Aortic dissection: sensitivity and specificity of MR imaging

Gated transverse magnetic resonance (MR) images of 54 patients (35 male, 19 female; aged 16-90 years) with suspected or known aortic dissection were reviewed by three cardiac radiologists without knowledge of clinical details. The reviewers independently determined the presence or absence and the type of aortic dissection. A confidence level was assigned for each diagnosis, and receiver operating characteristic curves were generated. The reviewer with extensive MR experience correctly identified 96% of the proved aortic dissections and all of the normal cases; the reviewer with moderate experience identified 96% and 84%, respectively; and the reviewer with minimal experience, 78% and 94%. The sensitivity at a specificity level of 90% was determined for each reviewer (100%, 96%, and 83%, respectively). MR imaging is highly sensitive and specific in the diagnosis of aortic dissection but does require considerable experience because of the need to recognize flow artifacts.