Three tissue layers called tunicae, or coats, surround the lumen of an artery. The adventitia (outer coat) is the outermost layer of an arterial wall and is composed of connective tissue containing elastic fibers and another layer of protein called the external basement membrane. Smooth muscle cells comprise the tunica media, or middle coat. The muscle cells contract or relax to constrict or dilate the artery.

See also Coronary Angiogram, Angiography, Angioplasty, and Cardiac Catheterization.

Interventional radiology is an area of clinical subspecialty which uses various radiology techniques (such as fluoroscopy, ultrasound, computed tomography, and MRI procedures) to guide procedures such as a biopsy, inserting catheters, place wires, draining fluids, dilating or stenting narrowed ducts or vessels to diagnose or treat different conditions.

See also CT Guided Biopsy, Angioplasty, Coronary Angiogram and Interventional Ultrasound.

(MIP) CT Angiography images can be processed by maximum intensity projection to interactively viewing volumes of data, where the CT number of each pixel is given by the minimum CT number through the volume. The MIP connects the high intensity dots of the blood vessels in three dimensions, providing an angiogram that can be viewed from any projection. Each point in the MIP represents the highest intensity experienced in that location on any partition within the imaging volume. For complete interpretation the base slices should also be reviewed individually and with multiplanar reconstruction (MPR) software. The MIP can then be displayed in a Cine format or filmed as multiple images acquired from different projections.

A venography (also called phlebography) is the imaging of veins. To perform a venography, a contrast agent is injected into a vein during a fluoroscopy, to show the details of venous structure and abnormalities as for example blood clots and occlusions. The examination of the veins is called venogram.
Other methods include contrast enhanced MR venography and venous ultrasound techniques.

See also Angiogram, CT Angiography, Digital Subtraction Angiography and Computed Tomography.