Abstract 11601: Single-Volume Quantitative CT Myocardial Perfusion Measurement - Validation in a Swine Model

Abstract

Introduction: Dynamic CT myocardial perfusion imaging enables accurate assessment of coronary artery disease (CAD). However, it is limited by the high radiation dose of serial acquisition of 10 or more volume scans per exam. Hypothesis: A single-volume quantitative CT myocardial perfusion technique can accurately measure perfusion in mL/min/g at a low radiation dose, as compared to microsphere perfusion measurement. Methods: The single-volume quantitative CT perfusion technique was validated in 6 swine (37 ± 8 kg). In each swine, several intermediate severity stenoses were induced in the left anterior descending (LAD) coronary artery using a balloon under intracoronary adenosine stress. Contrast-enhanced imaging was performed at 100 kVp and 200 mA with a 320-slice CT scanner, where 20 consecutive volume scans were acquired to capture the entire aortic enhancement curve. The image data were then used retrospectively to simulate prospective 2-mm-slice dynamic bolus tracking with aortic triggering at 150 HU followed by “acquisition” of a single volume scan at approximately the peak of the aortic enhancement: identical to a coronary CT angiogram. The dynamic bolus tracking, trigger, and single volume scan data were then used as analytical inputs into a novel first-pass analysis model to derive perfusion in mL/min/g. The accuracy versus microsphere perfusion was assessed via regression analysis. Results: Single-volume quantitative CT perfusion measurements (P CT ) were related to microsphere perfusion measurements (P MICRO ) by P CT = 1.00 P MICRO - 0.05 (Pearson’s r = 0.96; RMSE = 0.48 mL/min/g). The average CT dose index of the technique was only 5.4 mGy. Conclusions: The single-volume quantitative CT perfusion technique provides accurate, low-dose, myocardial perfusion measurement in mL/min/g using only bolus tracking images and a single volume scan. The technique can also provide simultaneous CT angiography when acquired at an appropriate radiation dose.