Assessment of hind limb muscle activity after stair-climbing in a dog using 18F-FDG PET/CT: A case report

Abstract

Accurate assessment of functional muscle activation is important for planning rehabilitation exercises in canine patients. Conventional methods, such as electromyography and gait analysis, have limitations in evaluating deep muscles and providing a comprehensive assessment of muscle activity. This case study used ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) to assess hind limb muscle activity in a dog after stair-climbing exercise. A 4-year-old castrated male Beagle underwent 1 h of stair-climbing exercise followed by FDG PET/CT scanning. Increased FDG uptake was observed in multiple hind limb muscles, particularly the gluteus medius and quadratus femoris muscles. The quadratus femoris, a deep muscle that is difficult to assess using conventional methods, showed prominent FDG uptake among the hind limb muscles evaluated. Differences in FDG uptake were also observed between the semitendinosus and semimembranosus muscles despite their similar functions. Relatively lower uptake was noted in the psoas major and psoas minor muscles involved in hip flexion. These findings suggest that FDG PET/CT may be useful for evaluating exercise-related muscle activity, including activity in deep muscles, in dogs.