Radiographic assessment of splenic injury without contrast: is contrast truly needed?

Introduction: Computed tomography (CT) has become an essential tool in the assessment of the stable trauma patient. Intravenous (i.v.) contrast is commonly relied upon to provide superior image quality, particularly for solid-organ injury. However, a substantial proportion of injured patients have contraindications to i.v. contrast. Little information exists concerning the repercussions of CT imaging without i.v. contrast, specifically for splenic injury.

Methods: We performed a retrospective analysis using data from our trauma registry and chart review as part of a quality improvement project at our institution. All patients with splenic injury, during a 3-year period (2008-2010), where a CT of the abdomen without i.v. contrast (DRY) early during their admission were selected. All splenic injuries had to have been verified with abdominal CT imaging with i.v. contrast (CONTRAST) or via intraoperative findings. DRY images were independently read by a single, blinded, radiologist and assessed for parenchymal injury or "suspicious" splenic injury findings and compared with CONTRAST imaging results or intraoperative findings.

Results: During the time period of the study, 319 patients had documented splenic injury with 44 (14%) patients undergoing DRY imaging, which was also verified by CONTRAST imaging or operative findings. Splenic parenchymal injury was only visualized in 38% of patients DRY patients. "Suspicious" splenic injury radiographic findings were common. When these less-specific findings for splenic injury were incorporated in the radiographic assessment, DRY imaging had more than 93% sensitivity for detecting splenic injury.

Conclusion: DRY imaging is increasingly being performed after injury and has a low sensitivity in detecting splenic parenchymal injury. However, less-specific radiographic findings suspicious for splenic injury in combination provide high sensitivity for the detection of splenic injury. These results suggest CONTRAST imaging is preferred to detect splenic injury; however, in those patients who have contraindications to i.v. contrast, DRY imagining may be able to select those who require close monitoring or intervention.