Paul C. Hodges

Heart Size from Routine Chest Films

Roentgen ray determination of the size of the human heart may be extremely precise if one employs sufficiently refined technics, such as those for volume, or a mere approximation if the subjects have heart disease and the criterion of size is the transverse diameter of the frontal plane silhouette. Estimation of frontal plane area from orthodiagrams or from specially made films constitutes a practical compromise between these two extremes, and tables and equations have been developed for predicted normal area from height and weight. The general radiologist faces daily the task of passing judgment on the shape and size of the hearts that he sees in routine chest films. In our laboratory such films invariably are stereoscopic and are accompanied by a record of the patients height, weight, and anteroposterior chest diameter. Exposure times range from 1/30th of a second to 1/10th of a second, depending on the thickness of the chest, and there is no attempt to synchronize exposures with a particular point in ...

THE RADIOLOGIST LOOKS AT RADIATION HAZARDS

When geneticists, biophysicists, and radiologists sit down together for a full-day conference, as they did recently in St. Louis under the sponsorship of the National Research Council (1), they find themselves essentially in agreement about the genetic and other health hazards of ionizing radiations of all sorts and the measures that should be taken to reduce those hazards to a minimum. But prosaic facts may have little reader appeal and unfortunately a few of the people who make their living writing for the popular magazines find it profitable to whoop it up whenever they smell the faintest odor of disagreement. Certainly the exposure of human tissues to ionizing radiations should be kept as low as is practical. There are many safeguards that can be built into x-ray apparatus and incorporated into x-ray technics to reduce the tissue dose for a particular examination, and certainly it is important to avoid unnecessary examinations. I shall attempt here to epitomize the clinical implications of the work of...

Pelvic Dimensions in Eutocia and Dystocia

In an earlier paper in this journal, we have described a method for measuring the maternal pelvis by means of true dimensional tracings or orthograms that portray the mid-sagittal plane and the inlet, mid-pelvis, and outlet. For obstetrical hospitals or other institutions having a good deal of pelvimetry to do, the objective precision of the orthographic method is desirable and the cost not prohibitive; but in other situations, where the volume of work does not warrant the purchase of a 90° table and a pantograph, equally precise work may be done with simple inexpensive apparatus, provided the radiologist exercises skill and care in making and working up the roentgenographs. The present paper is concerned with the clinical and roentgenological findings in 912 primiparous white women who were studied throughout pregnancy, including delivery. It had been our hope to report on an even thousand but 88 records had to be excluded, in most instances because the patient could not be followed through delivery. The...

Pelvic Roentgenography in Pregnancy1

THE most important roentgenologic contributions to obstetrics are non-quantitative, require little or no special apparatus, and call for only such experience and knowledge as are possessed by all qualified radiologists. Prominent examples of this group are: (1)Diagnosis of pregnancy. (2)Differentiation between single and multiple pregnancy. (3)Diagnosis of fetal attitude, presentation, and position. (4)Diagnosis of such perversions of pregnancy as ectopic pregnancy, missed abortion, hydatidiform mole. (5)Demonstration of fetal deformities or disease. (6)Estimation of amount of amniotic fluid and location of the placenta. (7)Determination as to whether the fetus is alive or dead. (8)Thoroughgoing qualitative survey of maternal pelvis. Quantitative studies of the pelvis and fetus require somewhat specialized equipment and experience. One of us (P. C. H.) has recently discussed the general principles underlying all roentgen pelvimetry and fetometry (1) and most of the positions, equations, graphs, technics, ...

Skeletal Changes in Disturbances of the Parathyroid Glands1

Introduction Knowledge as to the function of the parathyroid glands has been built up from observation in several fields. Previous to 1924, the principal physiologic approach was to observe the sequelae of extirpation of the glands in animals. Since 1924 (9), it has been possible to reverse the situation by the injection of Collips parathyroid extract (18 and 17). In 1926, Mandl (20) demonstrated that a corresponding hyperparathyroidism occurs spontaneously in patients suffering from parathyroid adenomas, and quite recently it seems to have been established that the same condition may follow simple hyperplasia of these glands (3) under the influence perhaps of an over-production of hormone by the anterior lobe of the pituitary (11 and 15). Arguing from clinical and laboratory studies on material of this sort, it is now generally believed that hyperparathyroidism, either spontaneous or induced, causes an excessive amount of calcium and phosphate to pass from the bones into the blood, resulting eventually ...

An Evaluation of Automatic Exposure Control Equipment in Photofluorography

History of Automatic Timer Development Late in the summer of 1940, investigations were undertaken at the University of Chicago to develop equipment whereby radiographic exposure might be more effectively controlled than was possible by the customarily used anatomic measurement technic. Because the problems associated with exposure control in radiography are fundamentally similar to those in photography, the first work (4, 5) was directed toward the development of a roentgen-ray exposure meter comparable in principle and operation to the instruments commonly employed in photographic practice. This early research clearly demonstrated that, with care in design, an instrument whose performance is entirely satisfactory from the standpoint of consistency of results is not difficult to produce. At the same time, it appeared equally evident that such a device is not likely to be widely accepted because of certain inherent characteristics which limit its usefulness. For example, when an exposure meter is used to c...

An improved X-ray phototimer.

In the first x-ray phototimers, which were developed in this laboratory (University of Chicago) approximately six years ago, Morgan (1) employed a hot cathode thyratron (RCA 2051) as the trigger and connected its grid to the 9th dynode of the multiplier phototube (931). He was forced to abandon this arrangement, however, because of relatively poor internal insulation in the dynodes of the phototubes available at that time and to employ instead as the control electrode the better insulated anode. The output of this anode fed the control grid of a pentode (6J7) and thus an amplified voltage of the desired sign was supplied to the grid of a cold cathode trigger tube (1C21). Now that better insulated phototubes have become available (1P21 with mica-filled base), it is possible to revert to the 9th dynode as the control electrode. Recently, aided by the expert advice and assistance of Professor Robert Moon and Mr. Karl Norris of our Institute of Radiobiology and Biophysics, we have designed new phototimers to ...