PAEA Surgery End Of Rotation (EOR) Practice Exam

Which method is primarily used to diagnose aortic dissection?

1. CT scan

2. X-ray

3. Ultrasound

4. MRI

The correct answer is: CT scan

The use of a CT scan is the primary method for diagnosing aortic dissection due to its speed, availability, and ability to provide detailed images of the aorta and surrounding structures. A CT scan, particularly with contrast, is highly effective in visualizing the layers of the aorta, allowing for the identification of a dissection and its extent, which is crucial for determining treatment. This imaging technique can quickly assess whether the dissection involves major branches or complications such as hemopericardium or aortic rupture. Other imaging modalities, while useful in certain contexts, do not provide the same level of detail or immediacy as a CT scan. X-rays may show indirect signs of aortic dissection, such as mediastinal widening, but they are not definitive and lack the specificity needed for a full diagnosis. Ultrasound may be helpful, especially in cases of suspected thoracic aorta involvement, but it is operator-dependent and less effective for a comprehensive view of the aorta compared to CT imaging. MRI offers detailed imaging and is useful in certain circumstances, particularly for chronic dissections or in patients who cannot undergo CT due to contrast allergies, but it is generally not the first-line diagnostic tool due to longer scan times and limited availability.