Fujita Medical Journal (Mar 2016)

A technique for quantitative measurement of myocardial blood flow using a combination of bolus tracking and time-registered helical multidetector CT angiography during adenosine stress

  • Takashi Ichihara,
  • Richard T. George,
  • Richard Mather,
  • Joao A.C. Lima,
  • Albert C. Lardo

DOI
https://doi.org/10.20407/fmj.1.1_9
Journal volume & issue
Vol. 1, no. 1
pp. 9 – 14

Abstract

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Objectives: The purpose of this study was to develop a quantitative method for myocardial blood flow (MBF) measurement using contrast-enhanced multidetector computed tomography (MDCT) images with bolus tracking and helical scanning. Materials and Methods: Nine canine models of left anterior descending artery stenosis were prepared and underwent MDCT perfusion imaging during adenosine infusion to study a wide range of flow parameters. Neutron-activated microspheres were injected to document MBF during adenosine infusion. Six animals underwent dynamic MDCT perfusion imaging, and K1 and k2 (which represent the first-order transfer constants from left ventricular blood to myocardium and from myocardium to the vascular system, respectively) were measured using a two-compartment model. The results were compared against microsphere MBF measurements, and the extraction fraction (E) of contrast agent and the mean value of k1/k2 were calculated. Six animals then underwent helical CT perfusion imaging, and neutron-activated microspheres were injected to document MBF during adenosine infusion. For each animal, based on E, K1/k2, time-registered helical CT myocardial data, and arterial input function data, tables of myocardial CT values versus MBF were simulated for various MBF values to create look-up tables from the myocardial CT value to MBF. The CT-derived MBF values were compared against the microsphere MBF measurements. Results: A strong linear correlation was observed between the MDCT-derived MBF and the microsphere MBF (y = 1.065x – 0.616, R2 = 0.838). Conclusions: Regional MBF can be measured accurately using a combination of bolus tracking and time-registered helical CT data from contrast-enhanced MDCT scanning during adenosine stress.

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