Influence of Heart Rate on the Diagnostic Accuracy of Dual-Source Computed Tomography Coronary Angiography

ObjectivesWe evaluated the influence of heart rate on image quality and diagnostic accuracy of dual-source computed tomography (DSCT) coronary angiography.BackgroundMultidetector computed tomography (MDCT) coronary angiography has demonstrated an inverse relationship between heart rate and image quality. Dual-source CT provides a higher temporal resolution.MethodsOne hundred patients were studied by DSCT (DEFINITION, Siemens Medical Solutions, Forchheim, Germany). A contrast-enhanced volume dataset was acquired (two tubes, 120 kV, 400 mAs/rot, collimation 64 × 0.6 mm). Datasets were evaluated concerning the presence of significant coronary stenoses and validated against invasive coronary angiography.ResultsIn 44 patients with a heart rate ≥65 beats/min, 566 of 616 coronary segments were evaluable (92%), whereas in 56 patients with a heart rate <65 beats/min, 777 of 778 coronary segments were evaluable (100%, p < 0.001). On a per-patient basis, 93% of patients (≥65 beats/min) and 100% of patients (<65 beats/min) were considered evaluable. By classifying unevaluable segments as positive for stenosis, per-patient sensitivity was 95% (19 of 20) for heart rates ≥65 beats/min and 100% (22 of 22) for heart rates