IR Dictionary

Interventional Radiology uses a lot of complex and technical terms. Medical students or junior trainees can often find it difficult to understand a lot of the common terminology used in the day-to-day practice of IR. Here, we have listed some common terms that are used, with easy to read explanations of what they are.

Written by Dr Nick Lorch, Radiology Trainee in Leeds.

Ablation

Using heat, electricity or freezing to destroy tissue. Can be used for cancer, or also to destroy nerves in chronic pain.

Aneurysm

A widening of a blood vessel or duct over 150% of the normal diameter. For example, an abdominal aortic aneurysm. As these grow, the risk of rupture increases.

Angiogram

An imaging study which displays a vessel. This is usually done by injecting iodine contrast into a vessel while video-ing it live with a fluoroscopy x-ray camera. There is also CT angiography, and MR angiography, which can show blood as it moves through magnetic gradients, without injecting contrast

Angioplasty

Remoulding of a vessel. This usually refers to atherosclerotic arteries which can be stretched with balloons to widen the lumen.

Aspiration

Pulling back on a syringe to remove liquid contents. This means a needle is passed into an abscess or cyst to remove fluid, but a long-term drain is not left in. A “Fine Needle Aspirate” is really a biopsy of suspected cancer.

Biopsy

“Examination of tissue from a living body.” A chunk of tissue can be cut with a co-axial needle. Where a Fine Needle Aspirate delivers cells, a biopsy sample is bigger, and the tissue architecture has not been destroyed.

Catheter

Simply means a tube! You are probably most familiar with the Foley catheter for draining the bladder. A catheter and wire combination can together be used to navigate through blood vessels, and the catheter can be used to inject contrast for angiograms. There are also drainage catheters that can be placed in abscesses.

Coil

Metal wires that coil up when deployed. This provokes clot formation, to block a blood vessel or aneurysm.

Collateral

Simply means another pathway for blood to flow. This can refer to the new smaller vessels which form to bypass a stenosis.

Cone beam CT

moving the x-ray tube and flat-panel fluoroscopy equipment around the patient, to take 3-D images. This is similar to the spinning tube and detector inside a CT.

Contrast

Anything introduced to the body to improve detail on imaging. For x-ray and CT, this is usually iodine contrast which can be injected into veins, arteries, the urinary or biliary system, orally, or into the vertebral canal for a myelogram.

Drain

A temporary tube (catheter) which is placed and secured to allow drainage of infection or fluid.