BEDNAREK DANIEL R. PhD; RUDIN, STEPHEN PhD; WONG, ROLAND ScMInvestigative Radiology: September-October 1983 Original Investigations: PDF Only Buy Abstract Methods are described for the assessment of patient exposure during clinical fluoroscopic procedures. Values of the roentgen-area-product (RAP) and their distribution throughout the examination are presented for both single-contrast and double-contrast barium enema studies. The double-contrast procedure was measured to give 50% more radiation to the patient than the single-contrast procedure when the same size optical aperture is used between the intensifier and TV pick-up tube. However, it was possible to decrease the fluoroscopic RAP value by over a factor of two for the double-contrast procedure without an adverse clinical effect by increasing the area of the aperture diaphragm. © Lippincott-Raven Publishers.