Cineangiographic measurements with the help of a vertebral grid system.

Cineangiographic measurements of cardiac structures require knowledge of the magnification factor due to nonparallelity of the X-ray beams. A new method is presented to determine the magnification factor from cineangiograms based on the patient's height and the height of three vertebral bodies and the adjacent intervertebral distances. The method enables measurement of cardiovascular structures from projected cineangiographic films where the appropriate magnification factor is missing. Furthermore, doubtful magnification factors can be checked out as to their accuracy.