Is the possibility on the radiograph confirmed on MRI ? What is the diagnosis?
Yes. The diagnosis is avulsion injury to the proximal rectus femoris (straight head) at the anterior inferior iliac spine.
There is thickening as well as high signal and a small dehiscence in fat saturated images at the site of the direct head of left rectus femoris muscle at the anterior inferior iliac spine. This is consistent with proximal rectus femoris avulsion fracture.