Nuances of the unenhanced abdominal CT: careful inspection discloses critical findings.

Patients who have unenhanced abdominal CT scans are often critically ill. The unenhanced CT may reveal many unsuspected subtle abnormalities in the lower chest, abdomen, and pelvis and accordingly warrants careful attention. This article reviews unenhanced CT findings in the setting of pulmonary embolus, acute aortic syndromes, mesenteric and deep venous thrombosis, gastrointestinal hemorrhage, pancreatitis and its complications, as well as pyelonephritis.