|How images are obtained|
Angiography is a general term describing the imaging of blood vessels with x-ray dye. Arteriograms refer to imaging of arteries, while venograms refer to imaging of veins.
Angiograms are obtained by injecting radioopaque contrast material (x-ray dye-just like that used in CT) into a blood vessel. The contrast mixes with the blood in the vessel, and is propelled forward by cardiac action (arteriograms) or towards the heart with venous return (venograms). The flow of the blood/contrast mixture can be observed fluoroscopically, or a sequence of static x-ray images can be obtained.
Fluoroscopy is used to guide the placement and the positioning of the catheter into the blood vessel which is being studied.
The movie on the right is an arteriogram of the lower extremities. The catheter enters the right common femoral artery (catheter appears as a faint black line going across the right femur). The tip of the catheter is in the aorta, and this is where the contrast has been injected.