Effect of Sagittal Plane Positioning Errors on Measurement of the Angle of Inclination in Dogs


DVM, Radiology Section, New York State College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401


Angles of inclination were calculated from ventrodorsal (VD) and caudocranial horizontal beam (CaCrHB) radiographs of 17 anesthetized dogs, and from radiographs of left femurs of the same dogs positioned 0°, 10°, 15°, and 20° from the cassette in the sagittal plane. Angles of inclination also were measured directly from radiographs of the bones rotated to correct for anteversion. Calculated angles of inclination from the bones at 10°, 15°, and 20° from the cassette were significantly different from the 0° values obtained by calculation and direct measurement. Inclination angles from live dogs were consistently larger than those from 0° bones. Differences between angles of inclination calculated from VD and CaCrHB radiographs of live dogs were not significant.