Figure 1
From: Muscle fat replacement and contractility in patients with skeletal muscle sodium channel disorders
Overview of MRI. (A) Localizer shows the 6 different levels of segmentation on the leg. (B) Example of muscle mapping of the thigh (50%) and calf (33%). (C) T1-w MRI of a 59-year-old patient heterozygous for p.T1313M at 50% length of the thigh. (D–F) Series of T1-w MRI from the same patient at 23, 33 and 43% of the calf, demonstrating significant proximal–distal difference of involvement. In the more distal part of the muscle (at 33% length of the tibia), the gastrocnemius medialis is almost completely replaced by fat.
