No stone left unturned and nothing left behind - A pictorial guide for retained surgical items

Retained surgical instruments (RSI) remain an unsolved problem with serious implications for patients and healthcare providers. Although radiographs are commonly obtained whenever a surgical count is incorrect or incomplete, they have a very low prevalence of positive findings. With the majority of these studies being negative, it is difficult for radiologists and trainees to develop expertise in the detection of RSI, and comfort with reporting and documenting their findings. It is also important for the radiologist to be familiar with the documentation and communication requirements of their own institution in regards to intraoperative radiographs and their interpretation. This pictorial essay is intended to provide guidance to these "best practices" for the management of these cases. A series of case examples is also provided. In this manuscript we illustrate potential pitfalls and avoidable sources of error in the interpretation of these challenging cases.