• Angiogram: An image of blood vessels produced by an x-ray using contrast medium.
• Arteriole: A small diameter blood vessel in the microcirculation that extends and branches from an artery and leads to capillaries.
• Beta Radiation: High-energy electrons that are sent out by radioactive nuclei ¹. 
• Catheter: A tube that is inserted into canals, blood vessels, passageways or body cavities for diagnostic or therapeutic purposes (to permit injection, withdraw fluids or keep a passage open).
• Cholecystitis: Inflammation of the gallbladder.
• Colorectal Liver Metastases: Cancer that originates in the colon or rectum and has spread to the liver ².
• Conscious Sedation: An induced state of sedation where the patient is able to remain responsive to verbal commands and physical stimulation as compared to being put 'completely under'.
• Duodenitis: Inflammation of the duodenum (the first, shortest and widest part of the small intestine).
• Embolize: A treatment that blocks the flow of blood in small blood vessels, such as those feeding a tumor.
• External Beam Radiotherapy: A method for delivering a beam or several beams of high-energy x-rays to a tumor. Beams are generated outside the patient (usually by a linear accelerator) and are targeted to the tumor site. No radioactive sources are placed inside the body ³.
• Femoral Artery: A large artery that starts in the lower abdomen and goes down into the thigh.
• Gastritis: Inflammation especially of the mucous membrane of the stomach.
• Hepatic Artery: The branch of the celiac artery that supplies the liver with arterial blood.
• Hepatic Arterial Chemotherapy: Chemotherapy delivered directly into the hepatic artery that mostly supplies blood to hepatic (liver) metastases and so exposes the metastases to high chemotherapy concentrations while minimizing damage to healthy liver tissue.
• Interventional Radiologist: Medical doctors who specialize in procedures that involve radiology including Selective Internal Radiation Therapy or SIRT.
• Mapping: The mapping process helps prepare the liver for treatment with SIRT. During the mapping procedure, the interventional radiologist may block (embolizes) any non-targeted vessel to minimize the potential for the microspheres to travel to areas outside of the liver.
• Portal Vein: A large vein that drains all blood from the stomach and the intestines into the liver.
• Prognosis: The forecast of the probable outcome or course of a disease.
• Radioembolization: A targeted treatment for liver tumors that delivers millions of tiny radioactive beads called SIR-Spheres^® Y-90 resin microspheres directly to the liver tumors. (Also known as Selective Internal Radiation Therapy or SIRT).
• Selective Internal Radiation Therapy (SIRT): A targeted treatment for liver tumors that delivers millions of tiny radioactive beads called SIR-Spheres Y-90 resin microspheres directly to liver tumors (Also known as radioembolization).
• Yttrium-90: Yttrium-90, or Y-90, is a radioactive element with a half-life of approximately 2.5 days that delivers beta radiation over a relatively short distance in human tissue.

1 http://dictionary.reference.com/browse/beta+radiation
2 http://www.hopkinsmedicine.org/liver_tumor_center/conditions/cancerous_liver_tumors/colorectal_liver_metastases.html
3 http://www.radiologyinfo.org/en/info.cfm?pg=ebt