What is the main advantage of rectangular collimation compared to circular?

The main advantage of rectangular collimation compared to circular collimation is that it reduces radiation exposure to surrounding tissues. Rectangular collimation is designed to closely fit the area of interest, resulting in less unnecessary radiation being directed to adjacent areas. By limiting the size of the X-ray beam more accurately to the region being imaged, this technique minimizes the dose of radiation to tissues that are not involved in the examination. This is especially important for patient safety, as reducing radiation exposure is a key principle in radiologic practice.

While ease of use, beam width, and speed may be considerations in the operation of X-ray equipment, they do not provide the same significant benefit regarding radiation safety as the more targeted approach of rectangular collimation does. Focusing the beam reduces scatter radiation, which not only benefits the patient but also helps in providing higher-quality images with less interference from surrounding tissues.