Quantification of coronary stenosis by dual source computed tomography in patients: a comparative study with intravascular ultrasound and invasive angiography

Objective: To determine the accuracy of dual-source CT (DSCT) to quantify coronary stenosis compared to intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA).

Methods: 21 patients (23 vessels) were examined with DSCT, IVUS and invasive coronary angiography. Coronary minimal luminal diameter (MLD) and area (MLA) were measured in cross-sectional multi-planar reformatted images perpendicular to the vessel long-axis. The vessel cross-sectional area stenosis (MLA/CSA ratio) was calculated. DSCT results were compared with IVUS and QCA.

Results: A good correlation between DSCT and IVUS was noted for diameter and area stenosis (r=0.69 and r=0.73), with an overestimation of MLD stenosis by DSCT (+9.1%) and an underestimation of MLA stenosis (-5.8%). For MLD and MLA, high correlation coefficients (r=0.78 and r=0.90, respectively) were found between DSCT and IVUS; and the bias was almost zero (-0.41 mm and +0.1mm(2), respectively). The correlation between DSCT and QCA was moderate (r=0.60) for MLD stenosis with minor overestimation by DSCT (+4.0%) and moderate (r=0.59) for MLD (bias, +0.01 mm). The cross-sectional area stenosis showed a moderate correlation (r=0.59) between DSCT and IVUS (+0.00).

Conclusions: DSCT allows accurate quantification of coronary stenosis as compared to IVUS. An excellent correlation was found for the MLA between DSCT and IVUS.