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Glossary of terms

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targeted cryoablation therapy
See cryosurgery.

targeted therapy
See monoclonal antibody therapy.

A radiotracer commonly used in nuclear medicine for many different types of examination. It decays within 24 hours, leaving no residual radiation.

One trained in and using the techniques of a profession, art, or science.

temporary brachytherapy
A radiation therapy treatment for cancer in which a sealed pellet (or “seed”) containing radioactive material is placed inside the body in or near a tumor for a specified amount of time and then withdrawn; can be administered at a low dose rate (LDR) or high dose rate (HDR).

temporomandibular joint disorder
Also known as TMJ.
A group of disorders associated with pain in the face affecting the jaw muscles, temporomandibular joints (upper temporal bone and lower mandible jaw bone that form the joint) and nerves.

tension headache
A headache in which pressure and a band-like tightness begins in the back of the head and upper neck and gradually encircles the head.

testicular torsion
The twisting of the spermatic cord that contains the vessels that supply blood to the testicles.

testis (pl. testes)
One of the two male reproductive glands that produce spermatozoa (sperm) and male hormones (testosterone). The testes are located behind the penis in the scrotum.

therapeutic radiology
A medical specialty and the study of radiation treatment of abnormal tissue (nonmalignant or cancerous) through the use of x-rays or radionuclides.

One professionally trained and/or skilled in the practice of a particular type of therapy.

Refers to the chest or ribs region of the spinal column, which includes twelve bones, or vertebrae labeled T-1 through T-12.

three-dimensional conformal radiation therapy (3D-CRT)
A form of external beam therapy that more precisely conforms the radiation to the tumor, allowing a higher radiation dose to be safely delivered.

See catheter-directed thrombolysis.

thrombolytic agent
One of a group of medications used to dissolve clots within the blood vessels of the body.

thrombolytic therapy
The use of medication used to break up or dissolve clots within blood vessels.

Inflamation of a vein that results when a blood clot, a thickened mass of blood, forms along the wall of a blood vessel.

The blocking of a blood vessel by a blood clot (or thrombus) that forms in a blood vessel or organ.

thrombotic stroke
A stroke that occurs when a blood clot forms in a cerebral blood vessel that is already very narrow.

thyroid gland
One of nine endocrine glands in the body, located in front of the neck just below the Adam's apple. It is shaped like a butterfly, with two lobes on either side of the neck connected by a narrow band of tissue. The thyroid gland produces thyroid hormones that set the rate the body carries on its necessary functions (metabolic rate). Some of the functions controlled by thyroid hormones include heart rate, cholesterol level, body weight, energy level, muscle strength, skin condition and vision.

thyroid scan
A nuclear medicine examination that helps evaluate the structure of the thyroid. The thyroid is a gland in the neck that controls metabolism, a chemical process that regulates the rate at which the body functions.

thyroid uptake
Also known as radioactive iodine uptake test (RAIU).
A nuclear medicine examination that helps evaluate the function of the thyroid. The thyroid is a gland in the neck that controls metabolism, a chemical process that regulates the rate at which the body functions.

tissue plasminogen activator (t-PA)
A blood clot-busting drug used to reduce the severity of an ischemic stroke if given within a short window of time following the onset of the stroke.

Making a radiographic image of a selected plane by means of reciprocal linear or curved motion of the x-ray tube and film cassette; images of all other planes are blurred ("out of focus") by being relatively displaced on the film.

tonic-clonic seizure
See grand mal seizure.

total body irradiation
A type of radiation therapy in which the entire body receives radiation prior to chemotherapy and a stem cell or bone marrow transplant.

total nodal irradiation
A type of radiation therapy that involves the delivery of radiation to all the lymph nodes in the body.

Also known as the windpipe, the tube that connects the lungs and mouth.

Through or across the abdomen.

A hand-held device that sends and receives ultrasound signals.

transient ischemic attack (TIA)
Often referred to as a mini stroke, a TIA is a temporary blockage in blood flow to parts of the brain, usually due to plaque or a blood clot. Symptoms typically go away within a day.

transjugular intrahepatic portosystemic shunt (TIPS)
A procedure that uses imaging guidance to connect the portal vein to the hepatic vein in the liver. A small metal device called a stent is placed to keep the connection open and allow it to bring blood draining from the bowel back to the heart while avoiding the liver. See the Transjugular Intrahepatic Portosystemic Shunt (TIPS) page for additional information.


  1. To transfer from one part to another, as in grafting and transplantation.
  2. The tissue or organ in grafting and transplantation.

Passing through or performed by way of the rectum.

Across or through the vagina (the genital canal in the female, extending from the uterus to the vulva).

treatment planning
Establishment of procedures to carry out effective radiation therapy with minimal risk to healthy tissue. See also simulation.

triple A
See abdominal aortic aneurysm (AAA).

A hollow needle with a sharply pointed end that is inserted into a blood vessel, body cavity or bone. Needles, tubes or other instruments are then inserted through the trocar be inserted to reach the treatment area.

A highly contagious infection transmitted through the air that attacks the lungs and other parts of the body.

A growth of abnormal cells that are either malignant or benign.

tumor ablation
The removal of a tumor.

tunneled cathether
A special type of catheter used in a vascular access procedure that is inserted inside a major vein for a period of weeks, or months so that blood can be repeatedly drawn or medication and nutrients can be injected into the patient’s bloodstream on regular basis. Unlike a standard intravenous catheter (IV) which is for short term use, a vascular access catheter is more durable and does not easily become blocked or infected. The tunneled catheter, which has a cuff at one end that stimulates tissue growth to help hold it in place, is used when access to the vein is needed for longer than three months and many times each day. This catheter is commonly used for patients requiring dialysis.

Veins that carry blood from throughout the body to the heart rely on a series of valves that work like gates to prevent blood from flowing backwards. When valves are not working properly, the normal flow of blood slows and creates pockets of backflow, called turgidity, where clots can develop.