Which diagnostic test should be performed first for a probable diagnosis of a dissecting aortic aneurysm?

In the case of a probable dissecting aortic aneurysm, a chest X-ray is typically performed first as it serves as a rapid and accessible diagnostic tool. The chest X-ray can help detect indirect signs of a dissection, such as widening of the mediastinum, displacement of the aorta, or potential pleural effusion.

This initial imaging test is valuable because it can be obtained quickly in emergency settings, allowing for immediate assessment. If the chest X-ray suggests the possibility of an aortic dissection, further imaging studies like a CT scan or MRI would then be considered to confirm the diagnosis and assess the extent of the dissection more accurately. While echocardiograms, CT scans, and MRIs provide detailed information and are important for evaluation, the chest X-ray serves as a quick and effective first step in ruling in or out an aortic dissection.