Figure 4

T1-weighted MRI of upper and mid thighs, and legs according to disease progress, i.e., less than 20 years disease duration (A-F) and more than 20 years diseases duration (G-L). Posterior and anterior compartment muscle groups, especially vastus muscles groups, were severely involved in terms of total fatty atrophy, though fatty infiltration in the rectus femoris and sartorius thigh muscles was limited. Gracilis muscle was preserved despite of long disease duration (G-L). In the lower leg, deep and superficial posterior compartments were more severely affected by fatty atrophy than the anterior and extensor digitorum muscle group. However, total fatty atrophy was pronounced in those with a long disease duration, demonstrating the progressive nature of the disease.