Characteristics of mDIXON-Quant and proton magnetic resonance spectroscopy imaging of thigh skeletal muscles in patients with stroke-related sarcopenia: a prospective case-control study.

Background: This study was performed to investigate the imaging features of mDIXON-Quant and proton magnetic resonance spectroscopy (1H-MRS) of thigh muscles in patients with stroke-related sarcopenia (SRS).

Methods: This prospective case-control study was conducted in 40 patients with SRS, 40 patients without sarcopenia who had a stroke, and 40 healthy volunteers using mDIXON-Quant and 1H-MRS scanning. Skeletal muscle cross-sectional area (CSA) and fat fraction (FF) were analyzed.

Results: The skeletal muscle FF value was significantly higher (p<0.05) in patients with SRS and on the affected side. The extracellular fat content of the rectus femoris muscle in normal controls was 4× to 10× the intracellular fat content. A significant increase (p<0.05) in intracellular and extracellular fat content was detected in the SRS group. The degree of fat content increase in the SRS group was significantly lower (p<0.05) for extracellular fat than intracellular fat, with a ratio of extracellular to intracellular fat content of <4. The intracellular fat content was significantly higher (p<0.05) in the SRS group. A moderate-to-strong positive correlation existed between intracellular fat content (area 1) and muscle fat percentage. The degree of decrease in CSA in the posterior muscle group was significantly greater (p<0.05).

Conclusion: Thigh muscle CSA significantly decreased in SRS, while FF increased. The intracellular and extracellular fat content of the skeletal muscle was significantly increased, especially the intracellular fat content. SRS was confirmed when the ratio of extracellular fat content to intracellular fat content was <4.