Renal angiography is a medical imaging procedure used to examine in detail the blood vessels supplying the kidneys. This method is typically performed using X-rays after injecting a special contrast agent into the vessels. However, different imaging modalities such as computed tomography (CT angiography) or magnetic resonance imaging (MRI angiography) can also be used to evaluate the renal blood vessels. These techniques play an important role in detecting vascular narrowings, blockages, or other abnormalities.