Abstract 2030: Absolute Quantification of Myocardial Blood Flow Using Dynamic Multidetector (64 Slice) Computed Tomography
Background: Dynamic multidetector computed tomography (d-MDCT) can track the kinetics of contrast media in the left ventricular (LV) blood pool and myocardium in real-time and thus has the potential for absolute quantification of myocardial blood flow (MBF). We applied a deconvolution analysis to d-MDCT derived input and myocardial time-density curves obtained in a large animal model of coronary stenosis during adenosine stress to determine the ability of d-MDCT to provide absolute quantification of MBF.
Methods and Results: Six canine models of moderate to severe left anterior descending artery (LAD) stenosis underwent d-MDCT imaging during adenosine infusion (0.14 ml/kg/min) according to the following imaging protocol: iopamidol 10 ml/sec for 3 sec, 8 mm × 4 collimation, 400 msec rotation time, 120 kV, 150 mA and microspheres were injected to document MBF. Images were reconstructed with an 8 mm slice thickness at 1 second intervals. Regions of interest were drawn in the LAD, left circumflex (LCX), and right coronary artery (RCA) territories and time-density curves were constructed. MDCT derived MBF was calculated in ml/g/min by deconvolution of the myocardial and input (LV blood pool) time-density functions. MBF by d-MDCT and microspheres in the LAD, LCX, and RCA territories was 1.8 ± 0.9 and 1.4 ± 0.9, 4.1 ± 2.5 and 3.4 ± 1.3, 4.2 ± 3.8 and 3.6 ± 2.8, respectively (p=NS). MBF calculated by MDCT overestimated MBF compared with microspheres, mean difference: 0.2 (d-MDCT Flow = 0.7218 μSph Flow = 1.0191, R = 0.90, p=0.001).
Conclusions: d-MDCT derived MBF measurements using deconvolution analysis correlate well with microsphere derived MBF with a systematic overestimation of MBF.