CT with coronal reconstruction identifies previously missed smaller diaphragmatic injuries after blunt trauma.

Diaphragmatic injuries (DIs) are difficult to diagnose and often go unrecognized after blunt trauma. We proposed that CT scan with coronal reconstruction (CTCR) improves the detection of small DIs missed by chest x-ray (CXR) and CT scan with axial views (CTAX). We performed a retrospective review at a Level I trauma center from 2001 to 2006 and identified 35 patients who underwent operative repair of DI after blunt trauma. The size of the DI and the radiographic test (CXR, CTAX, and CTCR) that identified the defect was compared. Results were analyzed using mean, Mann-Whitney U test, and Fisher exact test. Of the 35 DI repairs, nine were performed after CXR alone and 12 after identification by both a CXR and CTAX. There was no significant difference between the mean DI size identified by CXR with and without CTAX (10.6 vs 9.7, P = 0.88). The remaining 14 DIs were undetected by CXR and CTAX. Seven of these (before CTCR) were found during exploratory laparotomy and seven were identified by CTCR (4.6 cm vs 3.5 cm, P = 0.33). The mean DI size identified by CTCR was significantly smaller than that identified by CXR alone (4.6 cm vs 9.7 cm, P < 0.05) and by CXR and CTAX (4.6 cm vs 10.6 cm, P < 0.0005). CTCR improves the ability to detect smaller DI defects (4 to 8 cm) that were previously missed by CXR and CTAX. CTAX adds little to CXR alone for the diagnosis of large defects (greater than 8 cm).