Chap 20, Vocabulary, Radiology and Nuclear Medicine Flashcards
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.
contrast studies
Radiopaque materials (contrast media) are injected to obtain contrast with surrounding tissue when shown on the x-ray film.
gamma camera
Machine to detect gamma rays emitted from radiopharmaceuticals during scanning for diagnostic purposes.
gamma rays
High-energy rays emitted by radioactive substances in tracer studies.
half-life
Time required for a radioactive substance to lose half its radioactivity by disintegration.
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.
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.
ionization
Transformation of electrically neutral substances into electrically charged particles. X-rays cause ionization of particles within tissues.
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.
positron emission tomography (PET)
Positron-emitting radioactive substances given intravenously create a cross-sectional image of cellular metabolism based on local concentration of the radioactive substance. PET scans give information about metabolic activity.
radioimmunoassay
Test combines radioactive chemicals and antibodies to detect minute quantities of substances in a patient’s blood.
radioisotope
Radioactive form of an element substance; radionuclide.
radiolabeled compound
Radiopharmaceutical; used in nuclear medicine studies.
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.
radiolucent
Permitting the passage of x-rays. Radiolucent structures appear black on x-ray images.
radionuclide
Radioactive form of an element that gives off energy in the form of radiation; radioisotope.
radiopaque
Obstructing the passage of x-rays. Radiopaque structures appear white on the x-ray images.
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).
scan
Image of an area, organ or tissue of the body obtained from ultrasonography, radioactive tracer studies, computed tomography, or magnetic resonance imaging.
scintigraphy
Diagnostic nuclear medicine test using radiopharmaceuticals and gamma cameras to create images.
singe photon emission computed tomography (SPECT)
Radioactive tracer is injected intravenously and a computer reconstructs a 3D image based on a composite of many views.
tagging
Attaching a radionuclide to a chemical and following its path in the body.
tracer studies
Radionuclides are used as tags, or labels, attached to chemicals and followed as they travel through the body.
ultrasonography (US, U/S)
Diagnostic technique that projects and retrieves high-frequency sound waves as they echo off parts of the body.
ultrasound transducer
Handheld device that sends and receives ultrasound signals.
uptake
Rate of absorption of a radionuclide into an organ or tissue.
ventilation-perfusion studies
Radiopharmaceutical is inhaled (ventilation) and injected intravenously (perfusion) followed by imaging its passage through the respiratory tract.
