Abstract 2589: Combined Perfusion and Non-Invasive Coronary Angiography in Patients with Suspected Coronary Disease using 256 Row, 0.5 mm Slice Thickness Non-Helical Multi-Detector Computed Tomography
Introduction: Full volumetric cardiac imaging over a single heart beat using a 256 row multidetector computed tomography scanning system provides distinct advantages over the current generation of MDCT scanners. 256x0.5mm MDCT allows for a protocol that combines MDCT angiography (MDCTA) with rest and stress CT perfusion (CTP) imaging. The purpose of this study was to test the accuracy of combined 256x0.5mm MDCTA and CTP in patients with suspected coronary artery disease.
Methods: Nineteen patients with a positive single photon emission computed tomography (SPECT) perfusion study were imaged by 256 row MDCT with 0.5mm slice thickness (12.8 cm coverage) during one heart beat in a non-helical mode. Stress CTP (120kV, 100mAs, 3 gantry rotations at 0.5 secs, 7.7mSv dose) during adenosine infusion (140μg/kg/min) was followed by rest CTP and CTA (120kV, 175mAs, 3 gantry rotations at 0.5 secs, 13.5mSv dose). Using a territory based analysis; rest and stress CTP images were visually assessed for subendocardial perfusion deficits, CTA was evaluated for stenoses ≥50%, and SPECT images were evaluated for reversible and fixed perfusion deficits. In a second analysis the gold standard for ischemia secondary to epicardial atherosclerosis was defined as a SPECT perfusion deficit in a territory supplied by a coronary artery with a stenosis ≥50%.
Results: Compared to ≥50% stenosis by CTA, the sensitivity and specificity of CTP was 85% and 77% compared to 69% and 74% by SPECT. More importantly, when considering the combination of ≥50% stenosis by CTA and a corresponding perfusion deficit on SPECT as the gold standard for ischemic CAD, the sensitivity and specificity for combined CTA and CTP imaging was 78% and 90%. The area under the ROC curve for the combination of CTA and CTP was 0.84, p<0.001.
Conclusions: In patients with suspected coronary artery disease, 256x0.5mm MDCT enables the combination of non-invasive CT angiography and CT perfusion imaging with high accuracy and at radiation levels similar to currently used dual isotope nuclear imaging techniques.