A support apparatus for positioning a patient's head in an imaging apparatus. A main body has opposing first and second sides and supports first and second holding members for positioning against the patient's head. The first holding member has a first reference position along the first side of the main body and is coupled to a first transport apparatus that extends outward from the main body. The second holding member has a second reference position along the second side of the main body and is coupled to a second transport apparatus that extends outward from the main body. An extension locking mechanism within the main body locks the position of the second transport apparatus when the first holding member is moved from the first reference position and locks the position of the first transport apparatus when the second holding member is moved from the second reference position.
