Kobylecka M, et al. – This study was carried out to evaluate the degree of myocardial fluorodeoxyglucose (FDG) uptake in glucose–loaded myocardial viability positron emission tomography/computed tomography (PET/CT) scans, to estimate the myocardial to background index, and correlate the index with image quality assessed on the basis of visual qualitative assessment. As evidence accumulates, the index ratio of 2.2, which is consistent with the upper borderline value for visually uninterpretable images, was considered the cut–off value for scans of optimal and non–optimal quality.