Diagnostic performance of coronary CT angiography with ultra-high-resolution CT: Comparison with invasive coronary angiography

Purpose: Recently, ultra-high-resolution computed tomography (U-HRCT) with a 0.25 mm × 128-row detector was introduced. The purpose of this study was to evaluate the diagnostic performance of coronary CT angiography (CCTA) using U-HRCT. Methods: This retrospective study included 38 consecutive patients with suspected coronary artery disease (CAD) who underwent CCTA with U-HRCT followed by invasive coronary angiography (ICA). Per-segment diameter stenosis was calculated. Diagnostic performance of CCTA relative to ICA as the reference standard was determined. For segments with >30% diameter stenosis, the correlation and agreement of percent diameter stenosis between CCTA and ICA were calculated. Results: Obstructive CAD was observed in 65 segments (12%) of 51 vessels (45%) in 32 patients (84%) during ICA. The per-patient, vessel, and segment analyses showed a sensitivity of 100% (95% confidence interval [CI], 95%–100%), 96% (95% CI: 89%–99%) and 95% (95% CI: 89%–98%), respectively, and a specificity of 67% (95% CI: 38%–67%), 81% (95% CI: 75%–83%) and 96% (95% CI: 96%–97%), respectively. The percentage of diameter stenosis, as determined by CCTA, demonstrated an excellent correlation with ICA (R = 0.90; 95% CI: 0.83–0.95) and a slight significant overestimation (mean: 4% ± 7%, p <.01), with the agreed range of limits being ± 16%. The median effective radiation dose for CCTA was 5.4 mSv (range: 2.9–18.0 mSv). Conclusions: CCTA with U-HRCT demonstrated an excellent correlation and agreement with ICA in the quantification of coronary artery stenosis.