The influences of blood glucose and duration of fasting on myocardial glucose uptake of [18F]fluoro-2-deoxy-D-glucose.

During the study of chest using positron emission tomography (PET) with [18F]fluoro-2-deoxy-d-glucose (FDG), a significant myocardial FDG uptake can prevent detection of the lesion that is located either behind or closely attached to the heart border. Two well-known and possible factors of myocardial FDG uptake are blood glucose level and fasting duration before FDG PET scanning. This study investigates whether the two factors are related to myocardial FDG uptake. Our study also explores the possibility of eliminating myocardial FDG uptake by controlling patients' blood glucose level and/or fasting duration. Whole-body FDG PET scans performed on 270 consecutive patients performed were reviewed. The study subjects were classified into four grades of myocardial FDG uptake according to the visual interpretation of the FDG PET image hard-copy films. For all study subjects, the blood sugar level and fasting duration before FDG injection were recorded. Then, the blood sugar levels and fasting duration were compared to the visual grade of myocardial FDG uptake for each study subject. About half of the study subjects showed graded 0 myocardial FDG uptake when the blood glucose levels were < or = 120 mg x dl(-1) or when the fasting duration was between 5 and 12 h. One hundred and thirty-one of the 142 (92%) patients with graded 0 uptake were asked to fast for > or = 4 h and had blood glucose levels < or = 120 mg x dl(-1). Based on our findings, we conclude that controlling the patients' blood glucose levels to < or = 120 mg x dl(-1) and at least 5 h fasting should be recommended to decrease myocardial FDG uptake. Copyright 2002 Lippincott Williams & Wilkins