Radiographic Mensuration and Localisation: A New Method

Abstract

Some time ago I evolved the following technique for radiographic pelvimetry, because I found that each of the existing methods had certain disadvantages in practice. Chief of these are the following: 1. The majority of my cases are sent towards full term with a request for a report on the position, presentation, and full pelvic measurements. Now in order to estimate the position, two views are normally required: antero-posterior and true lateral, while the customary methods of X-ray pelvimetry require a semi-recumbent attitude of the patient. These are all of necessity exposures requiring a large intensity of radiation. It therefore became apparent that some method of obtaining pelvic measurements from the ordinary antero-posterior and lateral views was to be desired. 2. I had always used Thoms' method in preference to the others, but it seemed that one could never be sure that the perforated metal sheet was in the exact plane previously occupied by the pelvic brim, especially in obese patients. The method which I am about to describe appears to have many advantages. The first is that it could be used not only for radiological pelvimetry, but also for measuring certain internal organs, e.g., the sella turcica, and, most important of all, for localising opaque foreign bodies. By this method, one could calculate the depth of such a body exactly, in inches or centimetres, in a vertical line from the skin directly over it.