Forty-slice spiral computed tomography of the coronary arteries: assessment of image quality and diagnostic accuracy in a non-selected patient population

Abstract

Purpose: To investigate prospectively the image quality and diagnostic accuracy of 40-slice computed tomography (CT) for the detection of hemodynamically significant coronary artery disease (CAD) in a non-selected, consecutive patient cohort.

Material and methods: Forty consecutive patients (28 men, 12 women) underwent both 40-slice CT and conventional invasive coronary angiography (ICA) within 10+/-7 days. The results of both methods were compared on a per-segment and per-patient basis, using ICA as the standard of reference.

Results: According to ICA, significant CAD was present in 30/40 patients (75%). Of a total of 545 segments, 43 segments (7.9%) could not be sufficiently evaluated by CT due to motion artifacts in 15 segments (34.9%), small vessel size and suboptimal contrast enhancement in 14 segments (32.6%), severe calcification in 10 segments (23.3%), and opacified adjacent structures such as cardiac veins in four segments (9.3%). Segment-based analysis for detection of significant stenosis >50% yielded an overall sensitivity, specificity, positive predictive value, and negative predictive value of 87%, 99%, 98%, and 95%, respectively. Restricting the assessment to clinically relevant proximal coronary segments led to an increase in sensitivity to 96%, specificity to 99%, and negative predictive value to 99%. Patient-based analysis demonstrated a high negative predictive value (91%) of CT for excluding significant CAD, even when all segments were included in the analysis.

Conclusion: In a non-selected patient population with a high prevalence of CAD, 40-slice CT demonstrates high diagnostic accuracy in the assessment of significant CAD per patient and per segment.