Diagnosing penetrating diaphragmatic injuries: CT scan is valuable but not reliable.

Background: The diagnosis of penetrating isolated diaphragmatic injuries can be challenging because they are usually asymptomatic. Diagnosis by chest X-ray (CXR) is unreliable, while CT scan is reported to be more valuable. This study evaluated the diagnostic ability of CXR and CT in patients with proven DI.

Methods: Single center retrospective study (2009-2019), including all patients with penetrating diaphragmatic injuries (pDI) documented at laparotomy or laparoscopy with preoperative CXR and/or CT evaluation. Imaging findings included hemo/pneumothorax, hemoperitoneum, pneumoperitoneum, elevated diaphragm, definitive DI, diaphragmatic hernia, and associated abdominal injuries.

Results: 230 patients were included, 62 (27%) of which had isolated pDI, while 168 (73%) had associated abdominal or chest trauma. Of the 221 patients with proven DI and preoperative CXR, the CXR showed hemo/pneumothorax in 99 (45%), elevated diaphragm in 51 (23%), and diaphragmatic hernia in 4 (1.8%). In 86 (39%) patients, the CXR was normal. In 126 patients with pDI and preoperative CT, imaging showed hemo/pneumothorax in 95 (75%), hemoperitoneum in 66 (52%), pneumoperitoneum in 35 (28%), definitive DI in 56 (44%), suspected DI in 26 (21%), and no abnormality in 3 (2%). Of the 57 patients with isolated pDI the CXR showed a hemo/pneumothorax in 24 (42%), elevated diaphragm in 14 (25%) and was normal in 24 (42%).

Conclusions: Radiologic diagnosis of DI is unreliable. CT scan is much more sensitive than CXR. Laparoscopic evaluation should be considered liberally, irrespective of radiological findings.