101
|
Image Quality in a Low Radiation Exposure Protocol for Retrospectively ECG-Gated Coronary CT Angiography. AJR Am J Roentgenol 2009; 192:1045-50. [DOI: 10.2214/ajr.08.1025] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
102
|
Dikkers R, Greuter M, Kristanto W, van Ooijen P, Sijens P, Willems T, Oudkerk M. Assessment of image quality of 64-row Dual Source versus Single Source CT coronary angiography on heart rate: A phantom study. Eur J Radiol 2009; 70:61-8. [DOI: 10.1016/j.ejrad.2008.01.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 01/11/2008] [Accepted: 01/14/2008] [Indexed: 10/22/2022]
|
103
|
|
104
|
Arraiza M, Bastarrika G, Zudaire B, Pueyo J, Villanueva A. [Quantification of left ventricular function and mass in dual-source CT (DSCT).]. RADIOLOGIA 2009; 51:148-55. [PMID: 19286237 DOI: 10.1016/j.rx.2008.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 01/21/2008] [Indexed: 12/20/2022]
Abstract
OBJECTIVES To evaluate the interobserver agreement in quantifying left ventricular function and mass and to assess the accuracy of conventional manual contour tracing compared to semiautomatic segmentation analysis software. MATERIAL AND METHODS Twenty consecutive subjects who underwent cardiac DSCT with retrospective ECG-gating were included. Two different multiphase image reconstructions were done in 5% steps throughout the entire cardiac cycle (0-95% of the R-R interval) with effective slice thickness of 1mm in the axial plane and 8mm in the short-axis orientation. Left ventricular function and mass were calculated by two independent observers, tracing endocardial and epicardial borders manually and using a semiautomatic software tool (Circulation II, Siemens). Ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), cardiac output (CO), and myocardial mass were evaluated by two independent observers blind to each other's assessments. The interobserver agreement and the reliability of the different segmentation methods were calculated. The time required for manual contouring and semiautomatic contour tracing was also registered. RESULTS We found an excellent correlation (r>0.94; p<0.05) between the two independent observers for the quantification of left ventricular function and mass. Left ventricular functional parameters derived from semiautomatic contour software and conventional manual tracing method were not significantly different (p>0.05). The semiautomatic contour detection algorithm overestimated LV mass significantly compared with the manual contouring method (mean difference 29.45+/-1.64g; p<0.05). The time needed to calculate these parameters with the semiautomatic tool was significantly lower (248.85+/-99.8s) than with manual contouring (452.7+/-73.92s) (p<0.05). CONCLUSIONS Interobserver agreement for quantifying left ventricular function and mass using DSCT is excellent. Despite overestimating left ventricular mass, the semiautomatic software tool allows cardíac parameters to be quantified with the same reliability as the conventional manual method in half the time.
Collapse
Affiliation(s)
- M Arraiza
- Servicio de Radiología, Clínica Universidad de Navarra, Pamplona, España
| | | | | | | | | |
Collapse
|
105
|
|
106
|
Nucifora G, Schuijf JD, Tops LF, van Werkhoven JM, Kajander S, Jukema JW, Schreur JH, Heijenbrok MW, Trines SA, Gaemperli O, Turta O, Kaufmann PA, Knuuti J, Schalij MJ, Bax JJ. Prevalence of Coronary Artery Disease Assessed by Multislice Computed Tomography Coronary Angiography in Patients With Paroxysmal or Persistent Atrial Fibrillation. Circ Cardiovasc Imaging 2009; 2:100-6. [DOI: 10.1161/circimaging.108.795328] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Although atrial fibrillation (AF) has been linked to underlying coronary artery disease (CAD), data supporting this association have been based on ECG and clinical history for the definition of CAD rather than direct visualization of atherosclerosis.
Methods and Results—
The prevalence of CAD among patients with paroxysmal or persistent AF and without history of CAD was evaluated using multislice computed tomography. Multislice computed tomography was performed in 150 patients with AF (61�11 years, 67% males, 58% asymptomatic) with predominantly low (59%) or intermediate (25%) pretest likelihood of CAD. CAD was classified as obstructive (≥50% luminal narrowing) or not. A population of 148 patients without history of AF, similar to the AF group as to age, gender, symptomatic status, and pretest likelihood, served as a control group. Logistic regression analysis was applied to evaluate the relationship between demographic and clinical data and the presence of obstructive CAD. On the basis of multislice computed tomography, 18% of patients with AF were classified as having no CAD, whereas 41% showed nonobstructive CAD and the remaining 41% had obstructive CAD. Among patients without AF, 32% were classified as having no CAD, whereas 41% showed nonobstructive CAD and 27% had obstructive CAD (
P
=0.010 compared with patients with AF). At logistic regression analysis, age, male gender, and the presence of AF were significantly related to obstructive CAD.
Conclusion—
A higher prevalence of obstructive CAD was observed among patients with AF, confirming the hypothesis that AF could be a marker of advanced coronary atherosclerosis.
Collapse
Affiliation(s)
- Gaetano Nucifora
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Joanne D. Schuijf
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Laurens F. Tops
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Jacob M. van Werkhoven
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Sami Kajander
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - J. Wouter Jukema
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Joop H.M. Schreur
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Mark W. Heijenbrok
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Serge A. Trines
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Oliver Gaemperli
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Olli Turta
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Philipp A. Kaufmann
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Juhani Knuuti
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Martin J. Schalij
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| | - Jeroen J. Bax
- From the Department of Cardiology (G.N., J.D.S., L.F.T., J.M.v.W., J.W.J., S.A.T., M.J.S., J.J.B.), Leiden University Medical Center, Leiden, The Netherlands; Department of Cardiopulmonary Sciences (G.N.), University Hospital “Santa Maria della Misericordia,” Udine, Italy; Turku PET Center (S.K., O.T., J.K.), Turku University Central Hospital, Turku, Finland; The Interuniversity Cardiology Institute of The Netherlands (J.W.J.), Utrecht, The Netherlands; Departments of Cardiology and Radiology (J.H.M
| |
Collapse
|
107
|
Automatic selection of optimal systolic and diastolic reconstruction windows for dual-source CT coronary angiography. Eur Radiol 2009; 19:1645-52. [DOI: 10.1007/s00330-009-1329-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 01/08/2009] [Accepted: 01/21/2009] [Indexed: 10/21/2022]
|
108
|
Huda W, Nickoloff EL, Boone JM. Overview of patient dosimetry in diagnostic radiology in the USA for the past 50 years. Med Phys 2009; 35:5713-28. [PMID: 19175129 DOI: 10.1118/1.3013604] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This review covers the role of medical physics in addressing issues directly related to patient dosimetry in radiography, fluoroscopy, mammography, and CT. The sections on radiography and fluoroscopy radiation doses review the changes that have occurred during the last 50 to 60 years. A number of technological improvements have contributed to both a significant reduction in patient and staff radiation doses and improvements to the image quality during this period of time. There has been a transition from film-screen radiography with hand dip film processing to electronic digital imaging utilizing CR and DR. Similarly, fluoroscopy has progressed by directly viewing image intensifiers in darkened rooms to modern flat panel image receptor systems utilizing pulsed radiation, automated variable filtration, and digitally processed images. Mammography is one of the most highly optimized imaging procedures performed, because it is a repetitive screening procedure that results in annual radiation exposure. Mammography is also the only imaging procedure in the United States in which the radiation dose is regulated by the federal government. Consequently, many medical physicists have studied the dosimetry associated with screen-film and digital mammography. In this review, a brief history of mammography dose assessment by medical physicists is discussed. CT was introduced into clinical practice in the early 1970s, and has grown into one of the most important modalities available for diagnostic imaging. CT dose quantities and measurement techniques are described, and values of radiation dose for different types of scanner are presented. Organ and effective doses to adult patients are surveyed from the earliest single slice scanners, to the latest versions that include up to two x-ray tubes and can incorporate as many as 256 detector channels. An overview is provided of doses received by pediatric patients undergoing CT examinations, as well as methods, and results, of studies performed to assess the radiation absorbed by the conceptus of pregnant patients.
Collapse
Affiliation(s)
- Walter Huda
- Department of Radiology, Medical University of South Carolina, Charleston, South Carolina 29425-3230, USA.
| | | | | |
Collapse
|
109
|
Abstract
Imaging of the heart with computed tomography (CT) was already introduced in the 1980Is and has meanwhile entered clinical routine as a consequence of the rapid evolution of CT technology during the last decade. In this review article, we give an overview on the technology and clinical performance of different CT-scanner generations used for cardiac imaging, such as Electron Beam CT (EBCT), single-slice CT und multi-detector row CT (MDCT) with 4, 16 and 64 simultaneously acquired slices. We identify the limitations of current CT-scanners, indicate potential of improvement and discuss alternative system concepts such as CT with area detectors and dual source CT (DSCT).
Collapse
|
110
|
Influence of calcifications on diagnostic accuracy of coronary CT angiography using prospective ECG triggering. AJR Am J Roentgenol 2009; 191:1684-9. [PMID: 19020236 DOI: 10.2214/ajr.07.4040] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate the diagnostic accuracy of dual-source CT coronary angiography with prospective ECG triggering compared with catheter angiography and to determine the influence of vessel wall calcifications. SUBJECTS AND METHODS One hundred consecutive patients (42 women and 58 men; mean age, 65.8 +/- 6.5 years) with a sinus rhythm and heart rates < 70 beats per minute were included. Two independent, blinded readers classified coronary artery segments as being of diagnostic or nondiagnostic image quality and assessed each segment with diagnostic image quality for the presence of significant coronary stenoses. Nondiagnostic segments were excluded from analysis. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for all patients and for the subgroup of patients with a low or high calcium score (group A, median Agatston score < 316; group B, > or = 316). Catheter angiography was used as the reference standard. Effective radiation dose values were calculated. RESULTS In 89 of 100 patients (89%), 1,462 of 1,524 coronary segments (96%) were depicted with diagnostic image quality. The overall sensitivity, specificity, PPV, and NPV were 98%, 99%, 95%, and 100%, respectively. The rate of segments with nondiagnostic image quality was significantly higher (p < 0.001) in group B compared with group A. In group A, sensitivity, specificity, PPV, and NPV were 99%, 99%, 94%, and 100%, respectively, and in group B, 98%, 99%, 94%, and 99%, respectively, with no significant differences between the groups. The average effective radiation dose was 2.6 +/- 0.8 mSv (range, 1.2-4.4 mSv). CONCLUSION Dual-source CT coronary angiography with use of prospective ECG triggering performs accurately in the assessment of coronary artery disease at low radiation doses. Diagnostic accuracy remains high despite the presence of heavy calcifications but is associated with an increased rate of nondiagnostic segments.
Collapse
|
111
|
Improved noninvasive coronary angiography in morbidly obese patients with dual-source computed tomography. J Cardiovasc Comput Tomogr 2009; 3:35-42. [DOI: 10.1016/j.jcct.2008.11.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 11/19/2008] [Accepted: 11/25/2008] [Indexed: 11/24/2022]
|
112
|
Sayyed SH, Cassidy MM, Hadi MA. Use of multidetector computed tomography for evaluation of global and regional left ventricular function. J Cardiovasc Comput Tomogr 2009; 3:S23-34. [DOI: 10.1016/j.jcct.2008.10.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 10/17/2008] [Accepted: 10/25/2008] [Indexed: 10/21/2022]
|
113
|
McCollough CH, Primak AN, Braun N, Kofler J, Yu L, Christner J. Strategies for reducing radiation dose in CT. Radiol Clin North Am 2009; 47:27-40. [PMID: 19195532 PMCID: PMC2743386 DOI: 10.1016/j.rcl.2008.10.006] [Citation(s) in RCA: 518] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In recent years, the media has focused on the potential danger of radiation exposure from CT, even though the potential benefit of a medically indicated CT far outweighs the potential risks. This attention has reminded the radiology community that doses must be as low as reasonably achievable (ALARA) while maintaining diagnostic image quality. To satisfy the ALARA principle, the dose reduction strategies described in this article must be well understood and properly used. The use of CT must also be justified for the specific diagnostic task.
Collapse
Affiliation(s)
- Cynthia H. McCollough
- Associate Professor of Radiologic Physics, Department of Radiology, Mayo Clinic, Rochester, Minnesota
| | - Andrew N. Primak
- Research Associate, Department of Radiology, Mayo Clinic, Rochester, Minnesota
| | - Natalie Braun
- Research Fellow, Department of Radiology, Mayo Clinic, Rochester, Minnesota
| | - James Kofler
- Assistant Professor of Radiologic Physics, Department of Radiology, Mayo Clinic, Rochester, Minnesota
| | - Lifeng Yu
- Assistant Professor of Radiologic Physics, Department of Radiology, Mayo Clinic, Rochester, Minnesota
| | - Jodie Christner
- Research Fellow, Department of Radiology, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
114
|
Radiation dose values for various coronary calcium scoring protocols in dual-source CT. Int J Cardiovasc Imaging 2008; 25:443-51. [DOI: 10.1007/s10554-008-9397-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2008] [Accepted: 11/28/2008] [Indexed: 10/21/2022]
|
115
|
|
116
|
Thoracic applications of dual-source CT technology. Eur J Radiol 2008; 68:375-84. [DOI: 10.1016/j.ejrad.2008.08.016] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Accepted: 08/29/2008] [Indexed: 11/17/2022]
|
117
|
Kajander S, Ukkonen H, Sipilä H, Teräs M, Knuuti J. Low radiation dose imaging of myocardial perfusion and coronary angiography with a hybrid PET/CT scanner. Clin Physiol Funct Imaging 2008; 29:81-8. [PMID: 19016814 PMCID: PMC2701563 DOI: 10.1111/j.1475-097x.2008.00838.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Objectives: To test the image quality and feasibility of a sequential low radiation dose protocol for hybrid cardiac PET/CT angiography (CTA). Background: Multidetector computed tomography (MDCT) is a non-invasive method for coronary angiography. The negative predictive value of MDCT is high but perfusion imaging has a role in detecting functional significance of coronary lesions. This has encouraged combining these techniques. However, radiation dose is of concern. We report our first experiences with a low dose sequential CTA mode applicable to hybrid imaging. Methods: In the first phase, 10 consecutive cardiac MDCT angiographies were performed with spiral acquisition and compared in terms of image quality and dose with the following 10 patients performed with a new sequential mode. In the second phase, feasibility and radiation dose of a combined 15O-water rest-stress PET perfusion/sequential CTA protocol were assessed in another group of 61 consecutive patients. Results: Mean effective radiation dose was 60% lower in the sequential group than in the spiral group (19·3 versus 7·6 mSv, P<0·001). In the second phase, the new sequential hybrid protocol proved possible in 87% of the patients given the preconditions determined by the manufacturer. Mean effective dose of the CT acquisition was 7·6 mSv and total dose from the PET/CTA hybrid study 9·5 mSv. Conclusion: Low dose PET/CT allows cardiac hybrid studies with <10 mSv. The protocol can be applied to almost nine out of 10 patients with CT image quality comparable to spiral acquisition.
Collapse
|
118
|
Stolzmann P, Frauenfelder T, Pfammatter T, Peter N, Scheffel H, Lachat M, Schmidt B, Marincek B, Alkadhi H, Schertler T. Endoleaks after Endovascular Abdominal Aortic Aneurysm Repair: Detection with Dual-Energy Dual-Source CT. Radiology 2008; 249:682-91. [DOI: 10.1148/radiol.2483080193] [Citation(s) in RCA: 182] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
119
|
Niinuma H, George RT, Arbab-Zadeh A, Lima JA, Henrikson CA. Imaging of pulmonary veins during catheter ablation for atrial fibrillation: the role of multi-slice computed tomography. Europace 2008; 10 Suppl 3:iii14-21. [DOI: 10.1093/europace/eun230] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
120
|
Pannu HK, Johnson PT, Fishman EK. 64 Slice multi-detector row cardiac CT. Emerg Radiol 2008; 16:1-10. [PMID: 18941811 DOI: 10.1007/s10140-008-0760-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Accepted: 08/04/2008] [Indexed: 10/21/2022]
|
121
|
Tan JSP, Tan KL, Lee JCL, Wan CM, Leong JL, Chan LL. Comparison of eye lens dose on neuroimaging protocols between 16- and 64-section multidetector CT: achieving the lowest possible dose. AJNR Am J Neuroradiol 2008; 30:373-7. [PMID: 18854441 DOI: 10.3174/ajnr.a1327] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE To our knowledge, there has been no study that compares the radiation dose delivered to the eye lens by 16- and 64-section multidetector CT (MDCT) for standard clinical neuroimaging protocols. Our aim was to assess radiation-dose differences between 16- and 64-section MDCT from the same manufacturer, by using near-identical neuroimaging protocols. MATERIALS AND METHODS Three cadaveric heads were scanned on 16- and 64-section MDCT by using standard neuroimaging CT protocols. Eye lens dose was measured by using thermoluminescent dosimeters (TLD), and each scanning was repeated to reduce random error. The dose-length product, volume CT dose index (CTDI(vol)), and TLD readings for each imaging protocol were averaged and compared between scanners and protocols, by using the paired Student t test. Statistical significance was defined at P < .05. RESULTS The radiation dose delivered and eye lens doses were lower by 28.1%-45.7% (P < .000) on the 64-section MDCT for near-identical imaging protocols. On the 16-section MDCT, lens dose reduction was greatest (81.1%) on a tilted axial mode, compared with a nontilted helical mode for CT brain scans. Among the protocols studied, CT of the temporal bone delivered the greatest radiation dose to the eye lens. CONCLUSIONS Eye lens radiation doses delivered by the 64-section MDCT are significantly lower, partly due to improvements in automatic tube current modulation technology. However, where applicable, protection of the eyes from the radiation beam by either repositioning the head or tilting the gantry remains the best way to reduce eye lens dose.
Collapse
Affiliation(s)
- J S P Tan
- Department of Diagnostic Radiology, Singapore General Hospital, Singapore.
| | | | | | | | | | | |
Collapse
|
122
|
Halliburton SS, Sola S, Kuzmiak SA, Obuchowski NA, Desai M, Flamm SD, Schoenhagen P. Effect of dual-source cardiac computed tomography on patient radiation dose in a clinical setting: comparison to single-source imaging. J Cardiovasc Comput Tomogr 2008; 2:392-400. [PMID: 19083984 DOI: 10.1016/j.jcct.2008.09.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 09/17/2008] [Accepted: 09/20/2008] [Indexed: 11/19/2022]
Abstract
BACKGROUND Dual-source computed tomography (DSCT) was introduced with significant hardware and software changes compared with single-source CT (SSCT), resulting in improved temporal resolution (83 ms) and the potential for improved image quality. The effect of these changes on radiation dose requirements for coronary CT angiography in clinical practice has not been investigated. OBJECTIVE We evaluated patient radiation dose and image quality of electrocardiogram (ECG)-gated helical techniques, using DSCT compared with SSCT for clinical imaging of the coronary arteries. METHODS DSCT data from 160 patients were evaluated; 82 patients (DSCT group 1) were imaged with early software, and 78 patients (DSCT group 2) were imaged with a later software version. Patients imaged with SSCT (n = 124) were the control group. Effective radiation dose values were estimated for all patients. Image noise was measured, and image quality was evaluated on a 5-point scale. RESULTS Effective dose values for DSCT group 2 (11.7 +/- 4.0 mSv) were not different from those for SSCT group (10.9 +/- 2.9 mSv); the highest doses, 13.2 +/- 3.2 mSv, were recorded for DSCT group 1 (P < 0.001). A decrease in image noise was observed for DSCT compared with SSCT (P <or= 0.001) as was an increase in image quality (P < 0.01). With optimized DSCT imaging, lower dose values were associated with (1) shorter scan range, (2) lower maximum tube current, and (3) lower fraction of R-R interval receiving maximum tube current. CONCLUSION ECG-gated helical DSCT can provide images of the coronary arteries with improved image quality and decreased noise without an increase in radiation dose compared with SSCT in clinical patient groups.
Collapse
Affiliation(s)
- Sandra S Halliburton
- Cardiovascular Imaging Laboratory, Imaging Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| | | | | | | | | | | | | |
Collapse
|
123
|
Stolzmann P, Leschka S, Scheffel H, Krauss T, Desbiolles L, Plass A, Genoni M, Flohr TG, Wildermuth S, Marincek B, Alkadhi H. Dual-Source CT in Step-and-Shoot Mode: Noninvasive Coronary Angiography with Low Radiation Dose1. Radiology 2008; 249:71-80. [PMID: 18796669 DOI: 10.1148/radiol.2483072032] [Citation(s) in RCA: 206] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Paul Stolzmann
- Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich, Switzerland
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
124
|
Gleeson TG, Mwangi I, Horgan SJ, Cradock A, Fitzpatrick P, Murray JG. Steady-state free-precession (SSFP) cine MRI in distinguishing normal and bicuspid aortic valves. J Magn Reson Imaging 2008; 28:873-878. [DOI: 10.1002/jmri.21547] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
|
125
|
Leschka S, Alkadhi H, Stolzmann P, Schmid FT, Leschka SC, Scheffel H, Stinn B, Flohr TG, Marincek B, Wildermuth S. Mono- Versus Bisegment Reconstruction Algorithms for Dual-Source Computed Tomography Coronary Angiography. Invest Radiol 2008; 43:703-11. [DOI: 10.1097/rli.0b013e31817de87b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
126
|
Weustink AC, Mollet NR, Pugliese F, Meijboom WB, Nieman K, Heijenbrok-Kal MH, Flohr TG, Neefjes LAE, Cademartiri F, de Feyter PJ, Krestin GP. Optimal electrocardiographic pulsing windows and heart rate: effect on image quality and radiation exposure at dual-source coronary CT angiography. Radiology 2008; 248:792-8. [PMID: 18710975 DOI: 10.1148/radiol.2483072098] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To determine the optimal width and timing of the electrocardiographic (ECG) pulsing window within the cardiac cycle in relation to heart rate (HR), image quality, and radiation exposure in patients who are suspected of having coronary artery disease. MATERIALS AND METHODS The institutional review board approved the study, and all patients gave informed consent. Dual-source computed tomography (CT) was performed in 301 patients (mean HR, 70.1 beats per minute +/- 13.3 [standard deviation]; range, 43-112 beats per minute) by using a wide ECG pulsing window (25%-70% of the R-R interval). Data sets were reconstructed in 5% steps from 20%-75% of R-R interval. Image quality was assessed by two observers on a per-segment level and was classified as good or impaired. High-quality data sets were those in which each segment was of good quality. The width and timing of the image reconstruction window was calculated. On the basis of these findings, an optimal HR-dependent ECG pulsing protocol was designed, and the potential dose-saving effect on effective dose (in millisieverts) was calculated. RESULTS At low HR (< or = 65 beats per minute), high-quality data sets were obtained during end diastole (ED); at high HR (> or = 80 beats per minute), they were obtained during end systole (ES); and at intermediate HR (66-79 beats per minute), they were obtained during both ES and ED. Optimal ECG pulsing windows for low, intermediate, and high HR were at 60%-76%, 30%-77%, and 31%-47% of the R-R interval, respectively, and with these levels, the effective dose was decreased at low HR from 18.7 to 6.8 mSv, at intermediate HR from 14.7 to 13.4 mSv, and at high HR from 11.3 to 4.2 mSv. CONCLUSION With optimal ECG pulsing, radiation exposure to patients, particularly those with low or high HR, can be reduced with preservation of image quality.
Collapse
Affiliation(s)
- Annick C Weustink
- Department of Radiology, Erasmus Medical Center, PO Box 2040, Room Hs 218, 3000 CA Rotterdam, The Netherlands
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
127
|
Gutstein A, Dey D, Cheng V, Wolak A, Gransar H, Suzuki Y, Friedman J, Thomson LE, Hayes S, Pimentel R, Paz W, Slomka P, Le Meunier L, Germano G, Berman DS. Algorithm for radiation dose reduction with helical dual source coronary computed tomography angiography in clinical practice. J Cardiovasc Comput Tomogr 2008; 2:311-22. [DOI: 10.1016/j.jcct.2008.07.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 07/24/2008] [Accepted: 02/27/2008] [Indexed: 11/16/2022]
|
128
|
Truong QA, Hoffmann U, Singh JP. Potential uses of computed tomography for management of heart failure patients with dyssynchrony. Crit Pathw Cardiol 2008; 7:185-90. [PMID: 18791407 PMCID: PMC3733254 DOI: 10.1097/hpc.0b013e318178eaa5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Abstract
Cardiac resynchronization therapy has become an integral part in the step-care approach to manage patients with heart failure. Cardiac imaging remains central to appropriate patient selection and optimal left ventricular lead placement, both of which are important determinants of response to cardiac resynchronization therapy. One of the biggest limitations with current imaging modalities is the inability of a single technique to address each, the anatomic (venous anatomy), mechanical (dyssynchrony), and structural (extent of scar location) issues accompanying cardiomyopathy. We present here the potential concept of using cardiac computed tomography as a single modality to acquire functional and anatomic information, and also to show the possibility of integrating this with real time fluoroscopy.
Collapse
Affiliation(s)
- Quynh A. Truong
- Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Udo Hoffmann
- Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Jagmeet P. Singh
- Cardiac Arrhythmia Service, Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| |
Collapse
|
129
|
Zhang LJ, Wang YZ, Huang W, Chen P, Zhou CS, Lu GM. Anatomical investigation of the sinus node artery using dual-source computed tomography. Circ J 2008; 72:1615-20. [PMID: 18728333 DOI: 10.1253/circj.cj-08-0149] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Few investigators have studied the anatomy of the sinus node artery (SNA) using noninvasive imaging modalities, so the objective of this study was to visualize the in-vivo 3-dimensional anatomical relations of the SNA using dual-source computed tomography (DSCT). METHODS AND RESULTS In the 101 patients included in this study, the visualization rate, anatomical type and diameter of the SNA, the distance between the orifice and coronary artery, and the terminal type of SNA were recorded. The visualization rate was 95.2% (96/101). Of 96 patients, 106 SNAs were detected among which 51 (48.1%, 51/106) originated from the right coronary artery, 52 (49.1%, 52/106) from the left circumflex artery, and 3 (2.7%, 3/106) from other branches. There were 3 types of SNA: right (n = 52), left (n = 45), and posterior (n = 9). The distance between the orifice of the right SNA and the right coronary sinus was 14.2+/-15.2 mm, for the left SNA it was 5.5+/-3.5 mm, and for the posterior SNA, 33.7+/-12.8 mm. The average diameter was 1.27+/-0.29 mm. The SNA approached the nodal tissue by 1 of 3 routes: retrocaval (51.5%), precaval (25.2%), or pericaval (22.3%). CONCLUSION The SNA can be visualized in vivo using DSCT, which is important for preoperative knowledge of its origin, course, termination, and anatomical type.
Collapse
Affiliation(s)
- Long Jiang Zhang
- Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, Jiangsu Province, China
| | | | | | | | | | | |
Collapse
|
130
|
Visualization of anomalous coronary arteries on dual-source computed tomography. Eur Radiol 2008; 18:2425-32. [DOI: 10.1007/s00330-008-1110-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Revised: 02/07/2008] [Accepted: 03/16/2008] [Indexed: 11/25/2022]
|
131
|
Ketelsen D, Luetkhoff MH, Thomas C, Werner M, Buchgeister M, Tsiflikas I, Reimann A, Burgstahler C, Kopp AF, Claussen CD, Heuschmid M. Estimation of the radiation exposure of a chest pain protocol with ECG-gating in dual-source computed tomography. Eur Radiol 2008; 19:37-41. [DOI: 10.1007/s00330-008-1109-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2008] [Accepted: 06/22/2008] [Indexed: 10/21/2022]
|
132
|
|
133
|
Catalano C, Francone M, Ascarelli A, Mangia M, Iacucci I, Passariello R. Optimizing radiation dose and image quality. Eur Radiol 2008; 17 Suppl 6:F26-32. [PMID: 18376454 DOI: 10.1007/s10406-007-0225-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Radiation exposure is a critical issue in multidetector CT (MDCT) particularly since fast MDCT scanners have become widely available, and the method has been proposed as a noninvasive diagnostic tool for an increasing number of clinical applications. Additional features of MDCT imaging affecting individual dose are related to the inappropriate use of scanners caused by practices such as scanning beyond the area of interest or acquiring unnecessary multiphase image sets. In order to reduce individual exposure and in accordance with the ALARA principle, several strategies have been implemented over the last few years which are based on X-ray emission or optimization of scanning parameters (i.e. mAs, kV, pitch, collimation) or which take account of the individual patient's characteristics (automatic exposure control systems and ECG-pulsing techniques for ECG-gated acquisitions). These strategies allow optimization of image quality while keeping individual exposure at the lowest level. We review here these different strategies taking into account the relationship between image noise and different scanning parameters. Data from the literature are discussed, and current technological developments are considered, including initial results of dual source and SnapShot pulse technologies which have been shown to result in a significant dose reduction in ECG-gated cardiac acquisitions without compromising image quality.
Collapse
Affiliation(s)
- Carlo Catalano
- Department of Radiological Sciences, University of Rome La Sapienza, Rome, Italy.
| | | | | | | | | | | |
Collapse
|
134
|
McCollough CH, Schmidt B, Yu L, Primak A, Ulzheimer S, Bruder H, Flohr TG. Measurement of temporal resolution in dual source CT. Med Phys 2008; 35:764-8. [PMID: 18383698 DOI: 10.1118/1.2826559] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
This work assesses the temporal resolution of dual-source computed tomography (CT) in a visually intuitive manner. Exploiting the principles of ring artifact creation, a phantom containing a highly attenuating delta function signal (a wire) was rotated at the same speed as the gantry, creating a partial ring artifact where the angular extent of the artifact provides a direct indication of the temporal resolution. A demonstration of the effect of the evaluated 165 and 83 ms nominal temporal resolutions on motion artifacts in cardiac CT is provided using patient data.
Collapse
Affiliation(s)
- Cynthia H McCollough
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
| | | | | | | | | | | | | |
Collapse
|
135
|
Papillary fibroelastoma of the aortic valve and coronary artery disease visualized by 64-slice CT. ACTA ACUST UNITED AC 2008; 5:350-3. [DOI: 10.1038/ncpcardio1212] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2007] [Accepted: 02/08/2008] [Indexed: 11/08/2022]
|
136
|
Leschka S, Stolzmann P, Schmid FT, Scheffel H, Stinn B, Marincek B, Alkadhi H, Wildermuth S. Low kilovoltage cardiac dual-source CT: attenuation, noise, and radiation dose. Eur Radiol 2008; 18:1809-17. [PMID: 18392829 DOI: 10.1007/s00330-008-0966-1] [Citation(s) in RCA: 218] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Revised: 02/04/2008] [Accepted: 03/05/2008] [Indexed: 12/20/2022]
Abstract
The purpose of this study was to investigate the effect of low kilovoltage dual-source computed tomography coronary angiography (CTCA) on qualitative and quantitative image quality parameters and radiation dose. Dual-source CTCA with retrospective ECG gating was performed in 80 consecutive patients of normal weight. Forty were examined with a standard protocol (120 kV/330mAs), 20 were examined at 100 kV/330mAs, and 20 at 100 kV/220mAs. Two blinded observers independently assessed image quality of each coronary segment and measured the image parameters noise, attenuation, and contrast-to-noise ratio (CNR). The effective radiation dose was calculated using CT dose volume index and the dose-length product. Diagnostic image quality was obtained in 99% of all coronary segments (1,127/1,140) without significant differences among the protocols. Image noise, attenuation, and CNR were significantly higher for 100 kV/330mAs (26 +/- 3 HU, 549 +/- 62 HU, 25.5 +/- 3.2; each P < 0.01) and 100 kV/220mAs (27 +/- 2 HU, 560 +/- 43 HU, 25.0 +/- 2.2; each P < 0.01) when compared to the 120-kV protocol (21 +/- 2 HU, 317 +/- 28 HU, 20.6 +/- 1.7). There was no significant difference between the two 100-kV protocols. Estimated effective radiation dose of the 120-kV protocol (8.9 +/- 1.2 mSv) was significantly higher than the 100 kV/330mAs (6.7 +/- 0.8 mSv, P < 0.01) or 100 kV/220mAs (4.4 +/- 0.6 mSv, P < 0.001) protocols. Dual-source CTCA with 100 kV is feasible in patients of normal weight, results in a diagnostic image quality with a higher CNR, and at the same time significantly reduces the radiation dose.
Collapse
Affiliation(s)
- Sebastian Leschka
- Institute of Radiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
137
|
Rybicki FJ, Otero HJ, Steigner ML, Vorobiof G, Nallamshetty L, Mitsouras D, Ersoy H, Mather RT, Judy PF, Cai T, Coyner K, Schultz K, Whitmore AG, Di Carli MF. Initial evaluation of coronary images from 320-detector row computed tomography. Int J Cardiovasc Imaging 2008; 24:535-46. [PMID: 18368512 DOI: 10.1007/s10554-008-9308-2] [Citation(s) in RCA: 385] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Accepted: 03/19/2008] [Indexed: 12/16/2022]
Abstract
PURPOSE To evaluate image quality and contrast opacification from coronary images acquired from 320-detector row computed tomography (CT). Patient dose is estimated for prospective and retrospective ECG-gating; initial correlation between 320-slice CT and coronary catheterization is illustrated. METHODS Retrospective image evaluation from forty consecutive patients included subjective assessment of image quality and contrast opacification (80 ml iopamidol 370 mg I/ml followed by 40 ml saline). Region of interest opacification measurements at the ostium and at 2.5 mm diameter were used to determine the gradient of contrast opacification (defined as the proximal minus distal HU measurements) in coronary arteries imaged in a single heartbeat. Estimated effective dose was compared for prospective versus retrospective ECG-gating, two body mass index categories (30 kg/m(2) cutoff), and single versus two heartbeat acquisition. When available, CT findings were correlated with those from coronary catheterization. RESULTS Over 89% of arterial segments (15 segment model) had excellent image quality. The most common reason for image degradation was cardiac motion. One segment in one patient was considered unevaluable. Contrast opacification was almost universally considered excellent. The mean Hounsfield units (HU) was greater than 350; the coronary contrast opacification gradient was 30-50 HU. Patient doses were greater for retrospective ECG-gating, larger patients, and those imaged with two heartbeats. For the most common (n=25) protocol (120 kV, 400 mA, prospective ECG-gating, 60-100% phase window, 16 cm craniocaudal coverage, single heartbeat), the mean dose was 6.8+/-1.4 mSv. All CT findings were confirmed in the four patients who underwent coronary catheterization. CONCLUSION Initial 320-detector row coronary CT images have consistently excellent quality and iodinated contrast opacification. These patients were scanned with conservative protocols with respect to iodine load, prospective ECG-gating phase window, and craniocaudal coverage. Future work will focus on lowering contrast and radiation dose while maintaining image quality.
Collapse
Affiliation(s)
- Frank J Rybicki
- Noninvasive Cardiovascular Imaging, Brigham and Women's Hospital, Boston, MA 02115, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
138
|
Abstract
Numerous imaging techniques permit evaluation of regional pulmonary function. Contrast-enhanced CT methods now allow assessment of vasculature and lung perfusion. Techniques using spirometric controlled multi-detector row CT allow for quantification of presence and distribution of parenchymal and airway pathology; xenon gas can be employed to assess regional ventilation of the lungs, and rapid bolus injections of iodinated contrast agent can provide a quantitative measure of regional parenchymal perfusion. Advances in MRI of the lung include gadolinium-enhanced perfusion imaging and hyperpolarized gas imaging, which allow functional assessment, including ventilation/perfusion, microscopic air space measurements, and gas flow and transport dynamics.
Collapse
Affiliation(s)
- Edwin J R van Beek
- Department of Radiology, Carver College of Medicine, University of Iowa, C-751 GH, 200 Hawkins Drive, Iowa City, IA 52242-1077, USA.
| | | |
Collapse
|
139
|
Dual-source cardiac computed tomography: image quality and dose considerations. Eur Radiol 2008; 18:1188-98. [DOI: 10.1007/s00330-008-0883-3] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 12/10/2007] [Accepted: 01/11/2008] [Indexed: 12/21/2022]
|
140
|
Bastarrika G, Arraiza M, Pueyo JC, Herraiz MJ, Zudaire B, Villanueva A. Quantification of left ventricular function and mass in cardiac Dual-Source CT (DSCT) exams: comparison of manual and semiautomatic segmentation algorithms. Eur Radiol 2008; 18:939-46. [PMID: 18292999 DOI: 10.1007/s00330-007-0849-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 11/02/2007] [Accepted: 12/28/2007] [Indexed: 12/20/2022]
Abstract
The purpose of our study was to evaluate reliability of left ventricular (LV) function and mass quantification in cardiac DSCT exams comparing manual contour tracing and a region-growing-based semiautomatic segmentation analysis software. Thirty-three consecutive patients who underwent cardiac DSCT exams were included. Axial 1-mm slices were used for the semiautomated technique, and short-axis 8-mm slice thickness multiphase image reconstructions were the basis for manual contour tracing. Left ventricular volumes, ejection fraction and myocardial mass were assessed by both segmentation methods. Length of time needed for both techniques was also recorded. Left ventricular functional parameters derived from semiautomatic contour detection algorithm were not statistically different from manual tracing and showed an excellent correlation (p<0.001). The semiautomatic contour detection algorithm overestimated LV mass (180.30+/-44.74 g) compared with manual contour tracing (156.07+/-46.29 g) (p<0.001). This software allowed a significant reduction of the time needed for global LV assessment (mean 174.16+/-71.53 s, p<0.001). Objective quantification of LV function using the evaluated region-growing-based semiautomatic segmentation analysis software is feasible, accurate, reliable and time-effective. However, further improvements are needed to equal results achieved by manual contour tracing, especially with regard to LV mass quantification.
Collapse
Affiliation(s)
- Gorka Bastarrika
- Department of Radiology, Clínica Universitaria. Universidad de Navarra, Avda. Pío XII, 36, 31008 Pamplona, Spain.
| | | | | | | | | | | |
Collapse
|
141
|
Image quality and artifacts in coronary CT angiography with dual-source CT: initial clinical experience. J Cardiovasc Comput Tomogr 2008; 2:105-14. [PMID: 19083930 DOI: 10.1016/j.jcct.2007.12.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2007] [Revised: 12/18/2007] [Accepted: 12/21/2007] [Indexed: 11/23/2022]
Abstract
INTRODUCTION We aimed to characterize artifacts observed in a routine clinical coronary CT angiography (CCTA) performed by a dual-source CT (DSCT) scanner (Definition; Siemens Medical Solutions). METHODS Studies of 167 consecutive patients referred for CCTA, performed after beta-blockade (if not contraindicated), were prospectively analyzed for artifacts with a predefined visual approach. American Heart Association coronary segments (n = 2589) were assessed in 40%-80% R-R interval phases by 2 experts for stenosis, plaque presence or composition, and presence or type of artifacts. Each segment was considered evaluable when image quality was diagnostic in at least one cardiac phase. Artifacts included motion (cardiac, respiratory, patient), phase misregistration because of varying heart beats, calcified plaque blooming or beam hardening, metal beam hardening, large patient size, and contrast timing error. RESULTS Maximum HR (HR) during CCTA ranged from 45 to 120 beats/min (66.4 +/- 14.8 beats/min). Artifacts of some type were observed in 69 (41.3%) of 167 studies. Calcified plaque was the most common source of artifacts (14.4%), followed by misregistration (13.8%). Only 25 (1%) of 2589 coronary segments, in 6 (4%) of 167 patients were unevaluable, primarily because of calcified plaque blooming (coronary calcium score [CCS], 1112 +/- 1255]. Artifacts were associated with CCS (P = 0.002), change in HR (P = 0.01), age (P = 0.03), and body mass index (P = 0.048). The optimal phase for evaluation of all coronary arteries was 70% (mid-diastole), with a shift toward the systolic phases for HR > 70 beats/min. CONCLUSION CCTA artifacts with DSCT were related primarily to calcified plaque and cardiac phase misregistration. When correctly recognized, the artifacts did not have a serious effect on the final interpretation.
Collapse
|
142
|
Earls JP, Berman EL, Urban BA, Curry CA, Lane JL, Jennings RS, McCulloch CC, Hsieh J, Londt JH. Prospectively gated transverse coronary CT angiography versus retrospectively gated helical technique: improved image quality and reduced radiation dose. Radiology 2008; 246:742-53. [PMID: 18195386 DOI: 10.1148/radiol.2463070989] [Citation(s) in RCA: 402] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE To retrospectively compare image quality, radiation dose, and blood vessel assessability for coronary artery computed tomographic (CT) angiograms obtained with a prospectively gated transverse (PGT) CT technique and a retrospectively gated helical (RGH) CT technique. MATERIALS AND METHODS This HIPAA-compliant study received a waiver for approval from the institutional review board, including one for informed consent. Coronary CT angiograms obtained with 64-detector row CT were retrospectively evaluated in 203 clinical patients. A routine RGH technique was evaluated in 82 consecutive patients (44 males, 38 females; mean age, 55.6 years). The PGT technique was then evaluated in 121 additional patients (71 males, 50 females; mean age, 56.7 years). All images were evaluated for image quality, estimated radiation dose, and coronary artery segment assessability. Differences in image quality score were evaluated by using a proportional odds logistic regression model, with main effects for three readers, two techniques, and four arteries. RESULTS The mean effective dose for the group with the PGT technique was 2.8 mSv; this represents an 83% reduction as compared with that for the group with the RGH technique (mean, 18.4 mSv; P < .001). The image quality score for each of the arteries, as well as the overall combined score, was significantly greater for images obtained with PGT technique than for images obtained with RGH technique. The combined mean image quality score was 4.791 for images obtained with PGT technique versus 4.514 for images obtained with RGH technique (proportional odds model odds ratio, 2.8; 95% confidence interval: 1.7, 4.8). The percentage of assessable coronary artery segments was 98.6% (1196 of 1213) for images obtained with PGT technique versus 97.9% (1741 of 1778) for images obtained with RGH technique (P = .83). CONCLUSION PGT coronary CT angiography offers improved image quality and substantially reduced effective radiation dose compared with traditional RGH coronary CT angiography.
Collapse
Affiliation(s)
- James P Earls
- Fairfax Radiological Consultants P.C., 2722 Merrilee Dr, Suite 230, Fairfax, VA 22031, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
143
|
Optimal Systolic and Diastolic Reconstruction Windows for Coronary CT Angiography Using Dual-Source CT. AJR Am J Roentgenol 2007; 189:1317-23. [DOI: 10.2214/ajr.07.2711] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
144
|
Dual-source CT for chest pain assessment. Eur Radiol 2007; 18:773-80. [PMID: 18034246 PMCID: PMC2270358 DOI: 10.1007/s00330-007-0803-y] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Revised: 10/02/2007] [Accepted: 10/11/2007] [Indexed: 12/01/2022]
Abstract
Comprehensive CT angiography protocols offering a simultaneous evaluation of pulmonary embolism, coronary stenoses and aortic disease are gaining attractiveness with recent CT technology. The aim of this study was to assess the diagnostic accuracy of a specific dual-source CT protocol for chest pain assessment. One hundred nine patients suffering from acute chest pain were examined on a dual-source CT scanner with ECG gating at a temporal resolution of 83 ms using a body-weight-adapted contrast material injection regimen. The images were evaluated for the cause of chest pain, and the coronary findings were correlated to invasive coronary angiography in 29 patients (27%). The files of patients with negative CT examinations were reviewed for further diagnoses. Technical limitations were insufficient contrast opacification in six and artifacts from respiration in three patients. The most frequent diagnoses were coronary stenoses, valvular and myocardial disease, pulmonary embolism, aortic aneurysm and dissection. Overall sensitivity for the identification of the cause of chest pain was 98%. Correlation to invasive coronary angiography showed 100% sensitivity and negative predictive value for coronary stenoses. Dual-source CT offers a comprehensive, robust and fast chest pain assessment.
Collapse
|
145
|
Cody DD, Mahesh M. Technologic Advances in Multidetector CT with a Focus on Cardiac Imaging. Radiographics 2007; 27:1829-37. [DOI: 10.1148/rg.276075120] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
146
|
Stolzmann P, Scheffel H, Schertler T, Frauenfelder T, Leschka S, Husmann L, Flohr TG, Marincek B, Kaufmann PA, Alkadhi H. Radiation dose estimates in dual-source computed tomography coronary angiography. Eur Radiol 2007; 18:592-9. [PMID: 17909816 DOI: 10.1007/s00330-007-0786-8] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 08/15/2007] [Accepted: 09/11/2007] [Indexed: 10/22/2022]
Abstract
The purpose of this study was to quantify radiation dose parameters of dual-source CT coronary angiography. Eighty patients underwent contrast-enhanced, retrospectively ECG-gated dual-source CT coronary angiography with heart rate-adapted ECG pulsing using two algorithms: In 40 patients, the tube current was reduced to 20% (A(min1)) of the normal tube current (A(max)) outside the pulsing window; in 40 patients tube current was reduced to 4% (A(min2)) of A(max). Mean CTDI(vol) in the A(min1) group was 45.1 +/- 3.6 mGy; the mean CTDI(vol) in the A(min2) group was 39.1 +/- 3.2 mGy, with CTDI(vol) in the A(min2) group being significantly reduced when compared to the A(min1) group (P < 0.001). A significant negative correlation was found between CTDI(vol) and heart rate in group A(min1) (r = -0.82, P < 0.001), whereas no correlation was found between CTDI(vol) and heart rate in group A(min2) (r = -0.066). Using the conversion coefficient for the chest, dual-source CT coronary angiography resulted in an estimated mean effective dose of 8.8 mSv in the A(min1) group and 7.8 mSv in the A(min2). Radiation exposure of dual-source CT coronary angiography using an ECG-pulsing protocol reducing the tube current to 20% significantly decreases with increasing heart rates, despite using wider pulsing windows at higher heart rates. When using a protocol with reduced tube current of 4%, the radiation dose is significantly lower, irrespective of the heart rate.
Collapse
Affiliation(s)
- Paul Stolzmann
- Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich, Switzerland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
147
|
Einstein AJ, Moser KW, Thompson RC, Cerqueira MD, Henzlova MJ. Radiation Dose to Patients From Cardiac Diagnostic Imaging. Circulation 2007; 116:1290-305. [PMID: 17846343 DOI: 10.1161/circulationaha.107.688101] [Citation(s) in RCA: 633] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Andrew J Einstein
- Department of Medicine, Cardiology Division, Columbia University Medical Center, 622 W 168th St, PH 10-408, New York, NY 10032, USA.
| | | | | | | | | |
Collapse
|