Elevated F-18 FDG Uptake in the Psoas Muscle

Abstract

A 63-year-old man underwent a whole-body FDG PET study. On PET images, increased FDG uptake was noticed incidentally in the psoas muscles. The patient had exercised regularly every morning and night to prevent low back pain. The exercise routine was as follows: lying on his back with his hips and knees flexed and feet placed on the floor, he moved his knees together to the right and left repeatedly for 10 minutes. The psoas muscles, originating from the lumbar spine and inserting into the proximal portions of the femurs, were the target muscles in his exercise. Increased FDG uptake in these muscles was thought to be due to the effects of the exercise. It is not well understood how exercise training affects skeletal muscle glucose uptake. PET has been used in a growing number of situations, and this case suggests that PET could be used to investigate the effect of exercise on glucose metabolism in skeletal muscles.