An in vivo imaging study of fascia thickness and muscle volume in the lower limb of healthy adult humans

Fascia is a connective tissue that influences movement and may play roles in muscle force transmission, pain sensation, and lymphatic function. To date, 3D imaging of fascia using MRI has not been achieved due to short T2* times of collagen-rich fascia. Here, we use ultrashort echo time (UTE) MRI sequences originally developed for cortical bone imaging to image lower limb fascia in healthy adults and examine fascia anatomy in vivo. We imaged the lower limbs of 30 healthy adults using 3T MRI with a dual-echo UTE sequence. Mean fascia thickness was 1.056 ± 0.208 mm in the thigh and 0.963 ± 0.089 mm in the calf. While thigh fascia thickness positively correlated with muscle volume and negatively with age, and calf fascia thickness showed a negative correlation with muscle and tibia volumes, these relationships were not statistically significant after adjusting for multiple comparisons. Thigh fascia thickness variation was greater in women than men. Further research may explore these relationships and develop models to probe the role of fascia in lower limb mechanics.