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Yap LPP, Sani FM, Chung E, Gowdh NFM, Ng WL, Wong JHD. Customised weight-based volume contrast media protocol for multiphase abdominal computed tomography. Singapore Med J 2024:00077293-990000000-00085. [PMID: 38305361 DOI: 10.4103/singaporemedj.smj-2021-461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 10/19/2022] [Indexed: 02/03/2024]
Abstract
INTRODUCTION Multiphase computed tomography (CT) using fixed volume contrast media may lead to high radiation exposure and toxicity in patients with low body weight. We evaluated a customised weight-based protocol for multiphase CT in terms of radiation exposure, image quality and cost savings. METHODS A total of 224 patients were recruited. An optimised CT protocol was applied using 100 kV and 1 mL/kg of contrast media dosing. The image quality and radiation dose exposure of this CT protocol were compared to those of a standard 120 kV, 80 mL fixed volume protocol. The radiation dose information and CT Hounsfield units were recorded. The signal-to-noise ratio, contrast-to-noise ratio (CNR) and figure of merit (FOM) were used as comparison metrics. The images were assessed for contrast opacification and visual quality by two radiologists. The renal function, contrast media volume and cost were also evaluated. RESULTS The median effective dose was lowered by 16% in the optimised protocol, while the arterial phase images achieved significantly higher CNR and FOM. The radiologists' evaluation showed more than 97% absolute agreement with no significant differences in image quality. No significant differences were found in the pre- and post-CT estimated glomerular filtration rate. However, contrast media usage was significantly reduced by 1,680 mL, with an overall cost savings of USD 421 in the optimised protocol. CONCLUSION The optimised weight-based protocol is cost-efficient and lowers radiation dose while maintaining overall contrast enhancement and image quality.
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Affiliation(s)
- Lilian Poh Poh Yap
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Fadhli Mohamed Sani
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Eric Chung
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Nadia Fareeda Muhammad Gowdh
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Wei Lin Ng
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
| | - Jeannie Hsiu Ding Wong
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Imaging, Universiti Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia
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Otgonbaatar C, Ryu JK, Shin J, Woo JY, Seo JW, Shim H, Hwang DH. Improvement in Image Quality and Visibility of Coronary Arteries, Stents, and Valve Structures on CT Angiography by Deep Learning Reconstruction. Korean J Radiol 2022; 23:1044-1054. [PMID: 36196766 PMCID: PMC9614292 DOI: 10.3348/kjr.2022.0127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE This study aimed to investigate whether a deep learning reconstruction (DLR) method improves the image quality, stent evaluation, and visibility of the valve apparatus in coronary computed tomography angiography (CCTA) when compared with filtered back projection (FBP) and hybrid iterative reconstruction (IR) methods. MATERIALS AND METHODS CCTA images of 51 patients (mean age ± standard deviation [SD], 63.9 ± 9.8 years, 36 male) who underwent examination at a single institution were reconstructed using DLR, FBP, and hybrid IR methods and reviewed. CT attenuation, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and stent evaluation, including 10%-90% edge rise slope (ERS) and 10%-90% edge rise distance (ERD), were measured. Quantitative data are summarized as the mean ± SD. The subjective visual scores (1 for worst -5 for best) of the images were obtained for the following: overall image quality, image noise, and appearance of stent, vessel, and aortic and tricuspid valve apparatus (annulus, leaflets, papillary muscles, and chordae tendineae). These parameters were compared between the DLR, FBP, and hybrid IR methods. RESULTS DLR provided higher Hounsfield unit (HU) values in the aorta and similar attenuation in the fat and muscle compared with FBP and hybrid IR. The image noise in HU was significantly lower in DLR (12.6 ± 2.2) than in hybrid IR (24.2 ± 3.0) and FBP (54.2 ± 9.5) (p < 0.001). The SNR and CNR were significantly higher in the DLR group than in the FBP and hybrid IR groups (p < 0.001). In the coronary stent, the mean value of ERS was significantly higher in DLR (1260.4 ± 242.5 HU/mm) than that of FBP (801.9 ± 170.7 HU/mm) and hybrid IR (641.9 ± 112.0 HU/mm). The mean value of ERD was measured as 0.8 ± 0.1 mm for DLR while it was 1.1 ± 0.2 mm for FBP and 1.1 ± 0.2 mm for hybrid IR. The subjective visual scores were higher in the DLR than in the images reconstructed with FBP and hybrid IR. CONCLUSION DLR reconstruction provided better images than FBP and hybrid IR reconstruction.
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Affiliation(s)
| | - Jae-Kyun Ryu
- Medical Imaging AI Research Center, Canon Medical Systems Korea, Seoul, Korea
| | - Jaemin Shin
- Department of Radiology, Inje University Seoul Paik Hospital, Seoul, Korea
| | - Ji Young Woo
- Department of Radiology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Jung Wook Seo
- Department of Radiology, Inje University Ilsan Paik Hospital, Goyang, Korea
| | - Hackjoon Shim
- Medical Imaging AI Research Center, Canon Medical Systems Korea, Seoul, Korea.,ConnectAI Research Center, Yonsei University College of Medicine, Seoul, Korea
| | - Dae Hyun Hwang
- Department of Radiology, Inje University Seoul Paik Hospital, Seoul, Korea.,Department of Radiology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
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Shen J, Tse JR, Chan F, Fleischmann D. CT Angiography of Venoarterial Extracorporeal Membrane Oxygenation. Radiographics 2021; 42:23-37. [PMID: 34890275 DOI: 10.1148/rg.210079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Imaging plays a central role in the workup of thromboembolic events and bleeding complications in patients treated with venoarterial extracorporeal membrane oxygenation (ECMO) (VA-ECMO), and radiologists should be familiar with the expected hemodynamic changes and flow-related artifacts associated with the VA-ECMO system. VA-ECMO is a form of temporary mechanical circulatory support for critically ill patients with acute, refractory cardiac or cardiopulmonary failure. As the use of VA-ECMO continues to increase, it is important to be aware of associated hemodynamic changes and challenges at imaging. Patients treated with VA-ECMO are at high risk for thromboembolic events and bleeding complications and, thus, often require evaluation with CT angiography (CTA). VA-ECMO can be implemented by using central or peripheral cannulation. The peripheral femorofemoral VA-ECMO circuit in particular alters the sequence and direction of contrast medium enhancement substantially, resulting in flow-related artifacts that can mimic or obscure disease at CTA. Nonopacification can be mistaken for spurious thrombus or simulate complete vascular occlusion, while mixing artifacts can mimic dissections. Misinterpretation of flow-related CTA artifacts can lead to inappropriate surgical or medical intervention. A methodical and multiphasic approach should be taken to CTA imaging strategies and interpretation for patients treated with VA-ECMO. There is no universal CTA protocol for patients on VA-ECMO. Each protocol must be designed for the study indication, with consideration of the configuration of the ECMO cannulas, contrast material injection site, region of interest, native cardiac output, and ECMO flow rate. The authors provide examples of common and unusual VA-ECMO-related artifacts, with a focus on strategies for optimizing CTA image acquisition. Online supplemental material is available for this article. ©RSNA, 2021.
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Affiliation(s)
- Jody Shen
- From the Department of Radiology, Stanford University School of Medicine, 453 Quarry Rd, Mail Code 5659, Palo Alto, CA 94304
| | - Justin Ruey Tse
- From the Department of Radiology, Stanford University School of Medicine, 453 Quarry Rd, Mail Code 5659, Palo Alto, CA 94304
| | - Frandics Chan
- From the Department of Radiology, Stanford University School of Medicine, 453 Quarry Rd, Mail Code 5659, Palo Alto, CA 94304
| | - Dominik Fleischmann
- From the Department of Radiology, Stanford University School of Medicine, 453 Quarry Rd, Mail Code 5659, Palo Alto, CA 94304
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Suchá D, Kino A, Bogart K, Molvin L, Cheng X, Fearon W, Fischbein M, Fleischmann D. Effect of low contrast medium-dose CTA on device sizing and access vessel assessment for TAVR. Eur J Radiol 2020; 124:108826. [DOI: 10.1016/j.ejrad.2020.108826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/09/2019] [Accepted: 01/06/2020] [Indexed: 01/22/2023]
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Laukamp KR, Zopfs D, Wagner A, Lennartz S, Pennig L, Borggrefe J, Ramaiya N, Große Hokamp N. CT artifacts from port systems: Virtual monoenergetic reconstructions from spectral-detector CT reduce artifacts and improve depiction of surrounding tissue. Eur J Radiol 2019; 121:108733. [PMID: 31739270 DOI: 10.1016/j.ejrad.2019.108733] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 10/19/2019] [Accepted: 10/27/2019] [Indexed: 11/27/2022]
Abstract
PURPOSE CT artifacts from port-systems are a common problem in staging- and restaging-examinations and reduce image quality and diagnostic assessment. The purpose of this study was to investigate the reduction of these artifacts using virtual monoenergetic images (VMI) from dual-energy spectral-detector CT (SDCT) in comparison to conventional CT-images (CI). METHOD 50 SDCT-datasets of patients with artifacts from port-chamber and port-catheters were included in this IRB-approved, retrospective study. CI and VMI (range, 40-200 keV, 10 keV increment) were reconstructed from the same acquisition. The quantitative image analysis was performed ROI-based assessing mean and standard deviation of attenuation (HU) in most pronounced hypo- and hyperdense artifacts surrounding to the port-chamber and the distal end of the port-catheter in the superior vena cava. Subjectively, artifact reduction and diagnostic assessment of surrounding soft tissue were rated on 5-point Likert-scales. RESULTS In comparison to CI, VMI of higher keV-values showed strong reduction of hypo- and hyperattenuating artifacts around the port-chamber and port-catheter (CI/VMI200keV: hypodense -104.7 ± 124.7HU/10.8 ± 58.1HU and -101.6 ± 101.5HU/-36.7 ± 32.9HU; hyperdense 240.8 ± 151.6HU/79.6 ± 81.3HU and 108.6 ± 129.3HU/25.9 ± 31.9HU; all p < 0.001). Image noise could also be reduced significantly. The subjective analysis showed significantly reduced artifacts around the port-chamber and port-catheter (CI/VMI200keV: hypodense 3(1-4)/5(4-5) and 3(2-4)/5(4-5); hyperdense 3(1-4)/5(4-5) and 3(2-3)/5(3-5); all p < 0.001) and improved diagnostic assessment of pectoral/subclavian soft tissue for VMI of ≥100keV. Ratings for diagnostic assessment were best between 140-200 keV. Overall interrater agreement was high (ICC = 0.79). CONCLUSIONS Higher keV VMI enabled a significant reduction of artifacts from port-systems around the chamber and the catheter leading to improved assessment of surrounding soft tissue.
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Affiliation(s)
- Kai Roman Laukamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany; Department of Radiology, University Hospitals Cleveland Medical Center, 11000 Euclid Ave, 44106 Cleveland, OH, USA; Department of Radiology, Case Western Reserve University, 10900 Euclid Ave, 44106, Cleveland, OH, USA.
| | - David Zopfs
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Anton Wagner
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Lenhard Pennig
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Jan Borggrefe
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Nikhil Ramaiya
- Department of Radiology, University Hospitals Cleveland Medical Center, 11000 Euclid Ave, 44106 Cleveland, OH, USA; Department of Radiology, Case Western Reserve University, 10900 Euclid Ave, 44106, Cleveland, OH, USA
| | - Nils Große Hokamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany; Department of Radiology, University Hospitals Cleveland Medical Center, 11000 Euclid Ave, 44106 Cleveland, OH, USA; Department of Radiology, Case Western Reserve University, 10900 Euclid Ave, 44106, Cleveland, OH, USA
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Yu Y, Yin W, Liao K, Liu T, Wang X, Sun K, Lu B. Individualized contrast agents injection protocol tailored to body surface area in coronary computed tomography angiography. Acta Radiol 2019; 60:1430-1437. [PMID: 31081338 DOI: 10.1177/0284185119840769] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Yitong Yu
- Department of Radiologic Imaging, Fuwai Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
- State Key Laboratory and National Center for Cardiovascular Diseases, Beijing, People’s Republic of China
| | - Weihua Yin
- Department of Radiologic Imaging, Fuwai Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
- State Key Laboratory and National Center for Cardiovascular Diseases, Beijing, People’s Republic of China
| | - Kai Liao
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, People’s Republic of China
| | - Ting Liu
- Department of Radiology, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning, People’s Republic of China
| | - Ximing Wang
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, People’s Republic of China
| | - Kai Sun
- Department of Radiology, Baotou Central Hospital, Inner Mongolia, People’s Republic of China
| | - Bin Lu
- Department of Radiologic Imaging, Fuwai Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
- State Key Laboratory and National Center for Cardiovascular Diseases, Beijing, People’s Republic of China
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The Usefulness of Fenestrated Intravenous Catheters Compared With Nonfenestrated Catheter for Cardiac Multidetector Computed Tomography. J Comput Assist Tomogr 2019; 43:423-427. [PMID: 31082947 DOI: 10.1097/rct.0000000000000855] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE To compare the fenestrated intravenous (IV) catheter and nonfenestrated conventional IV catheter in terms of contrast enhancement and injection pressure for coronary computed tomography angiography. METHODS Three hundred patients were prospectively and consecutively enrolled to either the 20-gauge nonfenestrated conventional (group 1) IV catheter group or the 20-gauge fenestrated (group 2) or 22-gauge fenestrated (group 3) IV catheter groups. We analyzed mean vascular attenuations in the ascending aorta, left main coronary artery, left ventricular (LV) cavity, and descending aorta. Injection pressure using pound-force per square inch (PSI) and extravasation of contrast media were recorded. RESULTS Mean attenuations of the left main coronary artery, LV cavity, and descending aorta were significantly higher in group 2 than in group 1 (P ≤ 0.001, P ≤ 0.001, P ≤ 0.001, respectively). Moreover, injection pressure was significantly lower in group 2 than in group 1 (208.3 vs 216.9 PSI, P = 0.006). Mean vascular attenuations of the left main coronary artery, LV cavity, and descending aorta were significantly higher in group 3 than in group 1 (P = 0.016, P = 0.029, P = 0.001, respectively). However, injection pressure was not statistically significant between group 3 and group 1 (213.6 vs 216.9 PSI, P = 0.355). No extravasation occurred in any patient groups during the study. CONCLUSIONS We suggest that fenestrated IV catheter is useful in terms of higher vascular attenuation and lower injection pressure for coronary computed tomography angiography. It has a potential merit in patients with fragile and small veins.
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Virtual Monoenergetic Images for Diagnostic Assessment of Hypodense Lesions Within the Liver: Semiautomatic Estimation of Window Settings Using Linear Models. J Comput Assist Tomogr 2018; 42:925-931. [PMID: 30371610 DOI: 10.1097/rct.0000000000000794] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE The aim of the study was to establish the reference window settings for display of virtual monoenergetic images (VMIs) from spectral detector computed tomography when assessing hypodense liver lesions. METHODS In patients with cysts (n = 24) or metastases (n = 26), objective (HU, signal-to-noise ratio [SNR]) and subjective (overall image quality, lesion conspicuity and noise) were assessed. Furthermore, 2 readers determined optimal window center/width (C/W) for conventional images (CIs) and VMIs of 40 to 120 keV. Center/width were modeled against HUliv with and without respect to the keV level (models A and B). RESULTS Attenuation and SNR were significantly higher in low-keV VMIs and improved overall image quality and lesion conspicuity (P ≤ 0.05). Model B provided valid estimations of C/W, whereas model A was slightly less accurate. CONCLUSIONS The increase in attenuation and SNR on low-keV VMIs requires adjustment of C/W, and they can be estimated in dependency of HUliv using linear models. Reference values for standard display of VMIs of 40 to 120 keV are reported.
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Contrast media injection protocol optimization for dual-energy coronary CT angiography: results from a circulation phantom. Eur Radiol 2018; 28:3473-3481. [PMID: 29488083 DOI: 10.1007/s00330-018-5308-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 12/20/2017] [Accepted: 01/03/2018] [Indexed: 12/12/2022]
Abstract
OBJECTIVES To investigate the minimum iodine delivery rate (IDR) required to achieve diagnostic coronary attenuation (300 HU) with dual-energy coronary CTA. METHODS Acquisitions were performed on a circulation phantom with a third- generation dual-source CT scanner. Contrast media was injected for a fixed time whilst IDRs varied from 1.0 to 0.3 gI/s in 0.1-gI/s intervals. Noise-optimized virtual monoenergetic imaging (VMI+) reconstructions from 40 to 90 keV in 5 keV increments were generated. Contrast-to-noise ratio (CNR) and coronary HU were measured for each injection. RESULTS VMI+ from 40-70 keV reached diagnostic attenuation with at least one IDR. The minimum IDR achieving a diagnostic attenuation ranged from 0.4 gI/s at 40 keV (312.8 HU) to 1.0 gI/s at 70 keV (334.1 HU). Attenuation values reached with IDR of 1.0 gI/s were significantly higher at each keV level (p<0.001). CNR showed a near perfect correlation with the IDR (ρ≥0.962; p<0.001), the IDR of 1.0 gI/s provided the highest CNR at each keV level, achieving the highest overall value at 40 keV (54.0±3.1). CONCLUSIONS IDRs from 0.4-1.0 gI/s associated with VMI+ from 40-70 keV provide diagnostic coronary attenuation with dual-energy coronary CTA. KEY POINTS • Iodine delivery rate (IDR) is a major determinant of contrast enhancement. • Low-keV noise-optimized monoenergetic images (VMI+) maximize iodine attenuation. • Low-keV VMI+ allows for lower IDRs while maintaining adequate coronary attenuation. • Lowest IDR to reach 300 HU was 0.4 gI/s, 40 keV VMI+.
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Hwang JY, Choo KS, Choi YY, Kim JH, Ryu H, Han J, Kim YW, Jeon UB, Nam KJ. Subjective and objective image differences in pediatric computed tomography cardiac angiography using lower iodine concentration. Pediatr Radiol 2017; 47:701-709. [PMID: 28236133 DOI: 10.1007/s00247-017-3795-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/22/2017] [Accepted: 02/02/2017] [Indexed: 10/20/2022]
Abstract
BACKGROUND Several recent studies showed the optimal contrast enhancement with a low-concentration and iso-osmolar contrast media in both adult and pediatric patients. However, low contrast media concentrations are not routinely used due to concerns of suboptimal enhancement of cardiac structures and small vessels. OBJECTIVE To evaluate the feasibility of using iso-osmolar contrast media containing a low iodine dose for CT cardiac angiography at 80 kilovolts (kVp) in neonates and infants. MATERIALS AND METHODS The iodixanol 270 group consisted of 79 CT scans and the iopromide 370 group of 62 CT scans in patients ≤1 year old. Objective measurement of the contrast enhancement was analyzed and contrast-to-noise ratios of the ascending aorta and left ventricle were calculated. Regarding subjective measurement, a four-point scale system was devised to evaluate degrees of contrast enhancement, image noise, motion artifact and overall image quality of each image set. Reader performance for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment was evaluated. RESULTS Group objective and subjective measurements were nonsignificantly different. Overall sensitivity, specificity and diagnostic accuracy for correctly differentiating iodixanol 270 and iopromide 370 by visual assessment were 42.8%, 59%, and 50%, respectively. CONCLUSION The application of iodixanol 270 achieved optimal enhancement for performing pediatric cardiac CT angiography at 80 kVp in neonates and infants. Objective measurements of contrast enhancement and subjective image quality assessments were not statistically different in the iodixanol 270 and iopromide 370 groups.
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Affiliation(s)
- Jae-Yeon Hwang
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea.,Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Geumo-ro 20, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - Ki Seok Choo
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea.
| | - Yoon Young Choi
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - Jin Hyeok Kim
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - Hwaseong Ryu
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - Junhee Han
- Division of Biostatistics, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Geumo-ro 20, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - Yong-Woo Kim
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - Ung Bae Jeon
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - Kyung Jin Nam
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
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Optimizing Contrast Media Injection Protocols in Computed Tomography Angiography at Different Tube Voltages. J Comput Assist Tomogr 2017; 41:804-810. [DOI: 10.1097/rct.0000000000000613] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Du X, Yang X, Cheng W, Huang N, Zhou L, Zhang J. Spectral CT imaging in cervical computed tomography angiography: comparison of spectral CT monochromatic imaging and conventional CT polychromatic imaging. Int J Clin Pract 2016; 70 Suppl 9B:B44-9. [PMID: 27577513 DOI: 10.1111/ijcp.12854] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 06/15/2016] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE To compare the image quality of spectral CT monochromatic imaging and conventional CT polychromatic imaging for analysing CTAs in patients with cervical cancer. METHODS In this IRB approved prospective study, 60 patients who had been diagnosed with cervical cancer underwent pelvic arterial CTA between May 2013 and July 2013. They were randomly divided into two groups; one group (30 patients) received 120 kVp polychromatic imaging (conventional CT group) and the other group (30 patients) received spectral CT imaging (spectral CT group), while all patients in both the groups received injections of 1 ml/kg of contrast agent. A total of 101 sets of monochromatic images (40-140 keV) were obtained via data reconstruction in the spectral CT group, and the monochromatic images with the best contrast-to-noise ratio (CNR) between the common iliac artery and pelvic fat (i.e. the best monochromatic energy) were selected. The best monochromatic images for the spectral CT group and the polychromatic images for the conventional CT group were postprocessed and visualised in MIP, VR and CPR mode. The CT attenuation value, noise and CNR of bilateral common iliac arteries were measured with the best monochromatic energy, as well as with 70 keV, in the spectral CT group and in the conventional CT group. The quality of the CT images was evaluated with a 5-point scale. The CTDIvol and the dose-length product (DLP) of the two groups were measured, and the results were statistically analysed. RESULTS When images were at 50±1 keV, the common iliac artery and pelvic fat had the highest CNR, which was 72.00% higher than the images at 70 keV (P=.001) in the spectral group, and thus, the images at 50±1 keV were considered to have the best monochromatic energy. The average CT value of the internal iliac artery, which had the best monochromatic energy from the spectral CT group, was higher than that of the images from the conventional CT group (603.96±62.68 vs 251.24±28.77; P<.001), and the differences in the CNR (73.97±11.83 vs 45.21±16.63) and the subjective score (3.10±1.73 vs 2.80±1.63) were statistically significant (both P<.05). There were no significant differences in the CTDIvol (10.48±2.86 vs 12.38±1.88 mGy) or the DLP (317.76±95.50 vs 332.25±21.25 mGy cm) between the spectral and the conventional CT groups. CONCLUSION Monochromatic spectral CT imaging has excellent soft tissue contrast and good spatial resolution and can visualise the arteries and branches supplying the tumours more clearly in patients with cervical cancer. Compared with polychromatic images, monochromatic spectral CT images are higher quality, which helps the treatment of patients with cervical cancer.
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Affiliation(s)
- Xiaosong Du
- MR & CT Room, Shanxi Cancer Hospital, Taiyuan, Shanxi, China
| | - Xiaotang Yang
- MR & CT Room, Shanxi Cancer Hospital, Taiyuan, Shanxi, China
| | - Weiling Cheng
- MR & CT Room, Shanxi Cancer Hospital, Taiyuan, Shanxi, China
| | | | - Lifang Zhou
- MR & CT Room, Shanxi Cancer Hospital, Taiyuan, Shanxi, China
| | - Jianxin Zhang
- MR & CT Room, Shanxi Cancer Hospital, Taiyuan, Shanxi, China
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Bui TD, Gelfand D, Whipple S, Wilson SE, Fujitani RM, Conroy R, Pham H, Gordon IL. Comparison of CT and Catheter Arteriography for Evaluation of Peripheral Arterial Disease. Vasc Endovascular Surg 2016; 39:481-90. [PMID: 16382269 DOI: 10.1177/153857440503900604] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Computed tomographic arteriography (CTA) has emerged as a promising technique for less invasive imaging of the lower extremity arteries. The aim of this study was to determine the concordance between CTA and catheter arteriography (CA) in patients with peripheral arterial disease (PAD). Twenty-five patients underwent both CTA and CA, and each set of images was interpreted independently by 3 readers. The infrarenal arteries were divided into 16 segments, and each segment was scored as: 1 = stenosis <50%; 2 = 50–99% stenosis; 3 = occlusion. Modal scores from 3 readers were used to compare results for each segment, with CA assumed to represent true arterial anatomy. Agreement between CTA and CA readings was defined as: concordance (modal scores were identical); moderate discrepancy (MD) (modal scores differed by 1); or severe discrepancy (SD) (modal scores differed by 2). In total, 718 segments were assessed by both CTA and CA. For all segments, the sensitivity and specificity of CTA for <50% stenosis was 86% and 90%; for 50–99% stenosis, sensitivity and specificity were 79% and 89%; and for occlusion, 85% and 98%. Above-knee (AK) CTA scores had slightly better concordance of 86.1% than below-knee (BK) readings (82.3%) (p = 0.104). Severe discrepancies between AK CTA and CA scores were observed in 1.8% of segments compared to 5.4% of BK segments (p = 0.038). Poor CTA image quality was the cause in 20% of AK segments and 28% of BK segments. Poor CA image quality was the cause in 8% of AK and 7% of BK discrepancies. Registration disagreement (stenosis observed in a level in 1 study attributed to a different level in the other) accounted for 18% of AK and 17% of BK discrepancies. In 54% of AK and 48% of BK discrepancies, neither image quality nor registration errors were identified, indicating that inherent differences in the depiction of stenosis by CA and CTA were responsible. When discrepancies caused by registration error were excluded, SD observed in BK segments (4.0%) remained significantly higher than in AK segments (1.25%) (p = 0.029), and poor CTA quality image was the most common cause (76%) of severe BK discrepancies. In AK discrepancies without an identifiable technical cause, CTA uniformly showed more stenosis, suggesting greater CTA diagnostic precision in larger vessels. In general, agreement between CTA and CA was moderately good. Compared to CA, CTA may be better at depicting stenosis in large, proximal vessels owing to the superior accuracy of cross-sectional images in the measurement of stenosis. There appeared to be poorer CT resolution and higher frequency of severe discrepancies between CTA and CA in BK arteries.
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Affiliation(s)
- Trung D Bui
- VA Long Beach Healthcare System, Department of Vascular Surgery, Long Beach, CA and UCI Medical Center, Department of Vascular and Endovascular Surgery, Orange, CA 92868, USA.
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Quantification of coronary flow using dynamic angiography with 320-detector row CT and motion coherence image processing: Detection of ischemia for intermediate coronary stenosis. Eur J Radiol 2016; 85:996-1003. [DOI: 10.1016/j.ejrad.2016.02.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 01/27/2016] [Accepted: 02/27/2016] [Indexed: 01/05/2023]
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Jo BG, Song YG, Shim SG, Kim YW. Comparison of enhancement and image quality: different iodine concentrations for liver on 128-slice multidetector computed tomography in the same chronic liver disease patients. Korean J Intern Med 2016; 31:461-9. [PMID: 26701234 PMCID: PMC4855087 DOI: 10.3904/kjim.2014.210] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 11/25/2014] [Accepted: 12/22/2014] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND/AIMS The objective of this study was to compare the degree of hepatic enhancement and image quality using contrast media of different iodine concentrations with the same iodine dose. METHODS From July 2011 to June 2013, 50 patients with chronic liver disease who underwent baseline and follow-up 128-slice multidetector computed tomography(MDCT) using contrast media with 350 mg I/mL (group A) and 400 mg I/mL (group B) iodine concentrations were included in this prospective study. The patients were randomly allocated to one of two protocols: 350 mg I/mL initially and then 400 mg I/mL; and 400 mg I/mL initially and then 350 mg I/mL. The bolus tracking technique was used to initiate the arterial phase scan. The computed tomography values of hepatic parenchyma, abdominal aorta and portal vein were measured. The degrees of hepatic and vascular enhancement were rated on a 4-point scale for qualitative assessment. The paired Student t test was used to compare outcome variables. RESULTS The mean hepatic enhancement was significantly higher in group B than in group A during the portal (p = 0.025) and equilibrium phases (p = 0.021). In all phases, group B had significantly higher mean liver-to-aorta contrast (p < 0.05) and mean visual scores for hepatic and vascular enhancement (p < 0.001). CONCLUSIONS This study showed that a higher iodine concentration (400 mg I/mL) in contrast media was more effective at improving hepatic enhancement in portal and equilibrium phase images and overall image quality using 128-slice MDCT in chronic liver disease patients.
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Affiliation(s)
- Byoung Goo Jo
- Department of Radiology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
| | - Yun Gyu Song
- Department of Radiology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
- Correspondence to Yun Gyu Song, M.D. Department of Radiology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, 158 Paryong-ro, Masanhoewon-gu, Changwon 51353, Korea Tel: +82-55-290-6092 Fax: +82-55-290-6087 E-mail:
| | - Sang Goon Shim
- Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
| | - Young Wook Kim
- Department of Occupational and Environmental Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
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Park EA, Lee W, Kang DK, Kim SJ, Kim YJ, Kim Y, Sung YM, Song SY, Oh YW, Yong HS, Lee H, Jeon EY, Jin GY, Choi BW, Choi SI. Comparison of Iohexol-380 and Iohexol-350 for Coronary CT Angiography: A Multicenter, Randomized, Double-Blind Phase 3 Trial. Korean J Radiol 2016; 17:330-8. [PMID: 27134522 PMCID: PMC4842853 DOI: 10.3348/kjr.2016.17.3.330] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 02/13/2016] [Indexed: 11/24/2022] Open
Abstract
Objective This multi-center, randomized, double-blind, phase 3 trial was conducted to compare the safety and efficacy of contrast agents iohexol-380 and iohexol-350 for coronary CT angiography in healthy subjects. Materials and Methods Volunteers were randomized to receive 420 mgI/kg of either iohexol-350 or iohexol-380 using a flow rate of 4 mL/sec. All adverse events were recorded. Two blinded readers independently reviewed the CT images and conflicting results were resolved by a third reader. Luminal attenuations (ascending aorta, left main coronary artery, and left ventricle) in Hounsfield units (HUs) and image quality on a 4-point scale were calculated. Results A total of 225 subjects were given contrast media (115 with iohexol-380 and 110 with iohexol-350). There was no difference in number of adverse drug reactions between groups: 75 events in 56 (48.7%) of 115 subjects in the iohexol-380 group vs. 74 events in 51 (46.4%) of 110 subjects in the iohexol-350 group (p = 0.690). No severe adverse drug reactions were recorded. Neither group showed an increase in serum creatinine. Significant differences in mean density between the groups was found in the ascending aorta: 375.8 ± 71.4 HU with iohexol-380 vs. 356.3 ± 61.5 HU with iohexol-350 (p = 0.030). No significant differences in image quality scores between both groups were observed for all three anatomic evaluations (all, p > 0.05). Conclusion Iohexol-380 provides improved enhancement of the ascending aorta and similar attenuation of the coronary arteries without any increase in adverse drug reactions, as compared with iohexol-350 using an identical amount of total iodine.
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Affiliation(s)
- Eun-Ah Park
- Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea
| | - Whal Lee
- Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea
| | - Doo Kyoung Kang
- Department of Radiology, Ajou University School of Medicine, Suwon 16499, Korea
| | - Sung Jin Kim
- Department of Radiology, Chungbuk National University Hospital, Cheongju 28644, Korea
| | - Young-Ju Kim
- Department of Radiology, Yonsei University Wonju College of Medicine, Wonju Severance Christian Hospital, Wonju 26426, Korea
| | - Yookyung Kim
- Department of Radiology, Ewha Womans University Mokdong Hospital, Seoul 07985, Korea
| | - Yon Mi Sung
- Department of Radiology, Gachon University Gil Medical Center, Incheon 21565, Korea
| | - Soon-Young Song
- Department of Radiology, Hanyang University Seoul Hospital, Seoul 04763, Korea
| | - Yu-Whan Oh
- Department of Radiology, Korea University Anam Hospital, Seoul 02841, Korea
| | - Hwan Seok Yong
- Department of Radiology, Korea University Guro Hospital, Seoul 08308, Korea
| | - Heon Lee
- Department of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon 14584, Korea
| | - Eui-Yong Jeon
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang 14068, Korea
| | - Gong-Yong Jin
- Department of Radiology, Chonbuk National University Medical School and Hospital, Institute of Medical Science, Research Institute of Clinical Medicine and Biomedical Research Institute, Jeonju 54907, Korea
| | - Byoung Wook Choi
- Department of Radiology, Severance Hospital, Yonsei University Health System, Seoul 03722, Korea
| | - Sang-Il Choi
- Department of Radiology, Seoul National University Bundang Hospital, Seongnam 13620, Korea
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Xing Y, Azati G, Pan CX, Dang J, Jha S, Liu WY. Improving Patient to Patient CT Value Uniformity with an Individualized Contrast Medium Protocol Tailored to Body Weight and Contrast Medium Concentration in Coronary CT Angiography. PLoS One 2015; 10:e0132412. [PMID: 26167680 PMCID: PMC4500390 DOI: 10.1371/journal.pone.0132412] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 06/14/2015] [Indexed: 11/19/2022] Open
Abstract
To determine whether body weight and concentration dependent contrast medium (CM) injection protocols can improve patient to patient CT value uniformity more than the conventional injection protocols with fixed injection parameters in coronary CT angiography (CCTA), one hundred and sixty patients who underwent CCTA were prospectively randomized into two groups. Group A (n = 80) used individualized-protocol with adjusted injection rate based on patient weight and contrast medium concentration to obtain constant iodine load of 280 mgI/kg while group B (n = 80) followed the conventional contrast injection protocol with total injection volume of 80ml and constant injection rate of 5.5ml/s. For both groups, patients were further divided into four subgroups with different CM concentrations: A1, B1 (300 mg I/ml); A2, B2 (320 mg I/ml); A3, B3 (350 mg I/ml) and A4 and B4 (370 mg I/ml). For each patient, the CT values of the ascending aorta, left ventricle and coronary arteries were measured. One-way analysis of variance was used to compare CT values among subgroups. Among the subgroups of A, sufficient attenuation of greater than 300HU was obtained in all target vessels with no difference among them. Among the subgroups of B, the CT values had significant difference in left ventricle, left circumflex branch, proximal and distal segment of the right coronary artery (all p < 0.05), and the attenuation with 300 mg I/ml CM concentration was significantly lower than that with 370 mg I/ml. Compared with group B, group A used less volume (62.83 ml vs. 80.00 ml, P<0.001) and lower rate (5.21 ml/s vs. 5.50 ml/s, P<0.001) of CM. Compared with the conventional contrast medium injection protocol with fixed volume and injection rate, the individualized-protocol based on patient weight and contrast concentration provides overall contrast dose reduction and achieves more homogenous attenuation among different coronary vessels and patients.
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Affiliation(s)
- Yan Xing
- Department of Radiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - Gulina Azati
- Department of Radiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - Cun-xue Pan
- Department of Radiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - Jun Dang
- Department of Radiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - Sailendra Jha
- Department of Radiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - Wen-ya Liu
- Department of Radiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
- * E-mail:
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Palacio D, Benveniste MF, Betancourt-Cuellar SL, Gladish GW. Multidetector computed tomography pulmonary angiography pitfalls in the evaluation of pulmonary embolism with emphasis in technique. Semin Roentgenol 2015; 50:217-25. [PMID: 26002242 DOI: 10.1053/j.ro.2015.01.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Diana Palacio
- Department of Medical Imaging, The University of Arizona College of Medicine, Tucson, Arizona USA; Department of Radiology, University of Texas MD Anderson Cancer Center, Houston, TX.
| | - Marcelo F Benveniste
- Department of Radiology, University of Texas MD Anderson Cancer Center, Houston, TX
| | | | - Gregory W Gladish
- Department of Radiology, University of Texas MD Anderson Cancer Center, Houston, TX
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20
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Application of low tube voltage coronary CT angiography with low-dose iodine contrast agent in patients with a BMI of 26–30 kg/m2. Clin Radiol 2015; 70:138-45. [PMID: 25468636 DOI: 10.1016/j.crad.2014.10.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 09/26/2014] [Accepted: 10/08/2014] [Indexed: 10/24/2022]
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Diagnostic efficiency of low-dose CT angiography compared with conventional angiography in peripheral arterial occlusions. AJR Am J Roentgenol 2014; 201:W906-14. [PMID: 24261398 DOI: 10.2214/ajr.12.10209] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to assess the diagnostic efficiency and radiation dose of peripheral arterial CT angiography (CTA) performed at a low tube voltage of 70 kV in comparison with conventional angiography. SUBJECTS AND METHODS Thirty consecutive patients (body mass index ≤ 25 kg/m(2)) with known or suspected peripheral arterial occlusion diseases underwent both CTA at a low tube voltage of 70 kV and conventional angiography. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of peripheral arterial CTA were evaluated. The radiation dose was recorded. RESULTS Diagnostic CTA images were obtained in all patients. CTA allowed accurate identification, characterization, and measurement of all peripheral arterial occlusive diseases. In conventional angiography, 360 diseased segments were found among the 810 segments evaluated. The sensitivity, specificity, PPV, NPV, and accuracy of CTA were 100% (95% CI, 98.81-100%), 93.5% (90.96-95.36%), 90.86% (87.38-93.45%), 100% (99.17-100%), and 96.05% (94.48-97.19%), respectively, with a kappa value of 0.92 (excellent agreement). The mean CT dose index was 3.71 ± 0.8 mGy, and the dose-length product was 446.6 ± 35.7 mGy × cm. The effective dose was 1.94 ± 0.21 mSv for CTA and 4.41 ± 0.64 mSv for conventional angiography. CONCLUSION CTA of peripheral arteries with a low tube voltage of 70 kV provides reliable information and serves as a rapidly performed and easily available "one-stop-shop" imaging modality in the diagnosis of peripheral arterial occlusion diseases.
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Verburg FA, Apitzsch J, Lensing C, Kuhl CK, Pietsch H, Mottaghy FM, Behrendt FF. Body surface area adapted iopromide 300mg/ml versus 370mg/ml contrast medium injection protocol: Influence on quantitative and clinical assessment in combined PET/CT. Eur J Radiol 2013; 82:2348-52. [DOI: 10.1016/j.ejrad.2013.09.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/12/2013] [Accepted: 09/14/2013] [Indexed: 10/26/2022]
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Zheng M, Liu Y, Wei M, Wu Y, Zhao H, Li J. Low concentration contrast medium for dual-source computed tomography coronary angiography by a combination of iterative reconstruction and low-tube-voltage technique: feasibility study. Eur J Radiol 2013; 83:e92-9. [PMID: 24332352 DOI: 10.1016/j.ejrad.2013.11.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 10/16/2013] [Accepted: 11/02/2013] [Indexed: 11/18/2022]
Abstract
OBJECTIVES To assess the impact of low-concentration contrast medium on vascular enhancement, image quality and radiation dose of coronary CT angiography (cCTA) by using a combination of iterative reconstruction (IR) and low-tube-voltage technique. MATERIALS AND METHODS One hundred patients were prospectively randomized to two types of contrast medium and underwent prospective electrocardiogram-triggering cCTA (Definition Flash, Siemens Healthcare; collimation: 128 mm × 0.6mm; tube current: 300 mAs). Fifty patients received Iopromide 370 were scanned using the conventional tube setting (100 kVp or 120 kVp if BMI ≥ 25 kg/m(2)) and reconstructed with filtered back projection (FBP). Fifty patients received Iodixanol 270 were scanned using the low-tube-voltage (80 kVp or 100 kVp if BMI ≥ 25 kg/m(2)) technique and reconstructed with IR. CT attenuation was measured in coronary artery and other anatomical regions. Noise, image quality and radiation dose were compared. RESULTS Compared with two Iopromide 370 subgroups, Iomeprol 270 subgroups showed no significant difference in CT attenuation (576.63 ± 95.50 vs. 569.51 ± 118.93 for BMI< 25 kg/m(2), p=0.647 and 394.19 ± 68.09 vs. 383.72 ± 63.11 for BMI ≥ 25 kg/m(2), p=0.212), noise (in various anatomical regions of interest) and image quality (3.5 vs. 4.0, p=0.13), but significantly (0.41 ± 0.17 vs. 0.94 ± 0.45 for BMI< 25 kg/m(2), p<0.001 and 1.14 ± 0.24 vs. 2.37 ± 0.69 for BMI ≥ 25 kg/m(2), p<0.001) lower radiation dose, which reflects dose saving of 56.4% and 51.9%, respectively. CONCLUSIONS Combined IR with low-tube-voltage technique, a low-concentration contrast medium of 270 mg I/ml can still maintain the contrast enhancement without impairing image quality, as well as significantly lower the radiation dose.
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Affiliation(s)
- Minwen Zheng
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China.
| | - Ying Liu
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China.
| | - Mengqi Wei
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China.
| | - Yongjie Wu
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China.
| | - Hongliang Zhao
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China.
| | - Jian Li
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, 127# West Changle Road, Xi'an 710032, Shaanxi Province, China.
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Xue M, Zhang H, Kligerman S, Klahr P, D’Souza W, Lu W. Individually optimized uniform contrast enhancement in CT angiography for the diagnosis of pulmonary thromboembolic disease-A simulation study. Med Phys 2013; 40:121906. [DOI: 10.1118/1.4829529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Kopp AF, Küttner A, Trabold T, Heuschmid M, Schröder S, Claussen CD. Cardiac and vascular MDCT: thoracic imaging. Eur Radiol 2013; 13 Suppl 5:M73-81. [PMID: 14989614 DOI: 10.1007/s00330-003-2139-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andreas F Kopp
- Department of Diagnostic Radiology, Eberhard Karls University Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany.
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Affiliation(s)
- Sanjay Saini
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, White 270-E, 55 Fruit Street, Boston, MA 02114, USA.
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Identification of the iodine concentration that yields the highest intravascular enhancement in MDCT angiography. AJR Am J Roentgenol 2013; 200:1151-6. [PMID: 23617503 DOI: 10.2214/ajr.12.8984] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The objective of our study was to identify the iodine concentration that yields the highest intravascular contrast enhancement in MDCT angiography by intraindividual comparison in an animal model. MATERIALS AND METHODS Six pigs underwent repeated chest MDCT examinations under standardized conditions using the same contrast medium (iopromide) with different iodine concentrations (150, 240, 300, and 370 mg I/mL). The contrast injection protocol was adapted to ensure an identical iodine delivery rate of 1.5 g I/s and the same total iodine dose of 300 mg/kg of body weight for all studies. Dynamic CT scans were acquired at the levels of the pulmonary artery and the ascending and descending aorta. Pulmonary and aortic peak enhancement values as well as time to peak (TTP) were calculated from time-enhancement curves. RESULTS Pulmonary and aortic peak contrast enhancement values were significantly higher with the 240 and 300 mg I/mL contrast media than the 150 and 370 mg I/mL contrast media (e.g., ascending aorta: 240 vs 150, p = 0.0070; 300 vs 150, p = 0.0096; 240 vs 370, p = 0.0262; 300 vs 370, p = 0.0079). TTP values tended to be lower for the 150 mg I/mL contrast medium than for the contrast media with higher iodine concentrations. CONCLUSION Comparison of contrast media with iodine concentrations ranging from 150 to 370 mg I/mL showed that contrast enhancement was significantly improved with the use of 240 and 300 mg I/mL contrast media given a fixed identical iodine delivery and normalized total iodine load in a porcine model. Contrast media with a moderate iodine concentration are most suitable for obtaining the highest intravascular contrast enhancement in CT angiography.
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Kidoh M, Nakaura T, Nakamura S, Awai K, Utsunomiya D, Namimoto T, Harada K, Yamashita Y. Novel contrast-injection protocol for coronary computed tomographic angiography: contrast-injection protocol customized according to the patient's time-attenuation response. Heart Vessels 2013; 29:149-55. [PMID: 23512260 DOI: 10.1007/s00380-013-0338-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 03/01/2013] [Indexed: 01/03/2023]
Abstract
We developed a new individually customized contrast-injection protocol for coronary computed tomography (CT) angiography based on the time-attenuation response in a test bolus, and investigated its clinical applicability. We scanned 60 patients with suspected coronary diseases using a 64-detector CT scanner, who were randomly assigned to one of two protocols. In protocol 1 (P1), we estimated the contrast dose to yield a peak aortic attenuation of 400 HU based on the time-attenuation response to a small test-bolus injection (0.3 ml/kg body weight) delivered over 9 s. Then we administered a customized contrast dose over 9 s. In protocol 2 (P2), the dose was tailored to the patient's body weight; this group received 0.7 ml/kg body weight with an injection duration of 9 s. We compared the two protocols for dose of contrast medium, peak attenuation, variations in attenuation values of the ascending aorta, and the success rate of adequate attenuation (250-350 HU) of the coronary arteries. The contrast dose was significantly smaller in P1 than in P2 (36.9 ± 9.2 vs 43.1 ± 7.0 ml, P < 0.01). Peak aortic attenuation was significantly less under P1 than under P2 (384.1 ± 25.0 vs 413.5 ± 45.7, P < 0.01). The mean variation (standard deviation) of the attenuation values was smaller in P1 than in P2 (25.0 vs 45.7, P < 0.01). The success rate of adequate attenuation of the coronary arteries was significantly higher with P1 than with P2 (85.0 vs 65.8 %, P < 0.01). P1 facilitated a reduction in the contrast dose, reduced the individual variations in peak aortic attenuation, and achieved optimal coronary CT attenuation (250-350 HU) more frequently than P2.
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Affiliation(s)
- Masafumi Kidoh
- Diagnostic Radiology, Amakusa Medical Center, Kameba 854-1, Amakusa, Kumamoto, 863-0046, Japan,
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Contrast medium injection protocol adjusted for body surface area in combined PET/CT. Eur Radiol 2013; 23:1970-7. [DOI: 10.1007/s00330-013-2781-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 12/21/2012] [Accepted: 01/06/2013] [Indexed: 10/27/2022]
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Kilovoltage dependence of the attenuation of a potassium iodide/water solution on CT: presentation of a computer model implementing polychromatic character of the X-ray photon beam. J Comput Assist Tomogr 2012; 36:602-9. [PMID: 22992613 DOI: 10.1097/rct.0b013e31825eaeac] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To describe a program that simulates a computed tomographic scan with the polychromatic aspect of the output of the x-ray tube implemented. This program can be used in the study of the attenuation of different solutions/solutes. These results can subsequently guide the radiologist to obtain a satisfying contrast enhancement at lower tube voltages and eventually lower contrast volumes. MATERIALS AND METHODS A Matlab program was written to simulate a computed tomographic scan. The spectrum of the x-ray tube at different kilovoltages was generated with another program (XOP) and used as input. Beam-hardening correction and zero padding were added. The results were validated with attenuation measurements of a corresponding potassium iodide solution in water. RESULTS There was a good agreement between the calculated and measured attenuations; the calculated results matched with the measured values and fell within a 5% deviation. CONCLUSION It is possible to simulate correctly the attenuation of a potassium iodide in water solution in silico. This can be helpful to determine kilovoltages, administered contrast medium volumes and concentrations to reduce the irradiation of the patients, and obtain equally good contrast enhancement on a basis other than empirical.
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Millon D, Derelle AL, Omoumi P, Tisserand M, Schmitt E, Foscolo S, Anxionnat R, Bracard S. Nontraumatic subarachnoid hemorrhage management: evaluation with reduced iodine volume at CT angiography. Radiology 2012; 264:203-9. [PMID: 22627598 DOI: 10.1148/radiol.12111384] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate the technical quality and the diagnostic performance of a protocol with use of low volumes of contrast medium (25 mL) at 64-detector spiral computed tomography (CT) in the diagnosis and management of adult, nontraumatic subarachnoid hemorrhage (SAH). MATERIALS AND METHODS This study was performed outside the United States and was approved by the institutional review board. Intracranial CT angiography was performed in 73 consecutive patients with nontraumatic SAH diagnosed at nonenhanced CT. Image quality was evaluated by two observers using two criteria: degree of arterial enhancement and venous contamination. The two independent readers evaluated diagnostic performance (lesion detection and correct therapeutic decision-making process) by using rotational angiographic findings as the standard of reference. Sensitivity, specificity, and positive and negative predictive values were calculated for patients who underwent CT angiography and three-dimensional rotational angiography. The intraclass correlation coefficient was calculated to assess interobserver concordance concerning aneurysm measurements and therapeutic management. RESULTS All aneurysms were detected, either ruptured or unruptured. Arterial opacification was excellent in 62 cases (85%), and venous contamination was absent or minor in 61 cases (84%). In 95% of cases, CT angiographic findings allowed optimal therapeutic management. The intraclass correlation coefficient ranged between 0.93 and 0.95, indicating excellent interobserver agreement. CONCLUSION With only 25 mL of iodinated contrast medium focused on the arterial phase, 64-detector CT angiography allowed satisfactory diagnostic and therapeutic management of nontraumatic SAH.
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Affiliation(s)
- Domitille Millon
- Department of Diagnostic and Therapeutic Neuroradiology, Centre Hospitalo Universitaire Nancy, Department of Anatomy, Faculty of Medicine, Université de Lorraine, Vandoeuvre Les Nancy, France.
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Gao Y, Du X, Liang L, Cao L, Yang Q, Li K. Evaluation of right ventricular function by 64-row CT in patients with chronic obstructive pulmonary disease and cor pulmonale. Eur J Radiol 2012; 81:345-53. [DOI: 10.1016/j.ejrad.2010.11.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2010] [Revised: 10/19/2010] [Accepted: 11/03/2010] [Indexed: 11/16/2022]
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Bulla S, Pache G, Bley T, Langer M, Blanke P. Simultaneous bilateral contrast injection in computed tomography pulmonary angiography. Acta Radiol 2012; 53:69-75. [PMID: 22156009 DOI: 10.1258/ar.2011.110244] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Computed tomography pulmonary angiography (CTPA) has evolved as the gold standard for diagnosing pulmonary embolism. However, subsegmental arteries are often not assessed to do insufficient attenuation. PURPOSE To evaluate the influence of simultaneous bilateral versus unilateral injection of a fixed amount of contrast media on pulmonary artery opacification and image quality in CTPA. MATERIAL AND METHODS In this institutional review board-approved prospective study, 180 patients (91 women, mean age 61.9 ± 16.5 years) referred for CTPA (100 kV) due to suspected pulmonary embolism were randomized in groups of 45 patients each, with either unilateral (A:4 mL/s; B:6 mL/s) or bilateral (C: 6 mL/s; D: 8 mL/s) (Y-shaped line) injection of 50 mL contrast media. Attenuation was assessed including the subsegmental arteries (4th order). Image quality was evaluated by two readers in consensus using a three-point grading scale (3 = excellent image quality, no artifacts, 1 = non-diagnostic). RESULTS Mean pulmonary artery attenuation was significantly higher with bilateral injection (1st to 3rd order: A: 303.6 ± 8.8HU; B: 371.1 ± 11.0HU vs. C: 443.2 ± 24.1HU; D: 562.3 ± 15.3HU, P < 0.001). Evaluation of subsegmental arteries was feasible for all patients in groups B-D, but only in 36/45 (80%) patients in group A. Subsegmental attenuation was significantly higher with bilateral injection (A: 284.7 ± 12.1HU; B: 367.4 ± 12.1HU vs. C: 494.2 ± 21.5HU; D: 562.3 ± 26.7HU, P < 0.001). Image quality was diagnostic for all patients but best for group C (A: 2.15 ± 0.4; B: 2.14 ± 0.5; C: 2.92 ± 0.3, and D: 2.51 ± 0.5). CONCLUSION Using the same amount of contrast media, bilateral injection yields higher pulmonary artery attenuation and better image quality than unilateral injection. This technique may improve subsegmental pulmonary artery assessment.
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Affiliation(s)
- Stefan Bulla
- Department of Diagnostic Radiology, University Hospital Freiburg
| | - Gregor Pache
- Department of Diagnostic Radiology, University Hospital Freiburg
| | - Thorsten Bley
- Department of Diagnostic Radiology, University Hospital Hamburg, Germany
| | - Mathias Langer
- Department of Diagnostic Radiology, University Hospital Freiburg
| | - Philipp Blanke
- Department of Diagnostic Radiology, University Hospital Freiburg
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Bashir MR, Weber PW, Husarik DB, Howle LE, Nelson RC. Improved aortic enhancement in CT angiography using slope-based triggering with table speed optimization: a pilot study. Int J Cardiovasc Imaging 2011; 28:1533-43. [PMID: 21898186 DOI: 10.1007/s10554-011-9945-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 08/25/2011] [Indexed: 10/17/2022]
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Nakaura T, Awai K, Yanaga Y, Namimoto T, Utsunomiya D, Hirai T, Sugiyama S, Ogawa H, Aoyama M, Yamashita Y. Low-dose contrast protocol using the test bolus technique for 64-detector computed tomography coronary angiography. Jpn J Radiol 2011; 29:457-65. [PMID: 21882087 DOI: 10.1007/s11604-011-0579-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 02/23/2011] [Indexed: 11/26/2022]
Abstract
PURPOSE We evaluated low-contrast injection protocols for coronary computed tomography angiography (CTA) using a 64-detector scanner and the test bolus technique. MATERIALS AND METHODS We randomly assigned 60 patients undergoing coronary CTA to one of two contrast material (CM) injection protocols. For the low-contrast dose protocol (P(low)), the patients received injections of iohexol-350 [0.7 ml/kg body weight (BW)] during 9 s, and the test-bolus technique was used. Under the conventional protocol (P(conv)), they received iohexol-350 (1.0 ml/kg BW) during 15 s, and bolus tracking was used. We compared the protocols for attenuation values in the ascending aorta and coronary arteries and for the amount of CM required. RESULTS There was no significant difference in the mean CT attenuation of the ascending aorta and coronary arteries between the P(low) and P(conv) groups. The amount of CM was significantly less with P(low) than with P(conv) [49.7 ± 6.4 ml (main bolus: 39.7 ± 6.4 ml) vs. 57.0 ± 10.1 ml, P < 0.01]. CONCLUSION With 64-detector CTA of the heart, the low-dose and short-injection-duration protocol with the test-injection technique provides vessel attenuation comparable to that obtained with the standard-dose protocol with the bolus-tracking technique.
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Affiliation(s)
- Takeshi Nakaura
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
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Saade C, Bourne R, Wilkinson M, Brennan P. Contrast Medium Administration and Parameters Affecting Bolus Geometry in Multidetector Computed Tomography Angiography: An Overview. J Med Imaging Radiat Sci 2011; 42:113-117. [DOI: 10.1016/j.jmir.2011.05.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 05/01/2011] [Accepted: 05/09/2011] [Indexed: 10/17/2022]
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Bertolini G, Prokop M. Multidetector-row computed tomography: Technical basics and preliminary clinical applications in small animals. Vet J 2011; 189:15-26. [DOI: 10.1016/j.tvjl.2010.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 06/03/2010] [Accepted: 06/04/2010] [Indexed: 11/27/2022]
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Cardiothoracic CT angiography: current contrast medium delivery strategies. AJR Am J Roentgenol 2011; 196:W260-72. [PMID: 21343473 DOI: 10.2214/ajr.10.5814] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Over the last decade, rapid technologic evolution in CT has resulted in improved spatial and temporal resolution and acquisition speed, enabling cardiothoracic CT angiography to become a viable and effective noninvasive alternative in the diagnostic algorithm. These new technologic advances have imposed new challenges for the optimization of contrast medium delivery and image acquisition strategies. CONCLUSION Thorough understanding of contrast medium dynamics is essential for the design of effective acquisition and injection protocols. This article provides an overview of the fundamentals affecting contrast enhancement, emphasizing the modifications to contrast material delivery protocols required to optimize cardiothoracic CT angiography.
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Bamberg F, Marcus R, Sommer W, Schwarz F, Nikolaou K, Becker CR, Reiser MF, Johnson TRC. Diagnostic image quality of a comprehensive high-pitch dual-spiral cardiothoracic CT protocol in patients with undifferentiated acute chest pain. Eur J Radiol 2010; 81:3697-702. [PMID: 21196093 DOI: 10.1016/j.ejrad.2010.11.032] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 11/19/2010] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To evaluate diagnostic image quality of high-pitch dual source comprehensive cardiothoracic CT protocol in patients presenting with acute undifferentiated chest pain. MATERIALS AND METHODS Consecutive symptomatic subjects (n=51) with undifferentiated acute chest pain underwent ECG-synchronized high-pitch dual-spiral chest CT angiography (Definition Flash, Siemens Medical Solutions, 2 × 100 kVp or 2 × 120 kV if BMI>30, collimation: 128 × 0.6mm, pitch: 3.2). Independent investigators determined the image quality of each cardiac and pulmonary vessel segment, measured contrast-to-noise-ratio (CNR), and determined radiation exposure. In addition, the prevalence of CT findings (pulmonary embolism (PE), aortic dissection (AD) and significant coronary stenosis (≥ 50%)) was determined. Univariate and multivariate analysis were performed to determine the subpopulation with highest diagnostic quality. RESULTS Among 51 subjects (66% male, average age: 63 ± 15.8), the prevalence of positive CT findings was moderate (overall: 11.7%). Overall, image quality of the pulmonary, aortic and coronary vasculature was good (1.26 ± 0.43 and CNR: 2.52) with an average radiation dose of 3.82 mSv and 3.2% of segments rated non-evaluable. The image quality was lowest in the coronary arteries (p=0.02), depending on the heart rate (r=0.52, p<0.001). In subjects with a heart rate of ≤ 65 bpm (n=30) subjective image quality and CNR of the coronary arteries were higher (1.6 ± 0.5 vs. 2.1 ± 0.5, p=0.03 and 1.21 ± 0.3 vs. 1.02 ± 0.3, p=0.05) with only 1.5% segments classified as non-evaluable. CONCLUSION High-pitch dual-spiral comprehensive cardiothoracic CT provides low radiation exposure with excellent image quality at heart rates ≤ 65 bpm. In subjects with higher heart rates, image quality of the aortic and pulmonary vasculature remains excellent, while the assessment of the coronary arteries degrades substantially.
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Affiliation(s)
- Fabian Bamberg
- Department of Clinical Radiology, Ludwig-Maximilians University, Klinikum Grosshadern, Munich, Germany.
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Keeling AN, Farrelly C, Carr JC, Yaghmai V. Technical considerations for lower limb multidetector computed tomographic angiography. Vasc Med 2010; 16:131-43. [PMID: 21138985 DOI: 10.1177/1358863x10388347] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Multidetector computed tomography (MDCT) enables imaging of the entire arterial tree non-invasively. Optimal technical considerations for performing MDCT angiography (MDCTA) are essential for accurate diagnosis and atherosclerotic disease stratification. This review article focuses on the various technical aspects necessary for peripheral computed tomographic angiography (CTA) acquisition. Common clinical indications for peripheral MDCTA and the latest scan protocols are described. The essential issue of radiation dose reduction is discussed, along with methods of optimal contrast bolus detection and delivery. Post-processing techniques are also presented. Previously, digital subtraction angiography was the only established reliable imaging technique to quantify atherosclerotic disease load; however, MDCTA may now challenge this old gold standard, along with other non-invasive techniques such as magnetic resonance angiography (MRA).
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Affiliation(s)
- Aoife N Keeling
- Department of Radiology, Division of Cardiovascular Imaging, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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Kim EY, Yeh DW, Choe YH, Lee WJ, Lim HK. Image quality and attenuation values of multidetector CT coronary angiography using high iodine-concentration contrast material: a comparison of the use of iopromide 370 and iomeprol 400. Acta Radiol 2010; 51:982-9. [PMID: 20849317 PMCID: PMC2981075 DOI: 10.3109/02841851.2010.509740] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Background: Effects of high iodine-concentration contrast material on the image quality of coronary CT angiography (CCTA) have not been well evaluated. Purpose: To compare the image quality and attenuation values of CCTA between patients administered iopromide 370 and iomeprol 400 with the use of 64-slice multidetector CT. Material and Methods: Patients were prospectively enrolled and were randomized into two groups (group A, 151 patients received iopromide 370, iodine flux = 1.48 g I/s; group B, 146 patients received iomeprol 400, iodine flux = 1.60 g I/s). CT attenuation was measured in the coronary arteries and great arteries and measurements were standardized based on an iodine flux of 1.5 0 g I/s. The image quality of 15 coronary artery segments was graded by two radiologists in consensus with the use of a four-point scale (1 = excellent to 4 = poor enhancement). Non-parametric statistical approaches were used to compare the two groups. Results: The median attenuation values in the coronary arteries were 454 HU and 464 HU for iopromide 370 and iomeprol 400, respectively, and they did not differ (P = 0.26). When standardizing for an iodine flux, significantly higher attenuation values were found for iopromide 370 (median = 460 HU, range = 216-791 HU) compared with iomeprol 400 (median = 435 HU, range = 195—758 HU) (P = 0.006). The median image quality score of coronary arterial segments was 1 (range 1—2) for both groups (P = 0.84). Conclusion: The attenuation values in the coronary arteries after injection of the same amount of two high iodine-concentration contrast materials at the same flow rate with different iodine fluxes are similar with no difference in image quality. With standardization for an iodine flux, the attenuation is significantly higher when using iopromide 370.
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Affiliation(s)
- Eun Young Kim
- Department of Radiology and Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Department of Radiology, Gachon University Gil Hospital, Incheon, Republic of Korea
| | - Dae Wook Yeh
- Department of Radiology and Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Yeon Hyeon Choe
- Department of Radiology and Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Won Jae Lee
- Department of Radiology and Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Hyo Keun Lim
- Department of Radiology and Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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Abstract
Although catheter angiography remains the accepted gold standard for imaging of the renal vascular system, rapid progress in cross-sectional imaging techniques has caused a paradigm shift in many diagnostic algorithms toward noninvasive techniques such as computed tomographic angiography (CTA). CTA's cross-sectional imaging techniques provide an opportunity for comprehensive renal investigation that would be impossible with angiography alone. While other competing noninvasive technologies such as ultrasound and magnetic resonance angiography can be used successfully in renal imaging, the benefits of CTA are substantial, including high spatial and temporal resolution, widespread availability, implantable device compatibility, and easy technical reproducibility. This article describes the technical considerations relevant to CTA of the renal vascular system, postprocessing algorithms for volumetric data, and numerous specific applications.
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Affiliation(s)
- Peter S Liu
- Department of Radiology, University of Michigan Medical Center, Ann Arbor, MI 48109-0030, USA.
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Bae KT. Intravenous contrast medium administration and scan timing at CT: considerations and approaches. Radiology 2010; 256:32-61. [PMID: 20574084 DOI: 10.1148/radiol.10090908] [Citation(s) in RCA: 646] [Impact Index Per Article: 46.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The continuing advances in computed tomographic (CT) technology in the past decades have provided ongoing opportunities to improve CT image quality and clinical practice and discover new clinical CT imaging applications. New CT technology, however, has introduced new challenges in clinical radiology practice. One of the challenges is with intravenous contrast medium administration and scan timing. In this article, contrast medium pharmacokinetics and patient, contrast medium, and CT scanning factors associated with contrast enhancement and scan timing are presented and discussed. Published data from clinical studies of contrast medium and physiology are reviewed and interpreted. Computer simulation data are analyzed to provide an in-depth analysis of various factors associated with contrast enhancement and scan timing. On the basis of basic principles and analysis of the factors, clinical considerations and modifications to protocol design that are necessary to optimize contrast enhancement for common clinical CT applications are proposed.
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Affiliation(s)
- Kyongtae T Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
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Rutten A, Meijs MFL, de Vos AM, Seidensticker PR, Prokop M. Biphasic contrast medium injection in cardiac CT: moderate versus high concentration contrast material at identical iodine flux and iodine dose. Eur Radiol 2010; 20:1917-25. [PMID: 20306079 PMCID: PMC2899014 DOI: 10.1007/s00330-010-1752-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 01/04/2010] [Accepted: 02/07/2010] [Indexed: 02/06/2023]
Abstract
Objective To prospectively investigate the influence of contrast material concentration on enhancement in cardiac CT by using a biphasic single-injection protocol. Methods Sixty-four-row multidetector cardiac CT angiography was performed in 159 patients randomised to a moderate or high contrast medium concentration. Contrast material injection included a first phase for enhancement of the coronary arteries and a second phase, at half the iodine flux, targeted at enhancement of the right ventricle. Contrast medium injection was followed by a saline flush. For both concentrations, injection duration (and thus total iodine dose) was adapted to the duration of the CT data acquisition and iodine flux was adjusted to patient weight. Attenuation was measured at various levels in the heart and vessels and the two concentrations compared, overall and per weight group. Results Enhancement of the aorta and left ventricle was significantly greater with the moderate than with the high concentration contrast medium. This remained true for the two higher weight groups. No difference was found in the lowest weight group or in the right ventricle and pulmonary outflow tract. Conclusion With a biphasic injection protocol, enhancement of the aorta and left ventricle was weaker with the higher concentration of contrast material.
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Affiliation(s)
- Annemarieke Rutten
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
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Behrendt FF, Pietsch H, Jost G, Sieber MA, Keil S, Plumhans C, Seidensticker P, Günther RW, Mahnken AH. Intra-individual comparison of different contrast media concentrations (300 mg, 370 mg and 400 mg iodine) in MDCT. Eur Radiol 2010; 20:1644-50. [PMID: 20182733 DOI: 10.1007/s00330-010-1717-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 10/19/2009] [Accepted: 11/04/2009] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare intra-individual contrast enhancement in multi-detector-row computed tomography (MDCT) using contrast media (CM) containing 300, 370 and 400 mg iodine per ml (mgI/ml). METHODS Six pigs underwent repeated chest MDCT using three different CM (iopromide 300, iopromide 370, iomeprol 400). An identical iodine delivery (IDR) rate of 1.5 gI/s and a constant total iodine dose of 300 mg/kg body weight were used. Dynamic CT were acquired at the level of the pulmonary artery, and the ascending and descending aorta. After the time enhancement curves were computed, the pulmonary and aortic peak enhancement, time to peak and plateau time above 300 HU were calculated. RESULTS Intra-individual peak contrast enhancement was significantly higher for the 300 mgI/ml contrast medium compared with the 370 and 400 mgI/ml media: pulmonary trunk 595 HU vs 516 HU (p = 0.0093) vs 472 HU (p = 0.0005), and aorta 505 HU vs 454 HU (p = 0.0008) vs 439 HU (p = 0.0001), respectively. Comparison of time to peaks showed no significant difference. Plateau times were significantly longer for the 300 mgI/ml than for the 370 and 400 mgI/ml CM at all anatomical sites. CONCLUSION Given normalised IDR and total iodine burden, the use of CM with a standard concentration with 300 mg iodine/ml provides improved contrast enhancement compared with highly concentrated CM in the chest.
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Affiliation(s)
- Florian F Behrendt
- Department of Diagnostic Radiology, University Hospital, RWTH Aachen University, Aachen, Germany.
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Hybrid-repair of thoraco-abdominal or juxtarenal aortic aneurysm: what the radiologist should know. Eur Radiol 2009; 20:1011-22. [DOI: 10.1007/s00330-009-1603-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 06/26/2009] [Accepted: 08/06/2009] [Indexed: 11/25/2022]
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Vernhet Kovacsik H, Jacquier A, Gaubert JY, Paul J, Dupouy P, Cluzel P, Hamon M. [Technological advances in cardiac CT]. JOURNAL DE RADIOLOGIE 2009; 90:1161-1171. [PMID: 19752826 DOI: 10.1016/s0221-0363(09)73262-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The SFR-SFC presents guidelines dedicated to cardiac and coronary imaging using CT in the area of indications, technological requirement including both hardware and software, patient conditioning, CT protocols and related results concerning radiation dose, image quality and diagnostic value. These guidelines are based either on up-dated medical literature proofs and/or on expert consensus.
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Affiliation(s)
- H Vernhet Kovacsik
- Service de Radiologie, Hôpital Arnaud de Villeneuve, 371 Avenue Doyen Gaston Giraud, 34295 Montpellier cedex 05, France.
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Évolutions technologiques en tomodensitométrie cardiaque. ARCHIVES OF CARDIOVASCULAR DISEASES SUPPLEMENTS 2009. [DOI: 10.1016/s1878-6480(09)70354-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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