Figure 1.

Delineation method for estimating whole-body pathologic uptake values (lesion load). All regions with standardized uptake value (SUV) >4 are first automatically delineated throughout the regions of interest. This is followed by manual exclusion of regions of physiologic uptake, such as the myocardium, kidneys, and bladder. The final contour represents the whole-body pathologic ¹⁸F-fluorodeoxyglucose uptake for the patient. Mean SUV, maximum SUV, total glycolytic activity, and total lesion volume are then calculated. Note that in this patient, myocardial SUV values were below the threshold of 4 and thus the heart was not included in the comprehensive volume of interest and did not need to be excluded afterward. Abbreviations: FDG, ¹⁸F-fluorodeoxyglucose; SUV, standardized uptake value.