Technical Aspect of Coronary CT Angiography: Imaging Tips and Safety Issues.
10.5124/jkma.2007.50.2.104
- Author:
Whal LEE
1
Author Information
1. Department of Radiology, Seoul National University College of Medicine, Korea. leew@radiol.snu.ac.kr
- Publication Type:Original Article
- Keywords:
Computed Tomography;
Coronary artery;
Imaging technique;
Radiation dose
- MeSH:
Angiography*;
Cardiac Volume;
Contrast Media;
Coronary Angiography;
Coronary Stenosis;
Coronary Vessels;
Dilatation;
Electrocardiography;
Freezing;
Heart;
Heart Rate;
Iodine;
Nitroglycerin;
Radioisotopes;
Retrospective Studies;
Tomography, X-Ray Computed
- From:Journal of the Korean Medical Association
2007;50(2):104-108
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
CT coronary angiography is popular nowadays because of the wide use of multidetector CT. Multidetector CT has an isotropic resolution at 0.3~0.4 mm and temporal resolution at 80~210 ms. With the retrospective EKG-gated reconstruction technique and these high spatial and temporal resolutions, coronary artery imaging is possbile with CT. EKG-gated CT consists of EKG recording and continuous CT scanning with a low-pitch value. The CT data from certain periods of cardiac cycles, in which the cardiac motion is minimal, are retrospectively selected and reconstructed to whole heart volume data, and then the motion freezing entire heart CT image can be obtained. Because of its limited temporal resolution, EKG-gated CT requires lowering of the heart rate by beta-blocker medication in most cases. The lower heart rate increases diagnostic accuracy of coronary CT angiography. The nitroglycerin can also be used for coronary artery dilatation. Coronary CT angiography is a very reliable method for evaluating coronary artery stenosis with a noninvasive manner. The potential hazard comes from the use of ionized radiation and iodine contrast media. The typical radiation dose for coronary CT angiography is reported as 6.7 ~ 13.0mSv. This radiation dose is equivalent to those for other noninvasive coronary artery evaluating tools with radioactive isotopes and higher than the dose for conventional coronary angiography.
