van Straaten F J, van Aken J
Oral Surg Oral Med Oral Pathol. 1982 Sep;54(3):347-59. doi: 10.1016/0030-4220(82)90108-6.
Intraoral radiographs are often made with circular fields to irradiate the film, and in many instances these fields are much larger than the film. The feasibility of reducing a circular radiation field without increasing the probability of excessive cone cutting was evaluated clinically, and an optimum field size was determined. A circular radiation field 4.5 cm. at the tube end was found to minimize cone cutting and reduce the area of tissue irradiated by at least 44 percent. Findings suggest that current I.C.R.P. recommendations for a 6 to 7.5 cm. diameter circular field may be too liberal.
口腔内X光片通常采用圆形照射野来照射胶片，在很多情况下，这些照射野比胶片大得多。临床上评估了在不增加过度切角可能性的情况下缩小圆形辐射野的可行性，并确定了最佳野尺寸。发现管端4.5厘米的圆形辐射野可将切角降至最低，并使受照射组织面积至少减少44%。研究结果表明，国际辐射防护委员会（I.C.R.P.）目前关于直径6至7.5厘米圆形照射野的建议可能过于宽松。
