Chap 20, Vocabulary, Radiology and Nuclear Medicine

Question 1

computed tomography (CT)

Answer 1

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.

Question 2

contrast studies

Answer 2

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

Question 3

gamma camera

Answer 3

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

Question 4

gamma rays

Answer 4

High-energy rays emitted by radioactive substances in tracer studies.

Question 5

half-life

Answer 5

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

Question 6

interventional radiology

Answer 6

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.

Question 7

in vitro

Answer 7

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

Question 8

in vivo

Answer 8

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

Question 9

ionization

Answer 9

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

Question 10

magnetic resonance imaging (MRI)

Answer 10

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

Question 11

nuclear medicine

Answer 11

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

Question 12

positron emission tomography (PET)

Answer 12

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.

Question 13

radioimmunoassay

Answer 13

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

Question 14

radioisotope

Answer 14

Radioactive form of an element substance; radionuclide.

Question 15

radiolabeled compound

Answer 15

Radiopharmaceutical; used in nuclear medicine studies.

Question 16

radiology

Answer 16

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.

Question 17

radiolucent

Answer 17

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

Question 18

radionuclide

Answer 18

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

Question 19

radiopaque

Answer 19

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

Question 20

radiopharmaceutical

Answer 20

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).

Question 21

scan

Answer 21

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

Question 22

scintigraphy

Answer 22

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

Question 23

singe photon emission computed tomography (SPECT)

Answer 23

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

Question 24

tagging

Answer 24

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

Question 25

tracer studies

Answer 25

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

Question 26

ultrasonography (US, U/S)

Answer 26

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

Question 27

ultrasound transducer

Answer 27

Handheld device that sends and receives ultrasound signals.

Question 28

uptake

Answer 28

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

Question 29

ventilation-perfusion studies

Answer 29

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