Thoracic involvement of type A aortic dissection and intramural hematoma: Diagnostic accuracy - Comparison of emergency helical CT and surgical findings

PURPOSE: To assess the accuracy of various findings at emergency helical computed tomography (CT) for the evaluation of thoracic involvement of type A aortic dissection (AD) and type A intramural hematoma (IMH) and to compare these findings with those at surgical confirmation. MATERIALS AND METHODS: Fifty-seven patients with acute chest pain underwent emergency helical CT and subsequent surgery for type A AD or IMH. Patients in whom AD or IMH was detected in three segments of the thoracic aorta or those in whom there was a site of any entry tear, arch branch vessel involvement, pericardial effusion, or aortic arch anomaly were examined at helical CT. Sensitivity, specificity, and accuracy of helical CT, along with 95% CIs, were calculated by using surgical confirmation as the reference standard. RESULTS: For the detection of AD or IMH of the thoracic aorta, the accuracy of helical CT was 100%. The sensitivity, specificity, and accuracy, respectively, were 82%, 100%, and 84% for an entry tear; 95%, 100%, and 98% for arch branch vessel involvement, and 83%, 100%, and 91% for pericardial effusion. These values were all 100% for aortic arch anomalies. CONCLUSION: Emergency helical CT of the thorax depicts findings that are highly accurate in the evaluation of acute type A AD and IMH. (C) RSNA, 2003.