Light sources as a means of reproducing patient positioning

A simple method to insure the reproducibility of patient positioning is described. The system uses an adjustable frame fastened to the camera head and two light sources. The light sources project two circles of light on the patient. These reference points are marked on the patient's skin with a felt pen. If the patient moves or requires a follow-up study, these two reference points can be used to reposition the patient exactly. Comparison of the light-sources method with the persistence-scope method showed a significant improvement in accuracy with the former.