What is the gold standard investigation for renal artery stenosis?

The gold standard investigation for renal artery stenosis is digital subtraction angiography (DSA). This imaging technique is particularly effective because it provides highly detailed images of blood vessels, allowing for clear visualization of the renal arteries and any potential stenoses. DSA involves the injection of contrast material into the blood vessels, followed by a series of images taken to differentiate between the vessels and surrounding tissues, enhancing the visibility of the arterial structures.

DSA is favored particularly in cases where anatomical detail and confirmation of blood flow dynamics are essential, such as in assessing the severity of stenosis and determining the appropriateness for interventional procedures. It has a high sensitivity and specificity for detecting renal artery disease, making it the preferred method when diagnosing this condition.

Other imaging techniques, while useful, do not provide the same level of detail or accuracy as DSA. For example, ultrasound can detect changes in kidney size and blood flow but may not clearly show the vessels themselves, particularly in patients with obesity or other anatomical challenges. CT scans can depict renal artery stenosis, especially with contrast enhancement, but they involve radiation exposure and may not always provide the detailed vascular images that DSA does. Magnetic resonance imaging, similar to CT, offers good soft tissue contrast and can visualize blood vessels