Diagnostic accuracy of image postprocessing methods for the detection of coronary artery stenoses by using multidetector CT

Purpose: To retrospectively evaluate the diagnostic accuracy of .multidetector computed tomography ( CT) coronary angiography for detection of hemodynamically significant ( >= 50%) stenoses by using various image postprocessing methods, with conventional coronary angiography as the reference standard. Materials and Methods: The analysis used data from previous studies, use of which had been approved by the Institutional Review Board. Sixteen-section multidetector CT data sets for 40 patients ( 30 men, 10 women; mean age 56 years +/- 8; mean heart rate, 61 beats per minute +/- 6) were evaluated. Six independent investigators evaluated the data sets for the presence of stenoses with diameter reduction of 50% or more, by using either exclusively transverse images, free oblique multiplanar reconstructions ( MPRs), free oblique maximum intensity projections ( MIPs, 5 mm thick), prerendered curved MPRs, prerendered curved MIPs, or prerendered three-dimensional volume rendered reconstructions ( VRTs). Evaluation results were compared with conventional coronary angiography for each artery in a blinded fashion ( chi(2) test). Results: Overall, 35 coronary artery stenoses were present. Percentage of evaluable arteries and accuracy for detecting stenosis ( percentages of accurately classified arteries were, respectively, 99% and 88% for transverse, 99% and 91% for oblique MPR, 94% and 86% for oblique MIP, 94% and 83% for curved MIP, 93% and 81% for curved MPR, and 91% and 73% for VRT). Accuracy was significantly higher for oblique MPR than for curved MPR ( P = .01), curved MIP ( P = .03), and VRT ( P < .001). Conclusion: The evaluation of multidetector CT coronary angiography with interactive image display methods, especially interactive oblique MPRs, permits higher diagnostic accuracy than evaluation of prerendered images ( curved MPR, curved MIP, or VRT images). (c) RSNA, 2007.