2016 Volume 2 Issue 1 Pages 58-60
15O-water has been considered to be a near-perfect and the most ideal myocardial blood flow (MBF) tracer because it is freely diffusible, metabolically inert, and independent of the myocardial metabolic state, which results in the highest extraction fraction. Absolute coronary flow reserve (CFR) is the ratio of MBF during maximal hyperemia in a coronary artery to MBF in the same artery under resting conditions and can be quantified noninvasively by positron emission tomography (PET). A growing body of literature is accumulating to show that the prognostic value of absolute MBF or CFR, which is quantified by cardiac PET.
ATP infusion protocol of 0.16 mg/kg/min for 5 minutes and its safety profile have been established in humans and it has been widely applied in many clinical and investigative studies including 15O-water PET. With the use of the 3-min acquisition data, the regions of interest in the left ventricular chamber and myocardium could be set for all of the subjects. Six-min CFR data could be used to separate the CAD patients and controls. A 3-min, but not 2-min, scan with 15O-water PET can be used for the quantitative evaluation of MBF and CFR. A shorter scan time will result in a reduction of body motion of patients, which may lead to the more precise quantification of MBF and CFR.
