Diagnostic sensitivity of computerized tomography in closed trauma of the diaphragm. Retrospective study of 35 consecutive cases

PURPOSE: To evaluate the effectiveness and role of CT in blunt diaphragmatic injuries by reviewing our 8-year experience. MATERIAL AND METHODS: We reviewed the preoperative CT findings of 35 patients with surgically confirmed diaphragmatic rupture. Surgical repair was performed in the acute setting (within 12 hours of trauma) in 22 cases, and late (8 months-5 years) in 13 cases. Twenty-eight patients (80%) were examined with conventional CT and 7 (20%) with Helical CT. Scans were initiated at the thoracic inlet to the pubic symphysis, with 8-mm slice thickness, after i.v. contrast agent administration. Four-mm slices were acquired in the region of interest; sagittal and coronal reformations were obtained for Helical CT images. RESULTS: In the acute group, 20 patients had left hemidiaphragmatic and 2 right hemidiaphragmatic rupture; thoracic herniation of the abdominal organs was seen in all cases. Of the 13 patients examined long after trauma, the left hemidiaphragm was ruptured in 12 cases (with visceral herniation in 4), and the right hemidiaphragm in 1, with no herniation. The diaphragmatic rent was found in the dome (15 cases, 43%), musculotendinous junction (11 cases, 31%), muscular portion (8 cases, 23%), and at the muscular attachments on the ribs (1 case, 3%). CT diagnosed diaphragmatic rupture in all the acute cases (22/35 patients, 63%) and in 4 patients with visceral herniation (11%) examined long after trauma. CT findings were questionable in the 9 cases (25%) not presenting visceral herniation. As for the site of diaphragmatic injury, CT never depicted the diaphragmatic rent in the dome and at the musculotendinous junction (74%), not even with thin slices and the multiplanar Helical technique. CT detected indirects signs of injury at the muscular portion (23%), showing the injury site directly in the case with diaphragmatic avulsion (3%). CONCLUSION: CT is a reliable tool in the diagnosis of suspected diaphragmatic injury in the acute trauma setting. Long after trauma, CT performs poorly because it depicts the diaphragmatic rent only in some peripheral traumas. Helical CT has greater diagnostic potentials, but the injury site and type do affect its capabilities.