Maria Cristina Firetto MD, Presenter: Nothing to Disclose

Alessandro A. Lemos MD, Abstract Co-Author: Nothing to Disclose

Aldo M Marini MD, Abstract Co-Author: Nothing to Disclose

Ettore Contessini Avesani, Abstract Co-Author: Nothing to Disclose

Pietro R. Biondetti MD, Abstract Co-Author: Nothing to Disclose

To retrospectively evaluate the frequency and type of findings that were missed in the original report of multi-detector CT angiography (MDCTA) scan, in patients with suspected acute bowel ischemia who were subsequently operated.

From January 2007 until March 2011 a series of 35 patients (23 males, 12 females, mean age: 68.3 years) who underwent MDCTA of the abdomen and pelvis with a 4-slice scanner (G.E. Light-Speed, Wisconsin -USA), and surgery, were included in the study. The reports of the initial CT were retrospectively compared to the discharge diagnosis and operation reports. Discrepant or missing findings were analyzed for technical and/or diagnostic errors by reevaluating MDCTA images (Bowel wall thickness, bowel wall attenuation, gas in portal and/or mesenteric venous branches, gas in bowel wall, thrombotic obstruction of mesenteric veins and/or arteries) , and divided into (1) relevant, and (2) not relevant for the diagnosis. Strangulating obstructions (i.e.closed-loop obstruction) were excluded.  

In 23/35 patients (67%), all findings of bowel ischemia were correctly diagnosed in the initial MDCTA report. In the remaining 12/35 patients (33%) lesions that were not reported were present at surgery. In 10/12 (83%) patients the overlooked findings were relevant and subtle: gas in portal vein (n=3), gas in bowel wall (3), gas in portal vein and bowell wall (n=2), thrombotic occlusion of the distal branch of the superior mesenteric artery (n=1), thrombotic occlusion of the distal part of the inferior mesenteric artery (n=1). In 2/12 (17%) patients with bowel dilation and free fluid in whom the MDCTA overlooked findings were classified as non-relevant, bowel ischemia was found at surgery. With retrospective image interpretation, almost all patients (83%) with bowel ischemia due to vascular occlusion at surgery were correctly identified, whereas the remaining patients(17%) with non-occlusive ischemia at surgery showed non-relevant findings at MDCTA also at the retrospective analysis.

About 33% of relevant findings of bowel ischemia were overlooked by the initial MDCTA interpretation; mostly were subtle findings. However, secondary reading of MDCTA scans revealed most of these findings and can serve to improve diagnostic performance.

Secondary image reading in patients with suspected bowel ischemia helps to identify findings not detected at initial CT report.

Firetto, M, Lemos, A, Marini, A, Contessini Avesani, E, Biondetti, P, Acute Bowel Ischemia: Analysis of Diagnostic Error by Primarily Overlooked Findings at Multidetector CT Angiography.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11004548.html