“…Several studies have recently documented the feasibility of MBF/MFR measurements by CZT technology in comparison to different reference standards, including positron emission tomography (PET) with N 13 H 3 or H 2 O 15 , 1-4 invasive coronary angiography, [5][6][7][8] magnetic resonance imaging, 9 flow fractional reserve, 5,10 and semiquantitative analysis of MPI. 11 Several of the previously cited papers were accompanied by editorial comments [12][13][14][15] which emphasized critical methodological limitations such as most clinical studies have been single site and enrolled a limited number of patients and the methodology is not standardized and varied from center to center.…”