A 29-year-old Crossfit athlete presents to her sports medicine physician with a chief complaint of pain along the posterior leg that is worse after twenty minutes of sustained high-intensity interval training exercises. An MRI with the findings shown in Figure A is obtained, and she undergoes a treadmill test that demonstrates exercise-induced pain and cramping in the affected posterior leg, along with paresthesia along the posterolateral border of the leg and foot and diminished pulses with resisted ankle plantarflexion. Which of the following is the most likely diagnosis in this patient?