Angiography

Angiography

Angiography is the procedure by which blood vessels of the body are visualised by injecting contrast or otherwise. Most popular contrast media are iodinated dyes which cast shadows of the vessels on X-ray imaging. Dyeless angiography is possible with magnetic resonance imaging where the signals from the moving hydrogen particles in blood give the image. This is known as magnetic resonance angiography. Angiography is done in a special procedure room known as cardiac catheterization laboratory, known in short as cathlab.

Conventional angio using X-ray equipment is used for imaging the blood vessels of the heart and is known as coronary angiography. Imaging of peripheral vessels of the limbs is known as peripheral angiography. Imaging vessels of the kidney is known as renal angiography. Cerebral angio is done to visualise the blood supply of the brain. Pulmonary angiography visualises the vessels of the lung. Intestinal blood supply is seen by mesenteric angio.

Contrast injected for angiography can cause some problems rarely. Rarely the individual can be allergic to the contrast dye. In an individual with compromised or borderline kidney function, the dye can precipitate kidney failure, which may sometimes require dialysis.

Most of the X-ray angiograms are done using iodinated dye injected into blood vessels through small tubes known as catheters. Small skin punctures are made under local anaesthesia to introduce these tubes into the body. Site of puncture depends on the type of angiography to be performed. Coronary angiography can be performed by puncture of the radial artery at the wrist or the femoral artery in the groin.

Cerebral and renal angiograms are usually done through the femoral route as the introduction of the catheter to these sites are easier by the femoral route. Same is true of angiography of the lower limb vessels and abdominal aorta. In case the lower limb vessels are not accessible due to occlusive disease, long catheters can be used from the upper limbs to access the lower limb vessels through the arch of aorta and descending aorta. Pulmonary angiography is done by accessing the femoral vein at the groin. It can also be achieved by a jugular puncture at the root of the neck, entering the veins which drain deoxygenated blood from the head and neck.