A total body nuclear medicine bone scan is the best test for getting a picture of what areas of the skeleton are involved with FD/MAS. X-rays are often the best for viewing disease in long bones (legs, arms, etc.). A CT scan is the best way to assess FD/MAS in the skull. Ultrasound tests of the thyroid, testicles, uterus, and ovaries can sometimes be useful.
Blood tests that measure phosphorus, and thyroid hormones, etc. are critical. Read more.
It is essential to have vision (including visual fields) assessed by a neuro-ophthalmologist. An assessment of hearing is also useful. You can also reference the recommended treatment guidelines here.