Are inflammatory diseases of striated muscle with the former also showing skin involvement. They affect all ages but with greatest presentation in middle-aged women. They start as edematous swelling of muscles, which leads to fibrosis, calcification, atrophy, and contracture. The classic radiologic presentation shows soft tissue calcification: calcareous intramuscular calcification favoring proximal larger muscles and linear subcutaneous calcification with predilection for knees, elbows, and fingers
