Image quality in a standardized algorithm for minimally invasive coronary angiography with multislice spiral computed tomography

Purpose: To report our experience with a standardized approach to pharmacologic heart rate control and image postprocessing for computed tomographic coronary angiography (CTCA) with multislice computed tomography (MSCT). Method: Two experienced observers used transaxial tomograms and maximum-intensity projections to classify coronary segments (12 per patient, 135 consecutive patients) for degree of stenosis. One factor affecting image quality was identified for each segment that could not be assessed. Results: Nine patients (7%) were excluded for technical reasons. Of 1,512 segments from 126 patients, 1,086 (72%) were assessable (8.6 per patient). Of 300 segments from 25 patients who also had selective coronary angiography, CTCA was able to assess 211 (70%) and detected significant disease in 27 (82% sensitivity, 96% specificity, 73% positive predictive value, and 97% negative predictive value). Vessel caliber, heart rate, and Agatston score were associated with inability to assess 426 coronary segments (28%). Conclusion: Heart rate and Agatston score are important predictors of the ability to assess proximal and midcoronary segments by CTCA with MSCT.