Objective: In this study coronary arteries were compared and evaluated in 41 cases using multidetector CT with slice thicknesses of 2 mm and 1 mm. All 323 segments including #1-3, 5-8, and 11 [based on the American Heart Association (AHA) classification system] were used: 163 segments of 2 mm and 160 segments of 1 mm.
Methods: The images obtained were separated into fivelevels (0-4 points) of cardiac motion artifacts and evaluated based on volume rendering (VR) and partial maximum intensity projection (partial MIP).
Results: Of the results obtained, slice images of 1 mm in thickness were superior to those of 2 mm by 15.4% for sensitivity, 7.5% for specificity, and 8.2% for accuracy. On evaluation by segment, diagnostic accuracy was 2.88 +/- 0.57 for 2-mm slices and 3.28 +/- 0.59 for 1-mm slices of the left coronary artery, and 2.11 +/- 0.82 for 2-mm slices and 2.33 +/- 0.67 for 1-mm slices of the right coronary artery. Particularly for #6, a significantly high value was found for 1-mm slices (p < 0.05). Diagnostic accuracy was low in groups #2 and #3.
Conclusion: On the basis of these findings, we were persuaded of the usefulness of MDCT for the evaluation of coronary arterial stenosed lesions, and we consider that diagnostic capability is improved by using thinner slices. We concluded that further studies would be necessary for visualization of the right coronary artery, which was seriously affected by cardiac motion artifacts.