Impact of Initial Helical Abdominal Computed Tomography on the Diagnosis of Hollow Viscus Injury and Blunt Abdominal Traumare

ABSTRACT

PURPOSE: This study was conducted to examine the clinical significance IV-contrasted helical abdomen computed tomography (CT) as a diagnostic screening tool to evaluate hollow viscus injury in blunt abdominal trauma patients. METHODS: This is a retrospective study encompassing 108 patients, presenting to Korea University Medical Center (KUMC) Emergency Department (ED) from January 2007 to December 2007, with an initial CT finding suggestive of intra-abdominal injury. An initial non-enhanced abdomen CT was taken, followed by an enhanced CT with intravenous contrast. Patients' demographic data, as well as the mechanisms of injury, were inquired upon and obtained, initial diagnosis, as dictated by specialized radiologists, were added to post-operational (post-OP) findings and to additional CT findings acquired during their hospital stays, and all were combined to arrive at final diagnosis. Initial CT findings were further compared with the final diagnosis, yielding values for sensitivity, specificity, and accuracy, as well as positive and negative predictive values. Patients were further divided into two groups, namely, those that underwent operational intervention and those that did not. The initial CT findings of each group were subsequently compared and analyzed. RESULTS: Initial CT scans revealed abnormal findings in a total of 212 cases - solid organ injuries being the most common finding, as was observed in 97 cases. Free fluid accumulation was evident in another 69 cases. Based on the CT findings, 77 cases (71.3%) were initially diagnosed as having a solid organ injury, 20 cases (18.5%) as having a combined (solid organ + hollow viscus) injury, and 11 cases (10.2%), as having an isolated hollow viscus injury. The final diagnosis however, were somewhat different, with only 67 cases (62.0%) attributed to solid organ injury, 31 cases (28.7%) to combined injury (solid + hollow), and 10 cases (9.3%) to hollow viscus injury. The sensitivity (CI 95%) of the initial helical CT in diagnosing hollow viscus injury was 75.6%, and its specificity was 100%. The accuracy in diagnosing hollow viscus injury was also meaningfully lower compared to that in diagnosis of solid organ injury. Among patients initially diagnosed with solid organ injuries, 10 patients (2 from follow-up CT and 8 from post-OP finding) turned out to have combined injuries. A total of 38 patients underwent an operation, and the proportion of initial CT findings suggesting free air, mesenteric hematoma or bowel wall thickening turned out to be significantly higher in the operation group. CONCLUSION: Abdominal CT was a meaningful screening test for hollow viscus injury, but the sensitivity of abdominal CT was significantly lower in detecting hollow viscus injury as compared to solid organ injury. This calls for special consideration and careful observation by the ED physicians when dealing with cases of blunt abdominal trauma.