The physiological uptake pattern of 18F-FDG in the left ventricular myocardium of patients without heart disease

Purpose : The purpose of this study was to evaluate the physiological uptake
pattern of 18F-FDG in the left ventricular myocardium of patients under preparation for
tumor FDG-PET. Patients and Methods : We enrolled 188 patients without cardiac disease.
The accumulation patterns were classified as either ‘none’, ‘diffuse’, ‘focal’ or ‘focal on
diffuse’. When a focal uptake was only observed on the basal wall, then the patterns were
classified as having either a ‘ring’, ‘over half’ or ‘spot’ uptake. Results : The frequencies
of the myocardial FDG uptake patterns were as follows : none, n=52 (27.7%) ; diffuse, n=
63 (33.5%) ; focal on diffuse, n=40 (21.3%) and focal, n=33 (17.6%). The age, blood glucose
level, weight and dose of FDG did not differ significantly for each pattern. The focal and
focal on diffuse patterns were seen in 73 patients, and 65 patients had a focal uptake only
on the basal wall ; ring uptake in 29 patients, over half in 20 and spot uptake in 16 patients.
Conclusions : The physiological myocardial uptake showed several patterns. Focal uptake
was often seen in patients with cardiac disease, but it did not always indicate an abnormal
finding when the accumulation was only on the basal wall.