UMEM Educational Pearls

Oftentimes, CT imaging is used in diagnosis of emergent abdominal pathology. However, there may be instances where there is hesitancy to use IV contrast, whether due to patient factors or extrinsic factors (remember the contrast shortage during covid?) 

This study examines the diagnostic accuracy of dry CT. 3 quaternary centers with residency training programs participated, and contrasted images underwent further processing to remove any IV or oral contrast. Both residents and faculty reviewed the images, and findings were compared to both the initial read by radiologist as well as independent reads by a panel of experts. They looked for both primary findings (those that explained the abdominal pain) as well as actionable secondary findings (ie incidental findings requiring additional imaging or further management).

When compared to contasted imaging, the accuracy of dry CT was 70% (faculty, 68% to 74%; residents, 69% to 70%). Faculty had higher accuracy than residents for primary diagnoses but lower accuracy for actionable secondary diagnoses. 

Thus when considering the necessity of contrast, please consider the potential for missed diagnosis.


Shaish H, Ream J, Huang C, et al. Diagnostic Accuracy of Unenhanced Computed Tomography for Evaluation of Acute Abdominal Pain in the Emergency Department. JAMA Surg. 2023;158(7):e231112. doi:10.1001/jamasurg.2023.1112