Abstract 3827: Assessment of Significant Coronary Artery Stenoses with Computed Tomography (CT) Number of the Contrast Medium in the Reference Lumen Proximal and Distal to the Stenotic Lesion by Multislice CT (MSCT)
Background: MSCT is a recently developed modality, which may achieve high level of reliability and accuracy in the visualization of coronary artery. However, false positive rate of the examination is relatively high, mainly due to severe calcifications and residual motion artifacts.
Purpose: We measured CT number of the contrast medium in coronary arteries proximal and ((CT number proximal to a lesion - that distal to the lesion) divided by the CT number proximal to the lesion × 100%) and a degree of stenoses assessed by coronary angiography (CAG).
Method: We enrolled 42 patients (35men, mean age 67±10 years) who underwent both CAG and MSCT using a scanner with 40 detector rows. We evaluated 100 segments and they were classified as normal (33/100), 50% stenosis (27/100), 75% stenosis (11/100), or 90–100% stenosis (24/100) according to the results of CAG.
Result: The percent change of the CT number were 3.3±3.7% in normal segments, 6.6±8.1% in 50% stenotic lesions, 19.7±14.2% in 75% stenotic lesions, and 22.2±16.8% in 90–100% stenotic lesions. There was a significant difference between the percent change of the CT number in non-significantly stenotic segments (<50%) and that in significantly stenotic lesions (>75%). Furthermore, there was a significant correlation between the percent change the CT number by MSCT and the degree of stenoses by CAG(r=0.65).
Conclusion: The measurement of the CT numbers of the contrast medium in the coronary artery lumen proximal and distal to the stenosis by MSCT may provide higher accuracy in the assessment of the degree of the coronary stenosis. This method would be useful in the assessment of the coronary artery stenosis in cases with severe calcification even if it is difficult to assess the stenosis directly.