Medical Terminology Chapter 20 Vocabulary

tagging

Attaching a radionuclide to a chemical and following its path in the body.

ultrasonography (US, U/S)

Diagnostic technique that projects and retrieves high-frequency sound waves as they echo off parts of the body.

radiology

Medical specialty concerned with the study of x-rays and their use in the diagnosis of disease. It includes other forms of energy, such as ultrasound and magnetic waves. Also called diagnostic radiology.

ionization

Transformation of electrically neutral substances into electrically charged particles. X-rays cause ionization of particles within tissues.

ultrasound transducer

Handheld device that sends and receives ultrasound signals.

scintegraphy

Diagnostic unclear medicine test using radiopharmaceuticals and gamma cameras to create images.

Computed tomography (CT)

Diagnostic x-ray procedure whereby a cross-sectional image of a specific body segment is produced. Newer CT scanners can create 3D images as well.

scan

Image of an area, organ or tisue of the body obtained from ultrasonography, radioactive tracer studies, computed tomograpy, or magnetic resonance imaging.

gamma camera

Machine to detect gamma rays emitted from radiopharmaceuticals during scanning for diagnostic purposes.

magnetic resonance imaging (MRI)

Magnetic field and radio waves produce sagittal, coronal, and axial images of the body

nuclear medicine

Medical specialty that uses radioactive substances (radionuclides) in the diagnosis of disease.

radiopaque

Obstructing the passage of x-rays. Radiopaque structures appear white on the x-ray images.

radiolucent

Permitting the passage of x-rays. Radiolucent structures appear black on x-ray images.

positron emission tomography (PET)

Positron-emitting radioactive substances given intravenoisly create a cross-sectional image of cellular metabolism based on local concentration of the radioactive substance. PET scans give information about metabolic activity.

in vitro

Process, test, or procedure is performed, measured, or observed outside a living organism, often in a test tube.

in vivo

Process, test, or procedure is performed, measured, or observed within a living organism

radiopharmaceutical

Radioactive drug (radionuclide plus chemical) that is administered safely for diagnostic and therapeutic purposes; a radiotracer. An example is technetium 99m, which combines with albumin (for lung perfusion) and DTPA (for renal imaging).

radionuclide

Radioactive for of an element that gives off energey in the form of radiation; radioisotope.

radioisotope

Radioactive form of an element substance; radionuclide.

single photon emission computed tomography (SPECT)

Radioactive tracer is injected intraveniously and a computer reconstructs a 3D image based on a composite of many views.

tracer studies

Radionuclides are used as tags, or labels, attached to chemicals and followed as they travel through the body.

Contrast studies

Radiopaque materials (contrast media) are injected to obtain contrast with surrounding tissue when shown on the x-ray film.

ventilation-perfusion studies

Radiopharmaceutical is inhaled (ventilation) and injected intravenously (perfusion) followed by imaging its passage through the respiratory tract.

radiolabeled componed

Radiopharmaceutical; used in nuclear medicine studies.

uptake

Rate of absorption of a radionuclide into an organ or tissue.

radioimmunoassay

Test combines radioactive chemicals and antibodies to detect minute quantities of substances in a patient's blood.

interventional radiology

Therapeutic or diagnostic procedures performed by a radiologist. Examples are needle biopsy of a mass and drainage of an abscess, typically under the guidance of CT or Fluoroscopy

half-life

Time required for a radioactive substance to lose half its radioactivity by disintegration.