What is a radiologic procedure that is used to dilate a stenotic vessel?

Percutaneous angioplasty is a radiologic procedure specifically designed to treat stenotic (narrowed) blood vessels. This technique involves the insertion of a catheter into the affected blood vessel. Once positioned at the site of the blockage, a small inflatable balloon is then expanded. The inflation of this balloon serves two primary purposes: it physically widens the narrowed area of the vessel and helps restore normal blood flow.

The reason this procedure is optimal for addressing stenosis is that it not only helps alleviate symptoms associated with reduced blood flow but also minimizes the need for more invasive surgical interventions. The use of imaging technology, often fluoroscopy, during the procedure ensures the precise placement of the catheter and balloon.

In contrast, the other options—ultrasound, CT scan, and MRI—are imaging modalities that do not involve the intervention necessary to dilate a stenotic vessel. While these imaging techniques can be used to visualize blood vessels and identify stenotic lesions, they do not possess the capability to actively treat or dilate the vessels. Thus, percutaneous angioplasty stands out as the correct answer for directly addressing vascular stenosis.