of Radiology, Brigham and Women's Hospital, Boston, MA
| | - Rajiv Gupta
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Boston, MA
| | - Christopher A Potter
- Division of Emergency Medicine, Department of Radiology, Brigham and Women's Hospital, Boston, MA; Division of Neuroradiology, Department of Radiology, Brigham and Women's Hospital, Boston, MA
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9
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Gaddam DS, Dattwyler M, Fleiter TR, Bodanapally UK. Principles and Applications of Dual Energy Computed Tomography in Neuroradiology. Semin Ultrasound CT MR 2021; 42:418-433. [PMID: 34537112 DOI: 10.1053/j.sult.2021.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dual-energy computed tomography (DE CT) is a promising tool with many current and evolving applications. Available DE CT scanners usually consist of one or two tubes, or use layered detectors for spectral separation. Most DE CT scanners can be used in single energy or dual-energy mode, except for the layered detector scanners that always acquire data in dual-energy mode. However, the layered detector scanners can retrospectively integrate the data from two layers to obtain conventional single energy images. DE CT mode enables generation of virtual monochromatic images, blended images, iodine quantification, improving conspicuity of iodinated contrast enhancement, and material decomposition maps or more sophisticated quantitative analysis not possible with conventional SE CT acquisition with an acceptable or even lower dose than the SE CT. This article reviews the basic principles of dual-energy CT and highlights many of its clinical applications in the evaluation of neurological conditions.
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Affiliation(s)
- Durga Sivacharan Gaddam
- Department of Diagnostic Radiology and Nuclear Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD
| | - Matthew Dattwyler
- Department of Diagnostic Radiology and Nuclear Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD
| | - Thorsten R Fleiter
- Department of Diagnostic Radiology and Nuclear Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD
| | - Uttam K Bodanapally
- Department of Diagnostic Radiology and Nuclear Medicine, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD.
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10
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D'Angelo T, Albrecht MH, Caudo D, Mazziotti S, Vogl TJ, Wichmann JL, Martin S, Yel I, Ascenti G, Koch V, Cicero G, Blandino A, Booz C. Virtual non-calcium dual-energy CT: clinical applications. Eur Radiol Exp 2021; 5:38. [PMID: 34476640 PMCID: PMC8413416 DOI: 10.1186/s41747-021-00228-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 06/11/2021] [Indexed: 12/15/2022] Open
Abstract
Dual-energy CT (DECT) has emerged into clinical routine as an imaging technique with unique postprocessing utilities that improve the evaluation of different body areas. The virtual non-calcium (VNCa) reconstruction algorithm has shown beneficial effects on the depiction of bone marrow pathologies such as bone marrow edema. Its main advantage is the ability to substantially increase the image contrast of structures that are usually covered with calcium mineral, such as calcified vessels or bone marrow, and to depict a large number of traumatic, inflammatory, infiltrative, and degenerative disorders affecting either the spine or the appendicular skeleton. Therefore, VNCa imaging represents another step forward for DECT to image conditions and disorders that usually require the use of more expensive and time-consuming techniques such as magnetic resonance imaging, positron emission tomography/CT, or bone scintigraphy. The aim of this review article is to explain the technical background of VNCa imaging, showcase its applicability in the different body regions, and provide an updated outlook on the clinical impact of this technique, which goes beyond the sole improvement in image quality.
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Affiliation(s)
- Tommaso D'Angelo
- Department of Biomedical Sciences and Morphological and Functional Imaging, University Hospital Messina, Messina, Italy
| | - Moritz H Albrecht
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany.
| | - Danilo Caudo
- Department of Biomedical Sciences and Morphological and Functional Imaging, University Hospital Messina, Messina, Italy
| | - Silvio Mazziotti
- Department of Biomedical Sciences and Morphological and Functional Imaging, University Hospital Messina, Messina, Italy
| | - Thomas J Vogl
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Julian L Wichmann
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Simon Martin
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Ibrahim Yel
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Giorgio Ascenti
- Department of Biomedical Sciences and Morphological and Functional Imaging, University Hospital Messina, Messina, Italy
| | - Vitali Koch
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Giuseppe Cicero
- Department of Biomedical Sciences and Morphological and Functional Imaging, University Hospital Messina, Messina, Italy
| | - Alfredo Blandino
- Department of Biomedical Sciences and Morphological and Functional Imaging, University Hospital Messina, Messina, Italy
| | - Christian Booz
- Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany
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11
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Campo CA, Czajkowski B, Sodickson AD. Advantages of Colour-Coded Dual-Energy CT Venography in Emergency Neuroimaging. Br J Radiol 2021; 94:20201309. [PMID: 34379491 DOI: 10.1259/bjr.20201309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The objective of this Pictorial Review is to describe the use of colour-coded Dual-Energy CT (DECT) to aid in the interpretation of CT Venography (CTV) of the head for emergent indications. We describe a DE CTV acquisition and post-processing technique that can be readily incorporated into clinical workflow. Colour-coded DE CTV may aid the identification and characterization of dural venous sinus abnormalities and other cerebrovascular pathologies, which can improve diagnostic confidence in emergent imaging settings.
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Affiliation(s)
- Camilo A Campo
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.,Harvard Medical School, Boston, MA, USA
| | - Bryan Czajkowski
- Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA
| | - Aaron D Sodickson
- Harvard Medical School, Boston, MA, USA.,Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA
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12
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Schellingerhout D, Jacobsen M, Le Roux L, Johnson J, Baladandayuthapani V, Hwang KP, Hazle J, Schomer D, Cody D. The Calcium Versus Hemorrhage Trial: Developing Diagnostic Criteria for Chronic Intracranial Susceptibility Lesions Using Single-Energy Computed Tomography, Dual-Energy Computed Tomography, and Quantitative Susceptibility Mapping. Invest Radiol 2021; 56:385-393. [PMID: 33534507 DOI: 10.1097/rli.0000000000000758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Chronic susceptibility lesions in the brain can be either hemorrhagic (potentially dangerous) or calcific (usually not dangerous) but are difficult to discriminate on routine imaging. We proposed to develop quantitative diagnostic criteria for single-energy computed tomography (SECT), dual-energy computed tomography (DECT), and quantitative susceptibility mapping (QSM) to distinguish hemorrhage from calcium. MATERIALS AND METHODS Patients with positive susceptibility lesions on routine T2*-weighted magnetic resonance of the brain were recruited into this prospective imaging clinical trial, under institutional review board approval and with informed consent. The SECT, DECT, and QSM images were obtained, the lesions were identified, and the regions of interest were defined, with the mean values recorded. Criteria for quantitative interpretation were developed on the first 50 patients, and then applied to the next 45 patients. Contingency tables, scatter plots, and McNemar test were applied to compare classifiers. RESULTS There were 95 evaluable patients, divided into a training set of 50 patients (328 lesions) and a validation set of 45 patients (281 lesions). We found the following classifiers to best differentiate hemorrhagic from calcific lesions: less than 68 Hounsfield units for SECT, calcium level of less than 15 mg/mL (material decomposition value) for DECT, and greater than 38 ppb for QSM. There was general mutual agreement among the proposed criteria. The proposed criteria outperformed the current published criteria. CONCLUSIONS We provide the updated criteria for the classification of chronic positive susceptibility brain lesions as hemorrhagic versus calcific for each major clinically available imaging modality. These proposed criteria have greater internal consistency than the current criteria and should likely replace it as gold standard.
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Affiliation(s)
| | | | - Lucia Le Roux
- Cancer Systems Imaging, MD Anderson Cancer Center, Houston, TX
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13
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Ghoshal S, El Husseini N. Accelerated Mineralization as a Mimic of Hemorrhagic Conversion. Neurol Clin Pract 2021; 11:e33-e34. [PMID: 33968489 DOI: 10.1212/cpj.0000000000000764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 10/01/2019] [Indexed: 11/15/2022]
Affiliation(s)
- Shivani Ghoshal
- Department of Neurology, Wake Forest School of Medicine, Winston-Salem, NC
| | - Nada El Husseini
- Department of Neurology, Wake Forest School of Medicine, Winston-Salem, NC
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14
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Mangesius S, Grams AE. Dual energy computed tomomgraphy in acute stroke, where are we and where are we going? J Neuroradiol 2021; 48:71-74. [PMID: 33607169 DOI: 10.1016/j.neurad.2021.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 02/11/2021] [Accepted: 02/13/2021] [Indexed: 12/11/2022]
Affiliation(s)
- S Mangesius
- Department of Neuroradiology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
| | - A E Grams
- Department of Neuroradiology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
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Abstract
The introduction of photon-counting detectors is expected to be the next major breakthrough in clinical x-ray computed tomography (CT). During the last decade, there has been considerable research activity in the field of photon-counting CT, in terms of both hardware development and theoretical understanding of the factors affecting image quality. In this article, we review the recent progress in this field with the intent of highlighting the relationship between detector design considerations and the resulting image quality. We discuss detector design choices such as converter material, pixel size, and readout electronics design, and then elucidate their impact on detector performance in terms of dose efficiency, spatial resolution, and energy resolution. Furthermore, we give an overview of data processing, reconstruction methods and metrics of imaging performance; outline clinical applications; and discuss potential future developments.
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Affiliation(s)
- Mats Danielsson
- Department of Physics, KTH Royal Institute of Technology, AlbaNova University Center, SE-106 91 Stockholm, Sweden. Prismatic Sensors AB, AlbaNova University Center, SE-106 91 Stockholm, Sweden
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16
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Intracranial calcifications in childhood: Part 1. Pediatr Radiol 2020; 50:1424-1447. [PMID: 32734340 DOI: 10.1007/s00247-020-04721-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/03/2020] [Accepted: 05/12/2020] [Indexed: 12/30/2022]
Abstract
This article is the first of a two-part series on intracranial calcification in childhood. Intracranial calcification can be either physiological or pathological. Physiological intracranial calcification is not an expected neuroimaging finding in the neonatal or infantile period but occurs, as children grow older, in the pineal gland, habenula, choroid plexus and occasionally the dura mater. Pathological intracranial calcification can be broadly divided into infectious, congenital, endocrine/metabolic, vascular and neoplastic. The main goals in Part 1 are to discuss the chief differences between physiological and pathological intracranial calcification, to discuss the histological characteristics of intracranial calcification and how intracranial calcification can be detected across neuroimaging modalities, to emphasize the importance of age at presentation and intracranial calcification location, and to propose a comprehensive neuroimaging approach toward the differential diagnosis of the causes of intracranial calcification. Finally, in Part 1 the authors discuss the most common causes of infectious intracranial calcification, especially in the neonatal period, and congenital causes of intracranial calcification. Various neuroimaging modalities have distinct utilities and sensitivities in the depiction of intracranial calcification. Age at presentation, intracranial calcification location, and associated neuroimaging findings are useful information to help narrow the differential diagnosis of intracranial calcification. Intracranial calcification can occur in isolation or in association with other neuroimaging features. Intracranial calcification in congenital infections has been associated with clastic changes, hydrocephalus, chorioretinitis, white matter abnormalities, skull changes and malformations of cortical development. Infections are common causes of intracranial calcification, especially neonatal TORCH (toxoplasmosis, other [syphilis, varicella-zoster, parvovirus B19], rubella, cytomegalovirus and herpes) infections.
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Calcified brain metastases may be more frequent than normally considered. Eur Radiol 2020; 31:650-657. [PMID: 32812176 PMCID: PMC7813689 DOI: 10.1007/s00330-020-07164-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/04/2020] [Accepted: 08/06/2020] [Indexed: 11/20/2022]
Abstract
Objectives To verify the incidence of calcified brain metastases (CBM), illustrating the different presentation patterns and histology of primary tumor. Methods A series of 1002 consecutive brain computed tomography (CT) scans of patients with known primary tumors was retrospectively assessed. CBM were defined by the presence of calcification within intra-axial-enhancing lesions; identification of CBM was based on visual examination and ROI analysis (> 85 Hounsfield units). Also, calcifications in the primary tumor of all patients with brain metastases were evaluated. In CBM patients, we investigated the type of calcifications (punctate, nodular, cluster, ring, coarse), the histology of primary tumor, and if a previous RT was performed. Results Among 190 (18.9%) patients with brain metastatic disease, 34 presented with CBM (17.9%). Sixteen patients were previously treated with RT, while 18 presented calcifications ab initio (9.5% of all brain metastases). The majority of patients with CBM had a primitive lung adenocarcinoma (56%), followed by breast ductal invasive carcinoma (20%) and small cell lung carcinoma (11.8%). CBM were single in 44.1% of patients and multiple in 55.9%. With regard to the type of calcifications, the majority of CBM were punctate, without specific correlations between calcification type and histology of primary tumor. No patients with ab initio CBM had calcifications in primary tumor. Conclusion In conclusion, our data show that CBM are more common than usually thought, showing an incidence of 9.5% ab initio in patients with brain metastases. This study underlines that neuroradiologists should not overlook intraparenchymal brain calcifications, especially in oncologic patients. Key Points • Among the differential diagnosis of brain intraparenchymal calcifications, metastases are considered uncommon and found predominantly in patients treated with radiotherapy (RT). • Our data show that CBM are more common than usually thought, showing an incidence of 9.5% ab initio in patients with brain metastases. • A proportion of intraparenchymal brain calcifications, especially in oncologic patients, might represent evolving lesions and neuroradiologists should not overlook them to avoid a delay in diagnosis and treatment.
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Dual-energy CT for differentiating acute intracranial hemorrhage from contrast staining or calcification: a meta-analysis. Neuroradiology 2020; 62:1617-1626. [PMID: 32621024 DOI: 10.1007/s00234-020-02486-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/22/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE This study aimed to comprehensively evaluate the diagnostic performance of dual-energy CT (DECT) for differentiating acute intracranial hemorrhage (ICH) from contrast staining or small calcifications via a systematic review and meta-analysis. METHODS The PubMed-MEDLINE, EMBASE, and Cochrane Library databases were searched up to November 10, 2019. Original studies (prospective or retrospective cohort studies) with the primary aim of detecting ICH using DECT were selected. The diagnostic performance of DECT was assessed using bivariate and hierarchical summary receiver operating characteristic models. Quality assessment was performed according to the Quality Assessment of Diagnostic Accuracy Studies-2, while between-study heterogeneity was assessed using Higgins' inconsistency index (I2). To explore heterogeneity, subgroup meta-regression analyses were performed. Deeks' funnel plot asymmetry test was used for assessing publication bias. RESULTS Nine studies comprising 402 patients with 453 lesions were included for data synthesis. The overall pooled sensitivity and specificity of DECT for ICH detection were 96% (95% CI, 77-99%) and 98% (95 CI, 93%-100%), respectively. Substantial and moderate between-study heterogeneities were observed for sensitivity (I2 = 90.3%) and specificity (I2 = 57.9%), respectively. In meta-regression analysis, type of cohort affected heterogeneity-studies including only stroke patients showed lower sensitivity (43.5% vs. 94.2%) but higher specificity (98.7% vs. 92.6%) than those with mixed etiologies (P < 0.001). Deeks' funnel plot asymmetry test revealed publication bias (P = 0.020). CONCLUSION DECT demonstrated excellent diagnostic performance in terms of differentiating acute ICH from contrast staining and small calcifications. However, publication bias suggests the possibility of overestimated diagnostic performance, warranting large-scale, prospective cohort studies.
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McCollough CH, Boedeker K, Cody D, Duan X, Flohr T, Halliburton SS, Hsieh J, Layman RR, Pelc NJ. Principles and applications of multienergy CT: Report of AAPM Task Group 291. Med Phys 2020; 47:e881-e912. [DOI: 10.1002/mp.14157] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 02/11/2020] [Accepted: 03/10/2020] [Indexed: 12/14/2022] Open
Affiliation(s)
| | - Kirsten Boedeker
- Canon (formerly Toshiba) Medical Systems Corporation 1440 Warnall Ave Los Angeles CA 90024 USA
| | - Dianna Cody
- University of Texas, M.D. Anderson Cancer Center 7163 Spanish Grant Galveston TX 77554‐7756 USA
| | - Xinhui Duan
- Southwestern Medical Center University of Texas 5323 Harry Hines Blvd Dallas TX 75390‐9071 USA
| | - Thomas Flohr
- Siemens Healthcare GmbH Siemensstr. 3 Forchheim BY 91031 Germany
| | | | - Jiang Hsieh
- GE Healthcare Technologies 3000 N. Grandview Blvd. W-1190 Waukesha WI 53188 USA
| | - Rick R. Layman
- University of Texas, M.D. Anderson Cancer Center 7163 Spanish Grant Galveston TX 77554‐7756 USA
| | - Norbert J. Pelc
- Stanford University 443 Via Ortega, Room 203 Stanford CA 94305‐4125 USA
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Rindler RS, Allen JW, Barrow JW, Pradilla G, Barrow DL. Neuroimaging of Intracerebral Hemorrhage. Neurosurgery 2020; 86:E414-E423. [DOI: 10.1093/neuros/nyaa029] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 12/28/2019] [Indexed: 02/05/2023] Open
Abstract
AbstractIntracerebral hemorrhage (ICH) accounts for 10% to 20% of strokes worldwide and is associated with high morbidity and mortality rates. Neuroimaging is indispensable for rapid diagnosis of ICH and identification of the underlying etiology, thus facilitating triage and appropriate treatment of patients. The most common neuroimaging modalities include noncontrast computed tomography (CT), CT angiography (CTA), digital subtraction angiography, and magnetic resonance imaging (MRI). The strengths and disadvantages of each modality will be reviewed. Novel technologies such as dual-energy CT/CTA, rapid MRI techniques, near-infrared spectroscopy, and automated ICH detection hold promise for faster pre- and in-hospital ICH diagnosis that may impact patient management.
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Affiliation(s)
- Rima S Rindler
- Department of Neurosurgery, Emory University Hospital, Atlanta, Georgia
| | - Jason W Allen
- Department of Radiology and Imaging Sciences, Emory University Hospital, Atlanta, Georgia
| | - Jack W Barrow
- Mercer University School of Medicine, Savannah, Georgia
| | - Gustavo Pradilla
- Department of Neurosurgery, Emory University Hospital, Atlanta, Georgia
| | - Daniel L Barrow
- Department of Neurosurgery, Emory University Hospital, Atlanta, Georgia
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Kotsenas AL. Using Dual-Energy CT to Identify Small Foci of Hemorrhage in the Emergency Setting. Radiology 2020; 294:139-140. [DOI: 10.1148/radiol.2019192258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Amy L. Kotsenas
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55902
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Wiggins WF, Potter CA, Sodickson AD. Dual-Energy CT to Differentiate Small Foci of Intracranial Hemorrhage from Calcium. Radiology 2019; 294:129-138. [PMID: 31687919 DOI: 10.1148/radiol.2019190792] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Background Diagnostic uncertainty in CT of possible intracranial hemorrhage requires short-interval follow-up imaging, resulting in reduced efficiency of care and higher costs. Purpose To quantify the diagnostic performance of dual-energy CT versus simulated single-energy CT in the differentiation of small foci of intracranial hemorrhage from calcium. Materials and Methods Images from consecutive unenhanced dual-energy CT of the head in patients from a single emergency department obtained from December 2014 to April 2016 were reviewed retrospectively for hyperattenuating intracranial foci. Ground truth was established from reference standard comparison CT or MRI. Foci were divided into development and test sets. Development set foci regions of interest were used to derive candidate CT attenuation thresholds for virtual noncalcium (VNCa) and calcium images. Test set foci were used for threshold validation, and diagnostic performance and confidence were evaluated for two readers blinded to final diagnosis. Statistical comparisons were made with exact binomial tests or repeated-measures analysis of variance. Results The study included 137 patients (65 years ± 17; 70 men) with 146 foci. Foci were divided into a development set (n = 105) and a test set (n = 41). Quantitative analysis of the development set produced candidate thresholds of 44 HU for VNCa images and 7 HU for calcium-only images, yielding diagnostic accuracies for the test set of 88% (36 of 41 foci; 95% confidence interval [CI]: 78%, 98%) and 95% (39 of 41 foci; 95% CI: 88%, 100%), respectively. Dual-energy CT improved reader accuracy from 90% (reader 1, 37 of 41 foci; 95% CI: 81%, 99%) and 93% (reader 2, 38 of 41 foci; 95% CI: 85%, 100%) to 100% (both readers, 41 of 41 foci; 95% CI: 100%, 100%). Diagnostic confidence (classifications rated as "certain") increased from 71% (29 of 41 foci; 95% CI: 57%, 85%) to 90% (37 of 41 foci; 95% CI: 81%, 99%) for reader 1 (P = .019) and from 46% (19 of 41 foci; 95% CI: 31%, 62%) to 85% (35 of 41 foci; 95% CI: 75%, 96%) for reader 2 (P = .0001). Conclusion Dual-energy CT showed high diagnostic performance in the differentiation of small foci of intracranial hemorrhage from calcium and improved diagnostic accuracy and confidence in the initial evaluation of suspected hemorrhage. © RSNA, 2019 See also the editorial by Kotsenas in this issue.
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Affiliation(s)
- Walter F Wiggins
- From the Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass
| | - Christopher A Potter
- From the Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass
| | - Aaron D Sodickson
- From the Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass
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Quantifying effects of radiotherapy-induced microvascular injury; review of established and emerging brain MRI techniques. Radiother Oncol 2019; 140:41-53. [PMID: 31176207 DOI: 10.1016/j.radonc.2019.05.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/16/2019] [Accepted: 05/17/2019] [Indexed: 12/17/2022]
Abstract
Microvascular changes are increasingly recognised not only as primary drivers of radiotherapy treatment response in brain tumours, but also as an important contributor to short- and long-term (cognitive) side effects arising from irradiation of otherwise healthy brain tissue. As overall survival of patients with brain tumours is increasing, monitoring long-term sequels of radiotherapy-induced microvascular changes in the context of their potential predictive power for outcome, such as cognitive disability, has become increasingly relevant. Ideally, radiotherapy-induced significant microvascular changes in otherwise healthy brain tissue should be identified as early as possible to facilitate adaptive radiotherapy and to proactively start treatment to minimise the influence on these side-effects on the final outcome. Although MRI is already known to be able to detect significant long-term radiotherapy induced microvascular effects, more recently advanced MR imaging biomarkers reflecting microvascular integrity and function have been reported and might provide a more accurate and earlier detection of microvascular changes. However, the use and validation of both established and new techniques in the context of monitoring early and late radiotherapy-induced microvascular changes in both target-tissue and healthy tissue currently are minimal at best. This review aims to summarise the performance and limitations of existing methods and future opportunities for detection and quantification of radiotherapy-induced microvascular changes, as well as the relation of these findings with key clinical parameters.
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Foti G, Beltramello A, Minerva G, Catania M, Guerriero M, Albanese S, Carbognin G. Identification of residual–recurrent cholesteatoma in operated ears: diagnostic accuracy of dual-energy CT and MRI. Radiol Med 2019; 124:478-486. [DOI: 10.1007/s11547-019-00997-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 01/24/2019] [Indexed: 10/27/2022]
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25
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Yun SY, Heo YJ, Jeong HW, Baek JW, Choo HJ, Shin GW, Kim ST, Jeong YG, Lee JY, Jung HS. Dual-energy CT angiography-derived virtual non-contrast images for follow-up of patients with surgically clipped aneurysms: a retrospective study. Neuroradiology 2019; 61:747-755. [DOI: 10.1007/s00234-019-02170-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 01/15/2019] [Indexed: 11/29/2022]
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How to Incorporate Dual-Energy Computed Tomography Into Your Neuroradiology Practice: Questions and Answers. J Comput Assist Tomogr 2018; 42:824-830. [PMID: 30371617 DOI: 10.1097/rct.0000000000000810] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Dual-energy computed tomography (DECT) has many current and evolving applications in neuroradiology including material decomposition, improving conspicuity of iodinated contrast enhancement, and artifact reduction. However, there are multiple challenges in incorporating DECT into practice including hardware selection, postprocessing software requirements, technologist and physician training, and numerous workflow issues. This article reviews in a question-and-answer format common issues that arise when incorporating DECT into a busy neuroradiology practice.
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Ohira S, Karino T, Ueda Y, Nitta Y, Kanayama N, Miyazaki M, Koizumi M, Teshima T. How Well Does Dual-energy CT with Fast Kilovoltage Switching Quantify CT Number and Iodine and Calcium Concentrations? Acad Radiol 2018; 25:519-528. [PMID: 29275940 DOI: 10.1016/j.acra.2017.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 10/19/2017] [Accepted: 11/04/2017] [Indexed: 01/13/2023]
Abstract
RATIONALE AND OBJECTIVES Because it is imperative for understanding the performance of dual-energy computed tomography scanner to determine clinical diagnosis, we aimed to assess the accuracy of quantitative measurements using dual-energy computed tomography with fast kilovoltage switching. MATERIALS AND METHODS Quantitative measurements were performed for 16 reference materials (physical density, 0.965-1.550 g/cm3; diameter of rod, 2.0-28.5 mm; iodine concentration, 2-15 mg/mL; and calcium concentration, 50-300 mg/mL) with varying scanning settings, and the measured values were compared to their theoretical values. RESULTS For high-density material, the maximum differences in Hounsfield unit values in the virtual monochromatic images at 50, 70, and 100 keV were -176.2, 61.0, and -35.2 HU, respectively, and the standard deviations over short- and long-term periods were 11.1, 6.1, and 3.5 HU at maximum. The accuracy of the Hounsfield unit measurement at 50 and 70 keV was significantly higher (P < 0.05) with higher radiation output and smaller phantom size. The difference in the iodine and calcium measurements in the large phantom were up to -2.6 and -60.4 mg/mL for iodine (5 mg/mL with 2-mm diameter) and calcium (300 mg/mL) materials, and the difference was improved with a small phantom. Metal artifact reduction software improved subjective image quality; however, the quantitative values were significantly underestimated (P < 0.05) (-49.5, -26.9, and -15.3 HU for 50, 70, and 100 keV, respectively; -1.0 and -17 mg/mL for iodine and calcium concentration, respectively) compared to that acquired without a metal material. CONCLUSIONS The accuracy of quantitative measurements can be affected by material density and the size of the object, radiation output, phantom size, and the presence of metal materials.
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Euler A, Obmann MM, Szucs-Farkas Z, Mileto A, Zaehringer C, Falkowski AL, Winkel DJ, Marin D, Stieltjes B, Krauss B, Schindera ST. Comparison of image quality and radiation dose between split-filter dual-energy images and single-energy images in single-source abdominal CT. Eur Radiol 2018; 28:3405-3412. [DOI: 10.1007/s00330-018-5338-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 01/09/2018] [Accepted: 01/17/2018] [Indexed: 12/25/2022]
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Dual energy computed tomography for the head. Jpn J Radiol 2017; 36:69-80. [DOI: 10.1007/s11604-017-0701-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 10/29/2017] [Indexed: 10/18/2022]
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Pourmorteza A, Symons R, Reich DS, Bagheri M, Cork TE, Kappler S, Ulzheimer S, Bluemke DA. Photon-Counting CT of the Brain: In Vivo Human Results and Image-Quality Assessment. AJNR Am J Neuroradiol 2017; 38:2257-2263. [PMID: 28982793 DOI: 10.3174/ajnr.a5402] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 07/20/2017] [Indexed: 12/28/2022]
Abstract
BACKGROUND AND PURPOSE Photon-counting detectors offer the potential for improved image quality for brain CT but have not yet been evaluated in vivo. The purpose of this study was to compare photon-counting detector CT with conventional energy-integrating detector CT for human brains. MATERIALS AND METHODS Radiation dose-matched energy-integrating detector and photon-counting detector head CT scans were acquired with standardized protocols (tube voltage/current, 120 kV(peak)/370 mAs) in both an anthropomorphic head phantom and 21 human asymptomatic volunteers (mean age, 58.9 ± 8.5 years). Photon-counting detector thresholds were 22 and 52 keV (low-energy bin, 22-52 keV; high-energy bin, 52-120 keV). Image noise, gray matter, and white matter signal-to-noise ratios and GM-WM contrast and contrast-to-noise ratios were measured. Image quality was scored by 2 neuroradiologists blinded to the CT detector type. Reproducibility was assessed with the intraclass correlation coefficient. Energy-integrating detector and photon-counting detector CT images were compared using a paired t test and the Wilcoxon signed rank test. RESULTS Photon-counting detector CT images received higher reader scores for GM-WM differentiation with lower image noise (all P < .001). Intrareader and interreader reproducibility was excellent (intraclass correlation coefficient, ≥0.86 and 0.79, respectively). Quantitative analysis showed 12.8%-20.6% less image noise for photon-counting detector CT. The SNR of photon-counting detector CT was 19.0%-20.0% higher than of energy-integrating detector CT for GM and WM. The contrast-to-noise ratio of photon-counting detector CT was 15.7% higher for GM-WM contrast and 33.3% higher for GM-WM contrast-to-noise ratio. CONCLUSIONS Photon-counting detector brain CT scans demonstrated greater gray-white matter contrast compared with conventional CT. This was due to both higher soft-tissue contrast and lower image noise for photon-counting CT.
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Affiliation(s)
- A Pourmorteza
- From the Department of Radiology and Imaging Sciences (A.P., R.S., D.S.R., M.B., T.E.C., D.A.B.), National Institutes of Health Clinical Center, Bethesda, Maryland.,Department of Radiology and Imaging Sciences (A.P.), Emory University School of Medicine, Atlanta, Georgia
| | - R Symons
- From the Department of Radiology and Imaging Sciences (A.P., R.S., D.S.R., M.B., T.E.C., D.A.B.), National Institutes of Health Clinical Center, Bethesda, Maryland.,Department of Imaging and Pathology (R.S.), Medical Imaging Research Centre, University Hospitals, Leuven, Belgium
| | - D S Reich
- From the Department of Radiology and Imaging Sciences (A.P., R.S., D.S.R., M.B., T.E.C., D.A.B.), National Institutes of Health Clinical Center, Bethesda, Maryland.,Translational Neuroradiology Section (D.S.R.), National Institute of Neurological Disorders and Stroke, Bethesda, Maryland
| | - M Bagheri
- From the Department of Radiology and Imaging Sciences (A.P., R.S., D.S.R., M.B., T.E.C., D.A.B.), National Institutes of Health Clinical Center, Bethesda, Maryland
| | - T E Cork
- From the Department of Radiology and Imaging Sciences (A.P., R.S., D.S.R., M.B., T.E.C., D.A.B.), National Institutes of Health Clinical Center, Bethesda, Maryland.,Departments of Radiological Sciences and Bioengineering (T.E.C.), University of California, Los Angeles, Los Angeles, California
| | - S Kappler
- Siemens (S.K., S.U.), Erlangen, Germany
| | | | - D A Bluemke
- From the Department of Radiology and Imaging Sciences (A.P., R.S., D.S.R., M.B., T.E.C., D.A.B.), National Institutes of Health Clinical Center, Bethesda, Maryland
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Potter CA, Sodickson AD. Dual-Energy CT in Emergency Neuroimaging: Added Value and Novel Applications. Radiographics 2017; 36:2186-2198. [PMID: 27831844 DOI: 10.1148/rg.2016160069] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dual-energy computed tomography (CT) is a powerful diagnostic tool that is becoming more widely clinically available. Dual-energy CT has the potential to aid in the detection or add diagnostic confidence in the evaluation of a variety of emergent neurologic conditions with use of postprocessing techniques that allow one to take advantage of the different x-ray energy-dependent absorption behaviors of different materials. Differentiating iodine from hemorrhage may help in delineating CT angiographic spot signs, which are small foci of intracranial hemorrhage seen on CT angiograms in cases of acute hemorrhage. Bone subtraction can be used to effectively exclude osseous structures surrounding enhancing vessels at imaging for improved vessel visualization and to create images that are similar in appearance to three-dimensional magnetic resonance imaging vessel reconstructions. Bone subtraction may also be helpful for improving the conspicuity of small extra-axial fluid collections and extra-axial masses. Material characterization can be helpful for clarifying whether small foci of intermediate attenuation represent hemorrhage, calcification, or a foreign material, and it may also be useful for quantifying the amount of hemorrhage or iodine in preexisting or incidentally detected lesions. Virtual monochromatic imaging also can be used to problem solve in challenging cases. ©RSNA, 2016.
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Affiliation(s)
- Christopher A Potter
- From the Department of Radiology, Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115
| | - Aaron D Sodickson
- From the Department of Radiology, Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115
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Dual-Energy Computed Tomographic Applications for Differentiation of Intracranial Hemorrhage, Calcium, and Iodine. Neuroimaging Clin N Am 2017; 27:401-409. [DOI: 10.1016/j.nic.2017.03.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Miscellaneous and Emerging Applications of Dual-Energy Computed Tomography for the Evaluation of Intracranial Pathology. Neuroimaging Clin N Am 2017; 27:411-427. [DOI: 10.1016/j.nic.2017.03.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Pérez-Lara A, Forghani R. Dual-Energy Computed Tomography of the Neck. Neuroimaging Clin N Am 2017; 27:499-522. [DOI: 10.1016/j.nic.2017.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Kamalian S, Lev MH, Pomerantz SR. Dual-Energy Computed Tomography Angiography of the Head and Neck and Related Applications. Neuroimaging Clin N Am 2017; 27:429-443. [DOI: 10.1016/j.nic.2017.04.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Detecting Intracranial Hemorrhage Using Automatic Tube Current Modulation With Advanced Modeled Iterative Reconstruction in Unenhanced Head Single- and Dual-Energy Dual-Source CT. AJR Am J Roentgenol 2017; 208:1089-1096. [DOI: 10.2214/ajr.16.17171] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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