MRI features of ERSA (exercise-related signal abnormality) lesions in professional soccer players

Fig. 1. Schematic diagram illustrating the 3 types of ERSA lesions encountered. The grey shading indicates the location of increased signal intensity on fluid sensitive images. a. Type A lesion with peritendinous ovoid region of increased signal. b. Type B lesion with subfascial ring of increased signal. c. Type C lesion with peritendinous ovoid region and subfascial ring of increased signal

Fig. 2. Type A ERSA lesion. a. Axial PDFS image of the thigh demonstrating peritendinous ovoid region of increased signal around the central tendon of rectus femoris (white arrow). b. Axial PDFS image of the thigh in a different patient demonstrating similar findings of peritendinous increased signal (white arrowhead) in rectus femoris muscle

Fig. 3. Type B ERSA lesion. a. Axial PDFS image of the thigh demonstrating a subfascial ring of increased signal in adductor longus (white arrow). b. Axial PDFS image of the thigh in a different patient illustrating a subfascial ring of increased signal in rectus femoris muscle (white arrowhead)

Fig. 4. Type C ERSA lesion. a. Axial PDFS image of the thigh illustrating a peritendinous ovoid region (white arrowhead) and subfascial ring (white arrow) of increased signal in rectus femoris. b. Axial PDFS image of the thigh in a different patient demonstrating a type C lesion in rectus femoris (white arrow) and a type B lesion in adductor longus (white arrowhead)

Fig. 5. Craniocaudal extent of ERSA and comparison with acute muscle injury. a. Coronal PDFS image of the thigh showing the craniocaudal extent of a type A ERSA lesion in rectus femoris (arrow). b. Coronal PDFS image of the thigh in a different patient illustrating an acute muscle injury of rectus femoris with similar craniocaudal length but with typical ‘feathery’ edema of acute muscle injury (arrowhead)