1. A computer tomography scanning system comprising: a source that projects a substantially conically shaped X-ray beam along a path on to a subject such that at least a portion of said beam is transmitted through said subject; a detector array that detects the portion of the beam transmitted through the subject and operative to generate electronic signals in response to the beam transmitted through the subject that projects on to said detector array; a patient support structure for supporting the subject and rotating said subject about an axis intersecting with and substantially perpendicular to the path of the beam, wherein said subject is constrained such that the subject remains in the path of said beam; an airbag restraining mechanism attached to the support structure for holding the subject in its position; and an imaging mechanism operative to generate an image responsive to the electronic signals generated by the detector.