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Sayin B, Durakoğlugil T, Akmangit İ, Durakoğlugil ME, Vural M, Elverici E. Multiple simultaneous venous and arterial thromboses in a patient with factor V Leiden disorder: Detection by multislice computed tomography. Interv Med Appl Sci 2015; 7:38-41. [PMID: 25838926 DOI: 10.1556/imas.6.2014.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 08/27/2014] [Accepted: 10/06/2014] [Indexed: 12/22/2022] Open
Abstract
Arterial thrombosis is extremely rare in patients with factor V Leiden (FVL) mutation. Recent advances in multislice computed tomography (MSCT) technology facilitated diagnosis of thromboembolic events accurately without delay. We report a patient with FVL mutation and acute bilateral lower extremity deep venous thromboses, pulmonary thromboembolism, and acute left anterior descending artery thrombosis, all diagnosed by MSCT. MSCT has been utilized for prompt diagnosis of the concomitant thrombotic pathologies simultaneously.
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Diagnostic performance of two types of low radiation exposure protocol for prospective ECG-triggering multidetector computed tomography angiography in assessment of coronary artery bypass graft. Int J Cardiol 2012; 157:63-9. [DOI: 10.1016/j.ijcard.2010.11.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Revised: 11/22/2010] [Accepted: 11/29/2010] [Indexed: 11/17/2022]
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3
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Pontone G, Andreini D, Bartorelli A, Bertella E, Mushtaq S, Foti C, Formenti A, Chiappa L, Annoni A, Cortinovis S, Baggiano A, Conte E, Bovis F, Veglia F, Ballerini G, Agostoni P, Fiorentini C, Pepi M. Feasibility and diagnostic accuracy of a low radiation exposure protocol for prospective ECG-triggering coronary MDCT angiography. Clin Radiol 2012; 67:207-15. [DOI: 10.1016/j.crad.2011.07.042] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 06/30/2011] [Accepted: 07/05/2011] [Indexed: 02/05/2023]
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Duymuş M, Kayan M, Çetin M, Türker Y, Yılmaz Ö, Munduz M, Yaşar S. Evaluation of Atherosclerotic Plaque, Coronary Stent and Coronary By-Pass Grafts with 128-Slice CT and Technical Optimization: Our Single Center Experiences. ELECTRONIC JOURNAL OF GENERAL MEDICINE 2012. [DOI: 10.29333/ejgm/82549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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5
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Shapiro BP, Young PM, Kantor B, Choe YH, McCollough CH, Gerber TC. Radiation dose reduction in CT coronary angiography. Curr Cardiol Rep 2011; 12:59-67. [PMID: 20425185 DOI: 10.1007/s11886-009-0074-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
During recent years, technologic advancements in computed tomography (CT) have allowed robust cardiac and coronary imaging. Small, mobile cardiac structures such as the coronary arteries can now be imaged directly and noninvasively with high precision. Given the fact that coronary CT angiography (CCTA) can detect preclinical calcified and noncalcified atherosclerosis, there is potential to revolutionize the management of ischemic heart disease by refining risk stratification and improving outcomes in various clinical settings. However, despite this progress, CT has come under scrutiny as concerns about the level and risk of the radiation exposure of the population grow. Although there are no data to support a direct association between CT imaging and risk of future cancer, health care practitioners should make every effort to minimize radiation exposure to their patients. The purpose of this article is to describe techniques that can reduce radiation dose to patients during CCTA but maintain diagnostic image quality.
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Affiliation(s)
- Brian P Shapiro
- Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA
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6
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Law WY, Yang CC, Chen LK, Huang TC, Lu KM, Wu TH, Mok GS. Retrospective gating vs. prospective triggering for noninvasive coronary angiography: Assessment of image quality and radiation dose using a 256-slice CT scanner with 270 ms gantry rotation. Acad Radiol 2011; 18:31-9. [PMID: 21145027 DOI: 10.1016/j.acra.2010.07.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 07/23/2010] [Accepted: 07/28/2010] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To report our clinical experience with a 256-slice multidetector computed tomography (MDCT) with a 270-ms gantry rotation system in performing CT coronary angiograms (CTCA) using both prospectively gated step and shoot (PGSS) and retrospectively gated helical (RGH) techniques. MATERIALS AND METHODS We studied 252 patients who received CTCA; 126 patients having mean heart rate (HR) of 72.1 were imaged with RGH CTCA and 126 patients having mean HR of 58.7 were imaged with PGSS CTCA. For patients with a prescan HR ≤70 beats/min, a PGSS acquisitions trigger was used, whereas patients whose prescan HR was >70 beats/min were imaged using an RGH acquisition. The blood vessel accessibility of both PGSS and RGH techniques was evaluated by grading the image quality score from 1 (no motion artifacts) to 4 (severe motion artifacts preventing diagnosis) for each coronary artery segment. Radiation doses of the techniques were also compared. RESULTS In both groups, more than 50% of segments received the best imaging score. The overall image quality scores for RGH and PGSS groups were 1.522 ± 0.317 and 1.500 ± 0.374, respectively. There was no significant difference in right coronary artery, left anterior descending artery, and left circumflex artery image quality between the two groups. Only 0.1% of segments were nonevaluative with the PGSS technique and all segments were evaluative with RGH. PGSS was associated with a 62% reduction in effective radiation dose as compared to RGH (PGSS, 5.1 mSv; RGH, 13.2 mSv). CONCLUSIONS There is no significant difference in image quality between PGSS and RGH in this study. Although providing similar image quality as RGH, PGSS was associated with a 62% reduction in effective radiation dose. Further study to confirm the diagnostic accuracy as compared to coronary artery angiography is warranted.
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Gerber TC. Emergency department assessment of acute-onset chest pain: contemporary approaches and their consequences. Mayo Clin Proc 2010; 85:309-13. [PMID: 20360290 PMCID: PMC2848418 DOI: 10.4065/mcp.2010.0141] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Thomas C. Gerber
- Division of Cardiovascular Diseases, Mayo Clinic in FloridaJacksonville
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Winchester DE, Wymer DC, Shifrin RY, Kraft SM, Hill JA. Responsible use of computed tomography in the evaluation of coronary artery disease and chest pain. Mayo Clin Proc 2010; 85:358-64. [PMID: 20360294 PMCID: PMC2848424 DOI: 10.4065/mcp.2009.0652] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Many options are available to clinicians for the noninvasive evaluation of the cardiovascular system and patient concerns about chest discomfort. Cardiac computed tomography (CT) is a rapidly advancing field of noninvasive imaging. Computed tomography incorporates coronary artery calcium scoring, coronary angiography, ventricular functional analysis, and information about noncardiac thoracic anatomy. We searched the PubMed database and Google from inception to September 2009 for resources on the accuracy, risk, and predictive capacity of coronary artery calcium scoring and CT coronary angiography and have reviewed them herein. Cardiac CT provides diagnostic information comparable to echocardiography, nuclear myocardial perfusion imaging, positron emission tomography, and magnetic resonance imaging. A cardiac CT study can be completed in minutes. In patients with a nondiagnostic stress test result, cardiac CT can preclude the need for invasive angiography. Prognostic information portends excellent outcomes in patients with normal study results. Use of cardiac CT can reduce health care costs and length of emergency department stays for patients with chest pain. Cardiac CT examination provides clinically relevant information at a radiation dose similar to well-established technologies, such as nuclear myocardial perfusion imaging. Advances in technique can reduce radiation dose by 90%. With appropriate patient selection, cardiac CT can accurately diagnose heart disease, markedly decrease health care costs, and reliably predict clinical outcomes.
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Affiliation(s)
- David E Winchester
- Department of Medicine, Division of Cardiology, University of Florida College of Medicine, Gainesville, FL 32610-0277, USA.
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9
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Abstract
As a result of the changes in use of imaging procedures that rely on ionizing radiation, the collective dose has increased by over 700%, and the annual per-capita dose by almost 600% in recent years. It is possible that this growing use may have significant effects on public health. Although uncertainties exist related to the accuracy of estimated radiation exposure and biologic risk, there are measures that can be taken by the referring and the performing health care provider to reduce the potential risks while maintaining diagnostic accuracy. This article reviews the existing data regarding biologic hazards of radiation exposure associated with medical diagnostic testing, the methodologies used to estimate radiation exposure and dose, and the measures that can be taken to effectively reduce that exposure.
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Affiliation(s)
- Thomas C Gerber
- Division of Cardiovascular Diseases, Mayo Clinic, Jacksonville, FL 32224, USA.
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Bartnes K, Sildnes T, Iqbal A, Dahl-Eriksen O, Trovik T, Steigen TK, Mortensen R, Mannsverk JT, Sørlie DG, Myrmel T. Coronary bypass graft patency cannot be determined by multidetector spiral computed tomography. SCAND CARDIOVASC J 2009; 40:83-6. [PMID: 16608777 DOI: 10.1080/14017430600566039] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Angiography by selective catheterization is the reference standard for coronary bypass graft patency assessment but carries a risk of serious complications. We have investigated whether 16-slice multidetector spiral computed tomography (MDCT) can substitute for selective angiography. DESIGN Two to three years after coronary artery bypass grafting, 45 patients with a total of 156 bypasses (100 single and 28 sequential grafts) were examined with both MDCT and conventional selective angiography on the same day. The bypasses were classified as patent, stenotic or occluded. RESULTS The likelihood ratio for MDCT-detected occlusion was 40, reflecting a fairly high combined sensitivity and specificity. However, 24% of the distal anastomoses could not be evaluated by MDCT, mainly because of respiratory movements, artifacts due to metal clips, and small vessel dimensions. Moreover, seven out of 117 bypasses (6%) deemed evaluable by MDCT were wrongly classified by this method. CONCLUSIONS At present, 16-slice MDCT cannot replace selective angiography for assessment of coronary bypass graft patency since 24% of bypasses could not be evaluated by this method, and an error rate of 6% is unacceptable.
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Affiliation(s)
- Kristian Bartnes
- Department of Cardiothoracic and Vascular Surgery, University Hospital North Norway, Tromsø, Norway.
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Bluemke DA, Achenbach S, Budoff M, Gerber TC, Gersh B, Hillis LD, Hundley WG, Manning WJ, Printz BF, Stuber M, Woodard PK. Noninvasive coronary artery imaging: magnetic resonance angiography and multidetector computed tomography angiography: a scientific statement from the american heart association committee on cardiovascular imaging and intervention of the council on cardiovascular radiology and intervention, and the councils on clinical cardiology and cardiovascular disease in the young. Circulation 2008; 118:586-606. [PMID: 18586979 DOI: 10.1161/circulationaha.108.189695] [Citation(s) in RCA: 351] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Bordier L, Garcia C, Goasdoué P, Mayaudon H, Dupuy O, Guiraudet O, Bauduceau B. What is the role of computed tomographic coronary angiography in diabetic patients? DIABETES & METABOLISM 2008; 34:26-32. [DOI: 10.1016/j.diabet.2007.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 07/26/2007] [Accepted: 08/16/2007] [Indexed: 11/26/2022]
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Abstract
Technological advances have made cardiac computed tomography (CT) an important player in cardiac imaging. Cardiac CT has become a powerful tool in the armamentarium of cardiac risk stratification assessment of intermediate-risk patients, bypass grafts, stents, and anomalous coronary arteries. With advancement in accuracy and reliability, cardiac CT is becoming mainstream in everyday clinical cardiology. It is up to the clinician to use the technology effectively and appropriately. It is certain that cardiac CT technology will continue to improve.
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Wesarg S, Khan MF, Firle EA. Localizing calcifications in cardiac CT data sets using a new vessel segmentation approach. J Digit Imaging 2007; 19:249-57. [PMID: 16741661 PMCID: PMC3045143 DOI: 10.1007/s10278-006-9947-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
The new generation of multislice computed tomography (CT) scanners allows for the acquisition of high-resolution images of the heart. Based on that image data, the heart can be analyzed in a noninvasive way-improving the diagnosis of cardiovascular malfunctions on one hand, and the planning of an eventually necessary intervention on the other. One important parameter for the evaluation of the severity of a coronary artery disease is the number and localization of calcifications (hard plaques). This work presents a method for localizing these calcifications by employing a newly developed vessel segmentation approach. This extraction technique has been developed for, and tested with, contrast-enhanced CT data sets of the heart. The algorithm provides enough information to compute the vessel diameter along the extracted segment. An approach for automatically detecting calcified regions that combines diameter information and gray value analysis is presented. In addition, specially adapted methods for the visualization of these analysis results are described.
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Affiliation(s)
- Stefan Wesarg
- Department of Cognitive Computing & Medical Imaging, Darmstadt, Germany.
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Bousse A, Boldak C, Toumoulin C, Yang G, Laguitton S, Boulmier D. Coronary extraction and characterization in multi-detector computed tomography. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.rbmret.2007.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Budoff MJ, Shinbane JS, Child J, Carson S, Chau A, Liu SH, Mao S. Multiphase contrast medium injection for optimization of computed tomographic coronary angiography. Acad Radiol 2006; 13:159-65. [PMID: 16428050 DOI: 10.1016/j.acra.2005.09.087] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2005] [Revised: 09/13/2005] [Accepted: 09/21/2005] [Indexed: 12/01/2022]
Abstract
RATIONALE AND OBJECTIVES Electron beam angiography is a minimally invasive imaging technique. Adequate vascular opacification throughout the study remains a critical issue for image quality. We hypothesized that vascular image opacification and uniformity of vascular enhancement between slices can be improved using multiphase contrast medium injection protocols. MATERIALS AND METHODS We enrolled 244 consecutive patients who were randomized to three different injection protocols: single-phase contrast medium injection (Group 1), dual-phase contrast medium injection with each phase at a different injection rate (Group 2), and a three-phase injection with two phases of contrast medium injection followed by a saline injection phase (Group 3). Parameters measured were aortic opacification based on Hounsfield units and uniformity of aortic enhancement at predetermined slices (locations from top [level 1] to base [level 60]). RESULTS In Group 1, contrast opacification differed across seven predetermined locations (scan levels: 1st versus 60th, P < .05), demonstrating significant nonuniformity. In Group 2, there was more uniform vascular enhancement, with no significant differences between the first 50 slices (P > .05). In Group 3, there was greater uniformity of vascular enhancement and higher mean Hounsfield units value across all 60 images, from the aortic root to the base of the heart (P < .05). CONCLUSIONS The three-phase injection protocol improved vascular opacification at the base of the heart, as well as uniformity of arterial enhancement throughout the study.
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Affiliation(s)
- Matthew Jay Budoff
- Division of Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA 90502, USA.
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17
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Gerber TC, Breen JF, Kuzo RS, Kantor B, Williamson EE, Safford RE, Morin RL. Computed Tomographic Angiography of the Coronary Arteries: Techniques and Applications. Semin Ultrasound CT MR 2006; 27:42-55. [PMID: 16562571 DOI: 10.1053/j.sult.2005.11.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Computed tomographic coronary angiography (CT-CA) is a direct but minimally invasive method of visualizing coronary arteries. Multidetector-row computed tomography (MDCT) is currently the CT modality most commonly used for coronary artery imaging. MDCT has been successfully used to detect stenoses in coronary arteries and coronary artery bypass grafts and to assess congenital coronary anomalies. Patients should not undergo CT-CA with MDCT if they have an irregular heart rhythm, a heart rate greater than 70 beats/min, and contraindications to pharmacologic agents for heart rate control, or if they have severe coronary artery disease or are likely to require revascularization.
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Affiliation(s)
- Thomas C Gerber
- Division of Cardiovascular Diseases, Mayo Clinic, Jacksonville, FL 32224, USA.
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18
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Soon KH, Kelly AM, Cox N, Chaitowitz I, Bell KW, Lim YL. Non-invasive multislice computed tomography coronary angiography for imaging coronary arteries, stents and bypass grafts. Intern Med J 2006; 36:43-50. [PMID: 16409312 DOI: 10.1111/j.1445-5994.2005.00974.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Abstract Multislice computed tomography (MSCT) is evolving rapidly and available data suggest that MSCT coronary angiography may be a reliable and accurate non-invasive imaging modality of coronary arteries. Current generations of MSCT scanners have high sensitivity and specificity for diagnosing native coronary artery disease and coronary bypass graft occlusion. The performance of MSCT in the evaluation of stent patency is still being assessed. In comparison with conventional selective coronary angiography (SCA), MSCT is non-invasive, cheaper and it has the advantages of imaging plaque compositions as well as assessment of luminal patency. Nevertheless, the role of MSCT in the management of coronary artery disease is yet to be fully defined.
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Affiliation(s)
- K H Soon
- Centre for Cardiovascular Therapeutics, Western Hospital, Melbourne, Victoria, Australia.
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Memisoglu E, Ropers D, Hobikoglu G, Tepe MS, Labovitz AJ. Usefulness of electron beam computed tomography for diagnosis of an anomalous origin of a coronary artery from the opposite sinus. Am J Cardiol 2005; 96:1452-5. [PMID: 16275198 DOI: 10.1016/j.amjcard.2005.07.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2005] [Revised: 07/01/2005] [Accepted: 07/01/2005] [Indexed: 11/27/2022]
Abstract
The ectopic origination of a coronary artery from the opposite sinus is a rare condition, often discovered as an incidental finding during invasive catheter angiography performed for the evaluation of atherosclerotic coronary artery disease. Although most patients lack hemodynamic significance, a small fraction of these anomalies have been associated with sudden cardiac death and ischemic complications. The exact anatomic definition of the anomalous coronary artery and its course, especially in relation to the ascending aorta and the pulmonary trunk, is therefore crucial for every imaging modality that attempts coronary artery visualization. To underline the potential of 3-dimensional electron-beam computed tomography as an important complement to invasive angiography in the delineation of anomalous coronary arteries, this study focused on the potentially malignant ectopic contralateral origination of a coronary artery.
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Affiliation(s)
- Esat Memisoglu
- Department of Radiology, St. Louis University Hospital, St. Louis, Missouri, USA.
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Ratti C, Barbieri A, Ligabue G, Grimaldi T, Chiurlia E, Rossi R, Modena MG. Non-invasive, three-dimensional visualization of coronary artery bypass grafts by multislice spiral computed tomography. Int J Cardiol 2005; 99:157-9. [PMID: 15721521 DOI: 10.1016/j.ijcard.2003.12.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2003] [Revised: 11/25/2003] [Accepted: 12/25/2003] [Indexed: 10/26/2022]
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Gerber TC, Kuzo RS, Morin RL. Techniques and parameters for estimating radiation exposure and dose in cardiac computed tomography. Int J Cardiovasc Imaging 2005; 21:165-76. [PMID: 15915949 DOI: 10.1007/s10554-004-5338-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
With increasing clinical use of cardiac CT imaging it is important that all health care providers referring for or administering such examinations are familiar with the concepts and values of radiation dosimetry in CT as well as with the basic principles of radiation protection. There are important technical differences pertinent to radiation dose between the CT scanner types that are currently being used for imaging of the heart and coronary arteries. As a result of these differences, the radiation dose typically is higher when a cardiac examination is performed with multidetector-row CT (MDCT) than when it is performed with electron beam CT. Several techniques have been described to reduce radiation dose of MDCT imaging by varying the X-ray tube current during a CT examination. The volume computed tomographic dose index (CTDIvol), the dose length product (DLP), and the effective dose (E) are the most useful parameters to describe and compare radiation doses received from cardiac CT examinations. When comparing radiation doses between scanning protocols and scanner types, the degree of image noise must be considered. Diagnostic, rather than aesthetic, quality of images should be the most important factor guiding the development of scanning protocols for cardiac CT imaging. Cardiac CT examinations should be ordered only by qualified health care providers, and the ordering clinicians should be aware of their responsibility of weighing risks of the radiation exposure against the expected benefits.
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Affiliation(s)
- Thomas C Gerber
- Division of Cardiovascular Diseases, Mayo Clinic, Jacksonville, FL 32224, USA.
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22
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Gerber TC, Stratmann BP, Kuzo RS, Kantor B, Morin RL. Effect of Acquisition Technique on Radiation Dose and Image Quality in Multidetector Row Computed Tomography Coronary Angiography With Submillimeter Collimation. Invest Radiol 2005; 40:556-63. [PMID: 16024994 DOI: 10.1097/01.rli.0000170628.69792.cb] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
RATIONALE AND OBJECTIVES We sought to examine effects of tube voltage and current on radiation dose and image quality for minimally invasive coronary angiography with a 16-slice multidetector row computed tomography (MDCT) scanner. MATERIALS AND METHODS We scanned the phantom used in the American College of Radiology Computed Tomography Accreditation Program at tube voltages of 80 and 120 kVp at 550, 650, and 750 mAseff, with and without a reduction in radiation dose by electrocardiographically (ECG) controlled tube current modulation (ECG pulsing). RESULTS Without ECG pulsing, the effective dose was 3 to 13 mSv. On average, a 50% increase in tube voltage led to increased radiation dose (215%), contrast-to-noise ratio (150%), and decreased image noise (-48%). On average, a 17% increase in mAseff led to increased radiation dose (17%) and contrast-to-noise ratio (4%) and decreased image noise (-9%). Dose reduction by ECG pulsing (simulated heart rate, 70 beats per minute) was 28%. With ECG pulsing, noise in images reconstructed during ventricular systole was double that in images reconstructed during ventricular diastole. CONCLUSIONS These quantitative findings about the relationships among scan acquisition parameters, radiation dose, and image quality have practical implications for using ECG pulsing to reduce radiation doses in MDCT coronary angiography.
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Affiliation(s)
- Thomas C Gerber
- Department of Diagnostic Radiology, Mayo Clinic, Jacksonville, FL 32224, USA.
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23
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Schroeder S, Kuettner A, Beck T, Kopp AF, Herdeg C, Heuschmid M, Burgstahler C, Seipel L, Claussen CD. Usefulness of noninvasive MSCT coronary angiography as first-line imaging technique in patients with chest pain: initial clinical experience. Int J Cardiol 2005; 102:469-75. [PMID: 16004893 DOI: 10.1016/j.ijcard.2004.05.057] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2004] [Accepted: 05/05/2004] [Indexed: 12/19/2022]
Abstract
PURPOSE Comparative studies with invasive coronary angiography (ICA) indicated a good sensitivity and specificity in the noninvasive detection of coronary artery disease (CAD) using Multi-slice spiral computed tomography coronary angiography (MS-CTA). The aim was to investigate the usefulness of MS-CTA as first-line imaging technique in patients (pts) with known or suspected CAD and low to intermediate probability of a severe coronary lesion. We report on our initial clinical experience using MS-CTA without compelled ICA. MATERIAL AND METHODS One hundred thirty six patients with chest pain underwent MS-CTA on an outpatient basis (age 60+/-10, suspicion of CAD: n=95, suspicion of restenosis: n=24, after CABG: n=17). Based on the MS-CTA results, a recommendation concerning further diagnostics and therapy was given to each pt. A telephone interview was performed after 455+/-166 days to evaluate the further clinical course. RESULTS Per pt, 8.2+/-2.7 coronary segments could be evaluated. Based on the MSCT results, the presence of flow-limiting stenoses was excluded in n=77 (57%) pts (group I). An additional ICA was recommended in n=59 (43%) pts (group II). An ICA had been performed in meantime in 27/136 (20%) pts, and could be avoided in the majority of pts. Nevertheless, 58/136 (42%) pts reported on improved clinical symptoms and 42/136 (31%) pts of improved quality of life. CONCLUSIONS MS-CTA was found to be useful to evaluate the need and to reduce the total number of ICA in pts with unclear chest pain. It appears to be the first noninvasive modality, which might be used on a clinical routine basis in selected groups of pts.
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Affiliation(s)
- Stephen Schroeder
- Department of Internal Medicine, Division of Cardiology, Otfried-Mueller-Str. 10, 72076 Tuebingen, Germany.
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Lawler LP, Pannu HK, Fishman EK. MDCT Evaluation of the Coronary Arteries, 2004: How We Do It—Data Acquisition, Postprocessing, Display, and Interpretation. AJR Am J Roentgenol 2005; 184:1402-12. [PMID: 15855087 DOI: 10.2214/ajr.184.5.01841402] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Cardiac CT is rapidly becoming part of clinical practice. The objective of this article is to discuss and illustrate the current practice of coronary artery MDCT, including data acquisition, postprocessing, image display, and interpretation. The practice described reflects our experience with a series of patients referred in routine clinical practice. CONCLUSION The reader should gain an insight into the current clinical application of coronary artery CT.
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Affiliation(s)
- Leo P Lawler
- Department of Radiology and Radiological Science, Johns Hopkins University, 601 N Caroline St., Rm. 3254, Baltimore, MD 21287-0801, USA
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Beck T, Burgstahler C, Kuettner A, Kopp AF, Heuschmid M, Claussen CD, Schroeder S. Clinical use of multislice spiral computed tomography in 210 highly preselected patients: experience with 4 and 16 slice technology. Heart 2005; 91:1423-7. [PMID: 15761053 PMCID: PMC1769195 DOI: 10.1136/hrt.2004.049817] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVE To report an initial experience with multislice spiral computed tomography (MSCT) coronary imaging, as well as differences in diagnostic accuracy between 4 slice and 16 slice MSCT technology. METHODS AND RESULTS 210 patients underwent MSCT coronary angiography (4 slices, n = 120; 16 slices, n = 90; suspicion of coronary artery disease, n = 158; suspicion of restenosis, n = 52). Recommendations for further diagnostic tests were based on the MSCT results. Patients were interviewed by telephone after a mean (SD) of 449 (169) days to evaluate their further clinical course. MSCT detected significant lesions in 90 of 210 (43%) patients and invasive coronary angiography (ICA) was recommended. MSCT excluded significant lesions in 120 of 210 (57%) patients. ICA was actually performed in 44 of 210 (21%) patients (corresponding results, 27 of 44 (61%); false positive, 11 of 44 (25%); false negative, 6 of 44 (14%)). No significant differences were found between 4 and 16 slice imaging. No major cardiac event occurred during follow up. CONCLUSIONS MSCT was found to be useful to evaluate the need for invasive diagnostic procedures. However, the false negative results underline that further improvements of image quality are required before MSCT can replace ICA in carefully selected patients.
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Affiliation(s)
- T Beck
- Division of Cardiology, Department of Internal Medicine, Eberhard-Karls University, Tuebingen, Germany
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Marten K, Funke M, Rummeny EJ, Engelke C. Electrocardiographic assistance in multidetector CT of thoracic disorders. Clin Radiol 2005; 60:8-21. [PMID: 15642288 DOI: 10.1016/j.crad.2004.03.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2003] [Revised: 02/27/2004] [Accepted: 03/03/2004] [Indexed: 01/15/2023]
Abstract
ECG-synchronized multislice spiral CT (MSCT) allows a significant reduction of cardiac motion artefacts and as a result a virtually artefact-free display of intrathoracic structures. With their advantages in imaging geometry and continuous spiral image acquisition multislice CT scanners provide superior image quality and spatial resolution in these patients. Possible clinical applications for ECG assistance in MSCT include CT angiography of the coronary arteries, functional cardiac CT imaging and imaging of the cardiac valves, CT angiography of the aorta or pulmonary vascular tree as well as ECG-gated imaging of the lung parenchyma. Prospective ECG triggering and retrospectively ECG-gated image reconstruction comprise the technical corsage for reduction of pulsation artefacts in cardiac and other thoracic CT applications. In addition the development of time-optimised reconstruction algorithms for retrospective cardiac gating in 8- and 16 slice spiral CT scanners have enabled further improvements in temporal resolution. This overview describes the technique, its clinical indications and the merits of electrocardiographic assistance in MSCT of chest disorders.
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Affiliation(s)
- K Marten
- Department of Radiology, Klinikum rechts der Isar, Technical University, Munich, Germany.
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Kopp AF, Küttner A, Trabold T, Heuschmid M, Schröder S, Claussen CD. Multislice CT in cardiac and coronary angiography. Br J Radiol 2004; 77 Spec No 1:S87-97. [PMID: 15546845 DOI: 10.1259/bjr/30634988] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
In the last 2 years, mechanical multidetector-row CT (MDCT) systems with simultaneous acquisition of four slices and a half second scanner rotation time have become widely available. Data acquisition with these scanners allows for considerably faster coverage of the heart volume compared with single slice scanning. This increased scan speed can be used for retrospective gating together with 1 mm collimated slice widths and allows coverage of the entire cardiac volume in one breath-hold. First results from studies in correlation with intracoronary ultrasound suggest that MDCT technology not only offers the possibility to visualize intracoronary stenoses non-invasively, but also to differentiate plaque morphology. This is especially the case with the next generation of 16-row MDCT systems. An increased number of simultaneously acquired slices and submillimetre collimation for cardiac applications allows true isotropic scanning with high temporal resolution. Contrast-enhanced MDCT is a promising non-invasive technique for the detection, visualization and characterization of stenotic artery disease. It could act as a gatekeeper prior to cardiac catherization and finally replace conventional diagnostic modalities.
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Affiliation(s)
- A F Kopp
- Departments of Diagnostic Radiology and Internal Medicine, Division of Cardiology, Eberhard-Karls-University Tuebingen, Germany
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Lembcke A, Wiese TH, Schnorr J, Wagner S, Mews J, Kroencke TJ, Enzweiler CNH, Hamm B, Taupitz M. Image quality of noninvasive coronary angiography using multislice spiral computed tomography and electron-beam computed tomography: intraindividual comparison in an animal model. Invest Radiol 2004; 39:357-64. [PMID: 15167102 DOI: 10.1097/01.rli.0000123316.10765.6c] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Comparison of coronary artery visualization by multislice spiral CT (MSCT) and electron-beam CT (EBCT). MATERIALS AND METHODS Six minipigs underwent MSCT (collimation 4 x 1 mm, gantry rotation time 500 milliseconds, acquisition time per cardiac cycle 126 +/- 30 milliseconds) and EBCT (slice thickness 1.5 mm, acquisition time per scan 100 milliseconds). Visualized vessel length and contour sharpness was measured, contrast-to-noise ratios were calculated, and the frequency of motion artifacts were evaluated. RESULTS MSCT depicted significantly longer segments of the coronary tree than EBCT (length: 248.8 vs. 222.8 mm; P < 0.05), delineated the vessel contours more sharply (slope of density curves: 219.2 vs. 160.2 DeltaHU/mm; P < 0.05), and had a higher contrast-to-noise ratio (13.4 vs. 7.3; P < 0.05). The frequency of motion artifacts did not differ between both modalities (94.7% vs. 95.7% of visualized vessel length; P > 0.05). CONCLUSIONS Because its higher spatial resolution and lower image noise, MSCT seems to be superior to EBCT in the visualization of the coronary arteries. Despite different temporal resolutions motion artifacts seem to be similar with both modalities.
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Affiliation(s)
- Alexander Lembcke
- Department of Radiology, Charité Medical School, Humboldt-Universität zu Berlin, Schumannstrasse 20/21, 10098 Berlin, Germany.
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Deibler AR, Kuzo RS, Vöhringer M, Page EE, Safford RE, Patron JN, Lane GE, Morin RL, Gerber TC. Imaging of congenital coronary anomalies with multislice computed tomography. Mayo Clin Proc 2004; 79:1017-23. [PMID: 15301329 DOI: 10.4065/79.8.1017] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE To describe a single-center experience of using retrospectively gated multislice computed tomographic (MSCT) coronary angiography for imaging congenital coronary anomalies. PATIENTS AND METHODS We retrospectively reviewed the clinical information and imaging studies for 9 patients diagnosed as having congenital coronary anomalies on invasive, selective coronary angiography between February 2001 and October 2003 at the Mayo Clinic in Jacksonville, Fla. Two experienced observers classified by consensus the origin and proximal course of the abnormal coronary arteries as seen on MSCT. RESULTS In 1 patient, MSCT showed a normal but extremely anterior origin of the right coronary artery from the right aortic sinus of Valsalva. In the other 8 patients, the origin and course of 4 anomalous right coronary arteries, 2 anomalous left circumflex coronary arteries, and 2 single coronary arteries were recognized easily on MSCT. CONCLUSION Similar to electron beam computed tomography and magnetic resonance imaging, widely available MSCT can characterize the proximal course of congenitally abnormal coronary arteries and thus aid in clinical decision making for patients with such anomalies.
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Affiliation(s)
- Andrew R Deibler
- Department of Radiology, Mayo Clinic College of Medicine, Jacksonville, Fla 32224, USA
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Abstract
The socioeconomic importance of heart disease provides considerable motivation for development of radiologic tools for noninvasive imaging of the coronary arteries. Current computed tomographic (CT) techniques combine high speed and spatial resolution with sophisticated electrocardiographic synchronization and robustness of use. Application of these modalities for evaluation of coronary artery disease is a topic of active current research. Coronary artery calcium measurements with different CT techniques have been used for determining the risk of coronary events, but the exact role of this marker for cardiac risk stratification remains unclear pending results of population-based studies. Contrast material-enhanced CT coronary angiography has become an established clinical indication for some scenarios (eg, coronary artery anomalies, bypass patency, surgical planning). With current technology, the accuracy of CT coronary angiography for detection of coronary artery stenoses appears promising enough to warrant pursuit of this application, but sensitivity is still not high enough for routine diagnostic needs. The high negative predictive value of a normal CT coronary angiogram, however, may be useful for reliable exclusion of coronary artery stenosis. The cross-sectional nature of CT may allow noninvasive assessment of the coronary artery wall. Use of contrast-enhanced CT coronary angiography for detection, characterization, and quantification of atherosclerotic changes and total disease burden in coronary arteries as a potential tool for cardiac risk stratification is currently being investigated.
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Affiliation(s)
- U Joseph Schoepf
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
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Hastreiter D, Lewis D, Dubinsky TJ. Acute myocardial infarction demonstrated by multidetector CT scanning. Emerg Radiol 2004; 11:104-6. [PMID: 15278702 DOI: 10.1007/s10140-004-0364-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A 55-year-old man was brought to the emergency room complaining of left-sided chest pain. His electrocardiogram was indeterminate, and a multidetector computed tomogram (MDCT) was performed to exclude aortic dissection. The patient's aorta was normal, but an area of hypoperfusion was evident in the lateral ventricular myocardial wall. The ability to diagnose myocardial ischemia and infarcts on nongated MDCT is of particular clinical interest. As more imaging technology is devoted to imaging the heart, the greater expectations of radiologists' ability to diagnose cardiac disease in the emergency room will become.
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Kopp AF, Küttner A, Trabold T, Heuschmid M, Schröder S, Claussen CD. MDCT: cardiology indications. Eur Radiol 2004; 13 Suppl 5:M102-15. [PMID: 14989618 DOI: 10.1007/s00330-003-2138-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In the past 2 years mechanical multidetector-row CT (MDCT) systems with simultaneous acquisition of four slices and half-second scanner rotation have become widely available. Data acquisition with these scanners allows for considerably faster coverage of the heart volume compared with single-slice scanning. This increased scan speed can be used for retrospective gating together with 1-mm collimated slice widths and allows coverage of the entire cardiac volume in one breath hold. Initial results from studies in correlation with intracoronary ultrasound suggest that MDTC technology not only offers the possibility to visualize intracoronary stenoses non-invasively but also to differentiate plaque morphology. This is especially the case with the next generation of 16-row multidetector CT. An increased number of simultaneously acquired slices and sub-millimeter collimation for cardiac applications allows true isotropic scanning with high temporal resolution. Contrast-enhanced MDTC is a promising non-invasive technique for the detection, visualization, and characterization of stenotic artery disease. It could act as a gate keeper prior to cardiac catherization and finally replace conventional diagnostic modalities.
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Affiliation(s)
- Andreas F Kopp
- Department of Diagnostic Radiology, Eberhard Karls University Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany.
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Abstract
Contrast nephropathy after coronary angiography is associated with considerable morbidity and mortality. We discuss the incidence, definition, and pathologic mechanisms of contrast nephropathy; provide an overview of risk factors; highlight proven preventive interventions; clarify which interventions have shown no benefit; and discuss future possibilities. The prevention of contrast nephropathy is crucial for the care of patients undergoing coronary angiography and should be possible with an understanding of risk factors and proven management strategies.
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Affiliation(s)
- Apoor S Gami
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minn 55905, USA
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35
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Leta R, Carreras F, Alomar X, Monell J, García-Picart J, Augé JM, Salvador A, Pons-Lladó G. Coronariografía no invasiva mediante tomografía computarizada con 16 detectores: estudio comparativo con la angiografía coronaria invasiva. Rev Esp Cardiol 2004. [DOI: 10.1016/s0300-8932(04)77093-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Pannu HK, Flohr TG, Corl FM, Fishman EK. Current concepts in multi-detector row CT evaluation of the coronary arteries: principles, techniques, and anatomy. Radiographics 2003; 23 Spec No:S111-25. [PMID: 14557506 DOI: 10.1148/rg.23si035514] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cardiac imaging is becoming a practical application of mechanical computed tomography (CT) with the availability of four, eight, and 16 detector row scanners. The role of imaging is progressing from simple determination of the presence of arterial calcifications on nonenhanced scans to demonstration of vascular stenoses on coronary CT angiograms. Optimization of the imaging technique and knowledge of coronary artery anatomy are both important for the development of CT of the heart. Technical factors such as a slow heart rate, a short scanning time, subcentimeter spatial resolution, high temporal resolution, and reconstruction of multiple image data sets at various intervals in the cardiac cycle result in optimal visualization of the coronary arteries. Axial, thin-slab maximum intensity projection, and volume-rendered images are used to display the normal anatomy and anomalies of the coronary arteries. The challenges of CT angiography of the coronary arteries have been partially met and will likely be overcome with continued evolution of the technology.
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Affiliation(s)
- Harpreet K Pannu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Md, USA.
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Mahnken AH, Wildberger JE, Simon J, Koos R, Flohr TG, Schaller S, Günther RW. Detection of coronary calcifications: feasibility of dose reduction with a body weight-adapted examination protocol. AJR Am J Roentgenol 2003; 181:533-8. [PMID: 12876041 DOI: 10.2214/ajr.181.2.1810533] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to assess the applicability of individual body weight-adapted tube current time settings in multidetector CT for detection of coronary calcifications and to evaluate the effect of reducing the radiation dose on the coronary calcium score. SUBJECTS AND METHODS. One hundred patients underwent retrospectively ECG-gated MDCT for detection of coronary calcifications. First, fixed tube current time settings were used in 50 patients. Second, image noise corresponding to body weight-adapted tube current time settings was added to these images. Finally, body weight-adapted tube current time settings were applied to another 50 patients. For each patient group, the radiation dose was calculated. Coronary calcium scores were compared for the patient groups with the fixed tube current time settings with and without artificially added image noise. In all image series, image noise was assessed by a region-of-interest methodology. Image noise was analyzed using a regression analysis. RESULTS The effective radiation dose was reduced by 11.6% for men and 24.8% for women using the body weight-adapted tube current time settings. There were no statistically significant changes in the coronary calcium score after the addition of artificial image noise (p = 0.84). Adaptation of the tube current time settings did not lead to a relevant increase in image noise. The radiation doses for the plotted noise-to-body weight (slope, 0.081) and noise-to-body mass index (slope, 0.378) ratios for the standard protocol proved relatively high for patients of lower weight. An improved noise-to-body weight (slope, 0.054) and noise-to-body mass index (slope, 0.190) ratio was achieved by application of the body weight-adapted tube current time settings, resulting in nearly constant image noise related to body weight. CONCLUSION Individual body weight-adapted current time settings are applicable for coronary calcium scoring without a change of the coronary calcium score or relevant increase of the image noise.
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Affiliation(s)
- A H Mahnken
- Department of Diagnostic Radiology, University of Technology, Aachen, University Hospital, Pauwelsstr. 30, D-52074 Aachen, Germany
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MacNeill BD, Lowe HC, Takano M, Fuster V, Jang IK. Intravascular modalities for detection of vulnerable plaque: current status. Arterioscler Thromb Vasc Biol 2003; 23:1333-42. [PMID: 12805071 DOI: 10.1161/01.atv.0000080948.08888.bf] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Progress in the diagnosis, treatment, and prevention of atherosclerotic coronary artery disease is dependent on a greater understanding of the mechanisms of coronary plaque progression. Autopsy studies have characterized a subgroup of high-risk, or vulnerable, plaques that result in acute coronary syndromes or sudden cardiac death. These angiographically modest plaques share certain pathologic characteristics: a thin, fibrous cap, lipid-rich core, and macrophage activity. Diagnostic techniques for vulnerable-plaque detection, including serologic markers and noninvasive and invasive techniques, are needed. Recent advances in intravascular imaging have significantly improved the ability to detect high-risk, or vulnerable, plaque in vivo by using various features of plaque vulnerability as methods of identification. The characteristic anatomy of a thin, fibrous cap overlying a lipid pool has promoted high-resolution imaging, such as intravascular ultrasound, optical coherence tomography, and intracoronary magnetic resonance. The lipid-rich core is identifiable by angioscopically detected color changes on the plaque surface or by its unique absorption of energy, or "Raman shift," of its cholesterol core, driving coronary spectroscopy. Finally, temperature heterogeneity arising at foci of plaque inflammation has prompted the development of intracoronary thermography. In this review, we will discuss these techniques, their relative advantages and limitations, and their potential clinical application.
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Affiliation(s)
- Briain D MacNeill
- Cardiology Division, Massachusetts General Hospital and Harvard Medical School, Boston, Mass 02114, USA
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Brix G, Nagel HD, Stamm G, Veit R, Lechel U, Griebel J, Galanski M. Radiation exposure in multi-slice versus single-slice spiral CT: results of a nationwide survey. Eur Radiol 2003; 13:1979-91. [PMID: 12687286 DOI: 10.1007/s00330-003-1883-y] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2002] [Revised: 01/22/2003] [Accepted: 02/04/2003] [Indexed: 12/21/2022]
Abstract
Multi-slice (MS) technology increases the efficacy of CT procedures and offers new promising applications. The expanding use of MSCT, however, may result in an increase in both frequency of procedures and levels of patient exposure. It was, therefore, the aim of this study to gain an overview of MSCT examinations conducted in Germany in 2001. All MSCT facilities were requested to provide information about 14 standard examinations with respect to scan parameters and frequency. Based on this data, dosimetric quantities were estimated using an experimentally validated formalism. Results are compared with those of a previous survey for single-slice (SS) spiral CT scanners. According to the data provided for 39 dual- and 73 quad-slice systems, the average annual number of patients examined at MSCT is markedly higher than that examined at SSCT scanners (5500 vs 3500). The average effective dose to patients was changed from 7.4 mSv at single-slice to 5.5 mSv and 8.1 mSv at dual- and quad-slice scanners, respectively. There is a considerable potential for dose reduction at quad-slice systems by an optimisation of scan protocols and better education of the personnel. To avoid an increase in the collective effective dose from CT procedures, a clear medical justification is required in each case.
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Affiliation(s)
- G Brix
- Division of Medical Radiation Hygiene and Dosimetry, Institute of Radiation Hygiene, Federal Office for Radiation Protection, Neuherberg, Germany.
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40
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Rodenwaldt J. Multislice computed tomography of the coronary arteries. Eur Radiol 2003; 13:748-57. [PMID: 12664113 DOI: 10.1007/s00330-002-1800-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2002] [Accepted: 10/25/2002] [Indexed: 11/30/2022]
Abstract
Multislice spiral CT (MSCT) of the coronary arteries is developing rapidly as a noninvasive method for assessing coronary artery anatomy and for calculating various parameters of cardiac function. This article reviews the issues involved in MSCT coronary angiography and the methods used to overcome them. The current clinical applications for MSCT coronary angiography are summarized with reference to published clinical studies. The capabilities of CT are compared with those of MRI. Both modalities have a wide range of indications in the noninvasive diagnostic assessment of the heart and partly overlap in their clinical application.
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Affiliation(s)
- Jens Rodenwaldt
- Department of Radiology, Humboldt University, Schumannstrasse 20/21, 10117 Berlin, Germany.
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41
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Abstract
Despite a multitude of different medical and interventional strategies to treat coronary artery disease (CAD), the natural course of CAD is a relentless progression. The current gold-standard to assess the degree of stenosis is coronary angiography. In Germany alone, the total number of angiographic procedures rose by 45% from 1995 to 2000, while the fraction of interventional procedures remained almost constantly low at about 30% [Z. Kardiol. 90 (2001) 665]. Although coronary angiography has become a safe procedure with only a small risk associated, the inconvenience for the patient as well as the economic burden have fueled the quest to find an alternative, non-invasive method to visualize and assess coronary arteries. The following article will explore the application of computed tomography (CT) coronary angiography for detection of stenoses, and the issue of imaging of non-calcified and unstable plaques with MDCT.
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Neunteufl T, Maurer G. Noninvasive ultrasound techniques for the assessment of atherosclerosis in coronary artery disease. Circ J 2003; 67:177-86. [PMID: 12604862 DOI: 10.1253/circj.67.177] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Thomas Neunteufl
- Department of Cardiology, University of Vienna Medical School, Austria.
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43
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Affiliation(s)
- Richard L Morin
- Department of Radiology, Mayo Clinic, Jacksonville, Fla 32224, USA.
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44
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Gerber TC, O'Brien PC, Pastor K, Kuzo RS, Blackshear JL, Morin RL. Evaluation of reconstruction windows for multislice computed tomography in quantification of coronary calcium. Invest Radiol 2003; 38:108-18. [PMID: 12544074 DOI: 10.1097/00004424-200302000-00006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
RATIONALE AND OBJECTIVES To search for an optimum reconstruction window in retrospectively gated multislice computed tomography (MSCT) for quantification of coronary calcium. MATERIALS AND METHODS Coronary calcium quantified was examined as Agatston and volume scores by two experienced observers at 10 time points across the R-R interval of the electrocardiogram in 42 patients. A combination of statistical approaches was used to evaluate the distributions of minimum and maximum scores and of interobserver variability for both scoring methods across the cardiac cycle. RESULTS Based on the combination of evaluation approaches, 60% to 70% of the R-R interval appeared to be the optimum time point for obtaining maximum calcium scores with minimum interobserver variability. The optimum time point was more clearly defined for the Agatston score than for the volume score. CONCLUSION A reconstruction window beginning at 60% to 70% of the R-R interval seems to be most advantageous for retrospective gating of MSCT studies performed to quantify coronary calcium.
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Affiliation(s)
- Thomas C Gerber
- Department of Radiology, Mayo Clinic, Jacksonville, Florida 32224, USA.
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45
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Gerber TC, Kuzo RS, Lane GE, O'Brien PC, Karstaedt N, Morin RL, Safford RE, Blackshear JL, Pietan JH. Image quality in a standardized algorithm for minimally invasive coronary angiography with multislice spiral computed tomography. J Comput Assist Tomogr 2003; 27:62-9. [PMID: 12544245 DOI: 10.1097/00004728-200301000-00012] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE To report our experience with a standardized approach to pharmacologic heart rate control and image postprocessing for computed tomographic coronary angiography (CTCA) with multislice computed tomography (MSCT). METHOD Two experienced observers used transaxial tomograms and maximum-intensity projections to classify coronary segments (12 per patient, 135 consecutive patients) for degree of stenosis. One factor affecting image quality was identified for each segment that could not be assessed. RESULTS Nine patients (7%) were excluded for technical reasons. Of 1,512 segments from 126 patients, 1,086 (72%) were assessable (8.6 per patient). Of 300 segments from 25 patients who also had selective coronary angiography, CTCA was able to assess 211 (70%) and detected significant disease in 27 (82% sensitivity, 96% specificity, 73% positive predictive value, and 97% negative predictive value). Vessel caliber, heart rate, and Agatston score were associated with inability to assess 426 coronary segments (28%). CONCLUSION Heart rate and Agatston score are important predictors of the ability to assess proximal and midcoronary segments by CTCA with MSCT.
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Affiliation(s)
- Thomas C Gerber
- Division of Cardiovascular Diseases, Department of Radiology, Mayo Clinic, Jacksonville, FL 32224, USA.
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46
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McGrath BP. Imaging of arteries. Coron Artery Dis 2002; 13:399-403. [PMID: 12544713 DOI: 10.1097/00019501-200212000-00003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Barry P McGrath
- Department of Vascular Sciences and Medicine, Monash University, Dandenong Hospital, Australia.
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