Hi a friend of mine told me that when a doctor wants to find out if a person has dissociative identity disorder they take a x-ray of the neck?

No: Dissociative disorders are diagnosed through history and interview, not through xrays or laboratory methods. The process of ruling out certain physical conditions may include various diagnostic studies (including x-rays) though. Such physical conditions may accompany, complicate, or be mistaken for dissociative episodes -- think of problems like seizure disorders, hypothyroidism, etc.

Probably not: Did is a fairly rare and controversial diagnosis that is based on the idea of one's personality splitting up into several personalities, one of which is usually dominant. It is often associated with childhood abuse. There is no brain or neck imaging in clincial use at this time that can assist in the diagnosis or treatment of did.

Dissociative D/O: Can't be diagnosed with x-ray or lab test , ask u pcp and he will confirm that.