Preparation for the procedure involves putting a drip in the arm. A CT scan involves lying on a narrow table which moves through the scanner as the images are acquired. The images only take a few seconds to generate. The procedure is very quick, and can always be performed as a day case. Like angiography it is not claustrophobic. 3. Magnetic Resonance Angiogram (MRA) An MR scan uses a magnetic field to generate images. Like CT it can create 3-dimensional images on a computer. Contrast (gadolinium) is injected into a vein in your arm. Any arteries in the body can then be viewed as a 2 or 3-dimensional image.