Computed tomography of splenic trauma

The purpose of this study was to illustrate and describe radiologic criteria of splenic injury, to recommend uniform reporting criteria of splenic injury, and to describe optimal scanning parameters relative to splenic injury. It consists of a retrospective blinded review of 66 patients with a discharge diagnosis of splenic injury who had abdominal computed tomography (CT) as part of their initial evaluation. The initial CT splenic diagnosis, the retrospective diagnosis, and the surgical description of injury were compared. The quality of the CT scan was evaluated with specific attention to the injection scan interval (ISI). ISI is defined as the time interval between the injection of intravenous contrast medium and the start of scanning. Scans with optimal ISI demonstrate maximal arterial opacification within the liver and spleen, renal parenchymal blush, but no contrast medium in the renal collecting system. Of the 66 patients, 31 (47%) had optimal scans, and 35 (53%) had extended scans. There were 22 surgically proven cases, 10 (45%) of which had extended scans. Of these 10 scans, five significantly undergraded the splenic injury when compared with the operative findings. Twelve of the 22 surgically proven scans (54%) had optimal timing, all of which correlated well with the operative findings. Twelve of the total group of patients (18%) had extended scans which demonstrated grade I or II injury; four of these patients required surgery. Similarly 12 patients (18%) had grade I or II injury and optimal ISI; however, all were managed nonoperatively. The optimal ISI was found to be 70 seconds (range, 60-90 seconds). When the ISI is greater than 90 seconds, splenic injuries are likely to be misdiagnosed or undergraded owing to venous filling, which obscures the detail of the splenic injury. Splenic injury may be undergraded or frankly missed by slow, low-resolution CT scanners, scans obtained with extended ISI, or scans without intravenous contrast medium. This study proposes an optimal CT scan technique that has eliminated discrepancies between radiologic interpretation of splenic injury and surgical findings. Splenic injuries can be classified on the basis of extent of injury, capsular tear, perisplenic hemorrhage, and hilar involvement. Active hemorrhage is the only absolute imaging indication for surgery.