Roentgen Methods for Routine Obstetrical Pelvimetry *

The application of roentgen methods to pelvimetry has been an interest in this dinic for the past fifteen years and during that time a number of communications on the subject have appeared as a result of our experience. In March, 1937, we described7 a modification of the technic for producing lateral roentgenograms, and since that time we have added this projection to our grid method of superior strait pelvimetry as a routine in all cases where roentgen pelvimetry is performed. Within recent months we have instituted a slight modification in our technic of the grid method,4 and it is the purpose of this paper to set down the essentials of both technics as they are used at present. WVithout the employment of both procedures in each individual we are convinced that an adequate survey of the pelvis is not possible. Furthermore, inasmuch as the mensuration of the anteroposterior diameter of the superior strait is possible in both technics, each procedure becomes an admirable check on the accuracy of the other. Any procedure in roentgen technic which is useful for routine clinical work must be simple, rapid, and accurate. All of these conditions seem to be approximated by the methods herein described. Our routine is to take the lateral projection first, and this technic may be described as follows: 1. The patient removes her dothing, putting on heelless slippers and the usual hospital bed-gown open at the back. 2. She is placed standing in front of an adjustable cassette changer, such as is used for chest work, with either the right or left lateral aspect of the body toward the target (Figs. 1 and 2). One arm rests on the top of the cassette changer and serves to steady the patient while the other is folded over the chest. The patient is told to distribute her weight equally on both feet. The use of the upright position for the taking of lateral pelvigrams is, of course, not new. Its use in obstetrical patients has been stressed by Garnett and Jacobs,' Vaughan,8 and others.