Some physical characteristics of Potter-Bucky diaphragms.

The usefulness of the Potter-Bucky diaphragm in medical radiography is so well established that there is today no need of a general discussion of its properties. The contrast-reducing effect of scattered x-rays was recognized in the early days of radiography and led to the invention of the Bucky grid and its improvement by Dr. H. E. Potter. In a series of papers published more than thirty years ago, Wilsey (1–3) presented the results of quantitative determinations of the proportion of scattered radiation in the radiography of a water phantom under a variety of combinations of thickness, kilovoltage, and field size. These papers, which are now considered classics in their field, showed the increase in scatter with increase in each of these three variables. Of most interest in connection with the present investigation is Wilsey's study of the relation between the grid ratio of an idealized Bucky grid, composed of a single adjustable slit, and the efficiency of scatter removal (3). No measurements were repor...