What would you do if the scan was normal but the clinical suspicion was high?
None of the individual imaging modalities for AAD is perfect. One study created a decision model to determine the 30 day survival of patients who did, and did not, have a second test performed (not including TTE) when the clinical probability of acute dissection was high (>15%).
This review concluded that the 30 day survival of patients with a high probability of dissection was significantly improved when a second test was performed after the first test was negative [2].
Learning bite
It is imperative that if there is a strong clinical suspicion of aortic dissection and the result of the first modality of imaging is normal, a second test should be performed.