osteoarthritis, tendonitis, muscle pull and strain,
femoral neck stress fractures, sports hernia or hidden/occult hernia
of oblique aponeurosis, or Obturator or ilioinguinal nerve entrapment.
You would need all or any of the following for diagnosis: Clinical examination by an orthopedic specialist, X-rays, blood tests, MRI or ultrasonnography.
MRI of pelvis will not pick up hip pathology unless targeted at that.
Hope this helps.