Abstract 19969: Combined Non-invasive Coronary Angiography and Myocardial Perfusion Imaging Using 320 Row Detector Computed Tomography: CT Perfusion Acquisition, Reconstruction, and Analysis Methods of the CORE-320 Multi-center Cohort Study
Introduction: CORE 320 is a prospective, 15-center study in 8 countries and 4 continents designed to validate the diagnostic accuracy of 320-detector row computed tomography (CT) for detecting coronary artery luminal stenosis causing myocardial perfusion abnormalities compared with gold standard conventional coronary angiography and radionuclide perfusion imaging. This study describes the scientific basis of the CORE 320 CT perfusion (CTP) acquisition, reconstruction, and analysis methods.
Methods and Results: Analysis included phantom and stress CTP data in 19 canine models of myocardial ischemia plus 75 patients. Animal models: dynamic adenosine stress 64 detector CT (DCT) demonstrated maximum attenuation differences in ischemic vs. non-ischemic territories occur in the upslope of the contrast bolus (56.7±20.2 HU) at a mean of 3.8±2.6 sec before peak arterial enhancement and these differences are less marked at peak enhancement, 40.4±18.9 HU. Helical CTP imaging targeted to the contrast bolus upslope confirmed these differences. Beam hardening correction: 256-DCT applied to myocardial phantoms plus 6 canine models demonstrated artifact correction and good correlation between CTP metrics and microsphere blood flow (R=0.84, p<0.001). Best cardiac phase: 43 patients imaged with 64 and 256-DCT with retrospective ECG-gated adenosine stress CTP had the least motion artifact at mid to end-diastole in 79% of cases. The mean best phase was 86% (range; 75–100%). 32 patients acquired with prospective ECG gated 320 CTP confirmed that minimum motion artifact occurs in mid to end-diastole during upslope to peak contrast enhancement. CTP attenuation for coronary lesions: CTP was quantitatively analyzed in 75 patients for the endocardial and epicardial attenuation. The ratio of the endocardial/epicardial HU for territories supplied by <50%, 50–70%, and >70% stenosed arteries was 1.11±0.11, 1.05±0.11, and 0.93±0.07; respectively (p<0.05).
Conclusion: CORE 320 prospective-ECG gated CTP images are acquired during the upslope to peak contrast enhancement, in mid to late diastole. Myocardial perfusion reconstruction kernels will apply beam hardening correction and be analyzed quantitatively for the presence of subendocardial perfusion deficits.
- © 2010 by American Heart Association, Inc.