Objective: The purpose of this study was to determine the feasibility of global quantitative measurements of left ventricular myocardial perfusion derived from stress dynamic CT myocardial perfusion imaging.
Materials and methods: The coronary CT angiographic and CT myocardial perfusion imaging datasets of 146 patients were visually evaluated for the presence of coronary artery stenosis and perfusion defects. For the quantitative analysis, volumes of interest were defined over the entire left ventricular myocardium to obtain global myocardial blood flow (MBF), myocardial blood volume (MBV), and volume transfer constant (K(trans)).
Results: In patients without anatomically significant coronary stenosis or perfusion defects, the mean value of global MBF was 137.9 ± 28.8 mL/100 mL/min; MBV, 19.5 ± 2.3 mL/100 mL; and K(trans), 85.8 ± 15.2 mL/100 mL/min. In patients with perfusion defects in one, two, or three vessels, the mean global MBF values were 132.6 ± 29.2, 117.4 ± 4.9, and 92.5 ± 11.2 mL/100 mL/min; MBV, 17.9 ± 3.2, 16.1 ± 3.1, and 12.8 ± 1.7 mL/100 mL; and K(trans), 80.4 ± 12.9, 76.6 ± 13.8, and 72.6 ± 15.5 mL/100 mL/min. In patients with significant (> 50%) stenosis in one, two, or three vessels at coronary CT angiography, the mean global MBF values were 129.2 ± 28.3, 120.5 ± 24.2, and 119.4 ± 33.5 mL/100 mL/min; MBV, 17.8 ± 3.3, 17.2 ± 3.2, and 14.7 ± 4.1 mL/100 mL; and K(trans), 80.3 ± 12.9, 76.0 ± 14.7, and 77.6 ± 13.2 mL/100 mL/min.
Conclusion: Global quantitative assessment of left ventricular perfusion with stress dynamic CT myocardial perfusion imaging is feasible, and the findings correlate with the visual assessment of perfusion and the presence of coronary artery stenosis at coronary CT angiography. The potential clinical utility of this technique as a diagnostic tool for differentiating normal from globally reduced myocardial perfusion or as a prognostic marker merits further investigation.
Keywords: CT; coronary artery disease; myocardial perfusion; perfusion imaging.