The polar format algorithm (PFA) is a well known method for forming imagery in both the radar community and the medical imaging community. PFA is attractive because it has low computational cost, and it partially compensates for phase errors due to a target's motion through resolution cells (MTRC). Since the imaging scenarios for remote sensing and medical imaging are traditionally different, the PFA implementation is different between the communities. This paper describes the differences in PFA implementation. The performance of two illustrative implementations is compared using synthetic radar and medical imagery.