A Simple and Accurate Method of Radiographic Pelvimetry

Abstract

These measurements should be taken as early in pregnancy as possible as it is then much easier to get a distinct and complete outline of the pelvic brim. In the later months it is much more difficult and throws a greater strain on the apparatus and tube. A. A “hatchet.” This is a piece of thin sheet lead, supported between layers of ply-wood, and shaped as shown. It is free to rotate at the end of a handle about eighteen inches long. Its concave portion is used to shade off the anterior portion of the patient's body during the radiographic exposure, as described later. B. A pair of obstetric callipers. C. A strip of lead, called a “rule,” about twelve inches long and two wide, supported by ply-wood. It has small holes drilled down the centre, exactly half-an-inch apart. From this “rule” the “pubic scales,” Fig. 2, are made in the following way. The “rule” is supported horizontally over the Potter-Bucky four and three-quarter inches above the surface, a film in a cassette being placed in the usual position...