When should a left lateral decubitus radiograph of the abdomen be repeated?

A left lateral decubitus radiograph of the abdomen is particularly useful for visualizing free air or fluid levels. The inclusion of the diaphragm is crucial because it serves as a boundary for assessing whether there is free air in the peritoneal cavity, which can indicate conditions such as perforation of a hollow organ. When the diaphragm is not included, it limits the diagnostic quality of the image and may lead to false conclusions about the patient’s condition.

In this context, ensuring that the entire diaphragm is visible helps radiologists determine if there is any free air under the diaphragm, which would suggest abdominal obstruction or perforation. Therefore, if the diaphragm is not included in the image, the radiograph needs to be repeated to provide a complete assessment and avoid missing critical findings.