From the Guidelines
For a tortuous descending thoracic aorta noted incidentally on chest X-ray, the recommended initial investigations include a contrast-enhanced CT angiography (CTA) of the chest and abdomen as the first-line imaging study, as supported by the most recent guidelines 1. This provides detailed visualization of the aortic anatomy, accurate measurement of aortic dimensions, and assessment of any associated pathology. The American College of Radiology Appropriateness Criteria suggest that CT angiography and MR angiography are the most appropriate options for radiological diagnosis of suspected thoracic aortic aneurysm 1. Transthoracic echocardiography should also be performed to evaluate cardiac function and assess the aortic root and ascending aorta, as recommended by the European Society of Cardiology guidelines 1. Basic laboratory tests including complete blood count, renal function tests, and lipid profile are important to assess overall health status and cardiovascular risk factors. Blood pressure measurement in both arms is essential to detect significant differences that might suggest aortic pathology. A tortuous aorta is often a normal variant, particularly in elderly patients, but these investigations help distinguish between benign tortuosity and pathological conditions like aneurysm, dissection, or atherosclerotic disease. If the CTA shows significant dilation or other concerning features, referral to a vascular specialist is warranted for further management and possible surveillance imaging.
Some key points to consider:
- The initial imaging diagnosis of thoracic aortic aneurysm can be challenging, and providers should consider the level of invasiveness, relative radiation level, and quality of associated diagnostic data when choosing an imaging modality 1.
- The European Society of Cardiology guidelines recommend the use of CT angiography or MR angiography for the surveillance of patients with thoracic aortic aneurysms 1.
- Transthoracic echocardiography is useful for evaluating cardiac function and assessing the aortic root and ascending aorta, but it may not be sufficient for diagnosing aneurysms in the distal ascending aorta, aortic arch, or descending thoracic aorta 1.
- Chest X-ray is only of limited value for diagnosing aortic aneurysms, particularly if confined to the ascending aorta, and a normal aortic silhouette is not sufficient to rule out the presence of an aneurysm 1.
Overall, the recommended initial investigations for a tortuous descending thoracic aorta noted incidentally on chest X-ray prioritize the use of contrast-enhanced CT angiography and transthoracic echocardiography to provide a comprehensive evaluation of the aortic anatomy and associated pathology.
From the Research
Initial Investigations for Tortuous Descending Thoracic Aorta
The following are recommended initial investigations for a tortuous descending thoracic aorta noted incidentally on a chest X-ray:
- Computed Tomography (CT) angiography to confirm the diagnosis and assess the size, location, and extent of the tortuosity 2, 3
- Magnetic Resonance Angiogram (MRA) as an alternative to CT angiography to evaluate the aorta and its branches 2
- Transesophageal echocardiogram (TEE) to evaluate the aortic arch and descending thoracic aorta, especially if there are symptoms suggestive of dissection or rupture 2
Rationale for Investigations
The rationale for these investigations is to:
- Confirm the presence and extent of the tortuosity
- Assess for any complications such as dissection, rupture, or compression of adjacent structures
- Guide management decisions, including the need for monitoring, medical therapy, or surgical intervention 4, 5, 6, 3
Additional Considerations
Additional considerations in the evaluation of a tortuous descending thoracic aorta include: