Acute renal infarction complicated by a sentinel loop in a patient with atrial fibrillation

A sentinel loop observed on plain radiography is a known sign of localized paralytic ileus that is primarily associated with acute pancreatitis, acute cholecystitis, and acute appendicitis. Here, we report a case of acute renal infarction (RI) complicated by a sentinel loop. A 58-year-old man with atrial fibrillation (AF) was hospitalized for paralytic ileus and was subsequently diagnosed with acute RI caused by embolism from the heart. Reports of sentinel loop signs on radiographs as a complication of acute RI are not available in previous English literature. For early diagnosis of acute RI and initiation of therapy to recover the function of the affected kidney and to prevent repeated thromboembolic events, it is important to recognize that a sentinel loop can be seen in acute RI as well as in other intra-abdominal inflammatory diseases.