E1182. It’s Harder Than it Looks! Deconstructing the Abdominal Plain Film
  1. Andrew Nguyen; University of Kentucky
  2. Preya Shah; Stanford University
  3. Luyao Shen; Stanford University
  4. Lindsey Negrete; Stanford University
An abdominal plain film can be a daunting but immensely fundamental topic to learn for radiology residents early in their training. It is important to have a firm grasp on the most important aspects in the evaluation of an abdominal plain film. These include the osseous structures, calcifications, foreign bodies, tubes, medical devices, free air, and bowel gas pattern. Mastering these principles will allow for radiologists to properly guide medical and surgical management of patients. Accurately interpreting these sometimes-subtle imaging findings can drastically change the course of patient care. In this exhibit, we aim to cover these important topics with easy to follow example cases, supplementary Computed Tomography/Magnetic Resonance Imaging (CT/MRI) images when available, and clear key takeaway points.

Educational Goals / Teaching Points
The teaching points in this exhibit will begin with a review of the normal anatomy and the basic radiographic densities (air, fat, gas, mineralization). Cases with usual and unusual abdominal calcifications will be showcased as well as appropriate characterization. The next teaching point will be the identification of foreign bodies, tubes, and medical devices on plain abdominal film. Each radiological image will have the correlate cross sectional imaging (CT or MRI) when available. Next, the exhibit will cover the presence of free air within the abdomen on plain film. Because the finding of free air needs to be recognized and urgently communicated, limited management will also be discussed in this section. Similarly, the identification of free fluid will be subsequently discussed such as ascites patterns. Finally, there will be a section on bowel gas pattern such as ileus and obstruction. This will cover diagnosis, localizing the site of obstruction, causes, and complications. This section will also include various teaching points, such as the rule of 3s, string of pearl signs, and the correlative findings on CT.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Key uses for abdominal film are to evaluate foreign bodies, bowel gas, and even abdominal calcifications. Important imaging findings include Rigler, Cupula, and Falciform ligament signs when evaluating for free gas. The imaging technique used will be the abdominal plain film.

For radiologists in training and even the seasoned attending, an abdominal film can be a surprisingly difficult modality. Whether it is the identification of a medical device or the timely detection of free air, the use of this imaging modality is immensely important for patient care. It is important for radiologists to have a solid foundation of this cornerstone study. Here, we cover the fundamentals of the abdominal plain film, we tackle challenging topics, and we address trainee questions of this seemingly simple yet at times allusive modality.