Medical Terminology Simplified

Radiographic procedure that produces images of an organ or area of the body by in-

troducing a radionuclide substance (tracer or radiopharmaceutical) that releases a low

level of radiation; also called nuclear scanning, radionuclide imaging, and nuclear

medicine scan (See Fig. 2–7C.)

Nuclear scan uses a very small amount of radioactivity and is not known to cause harm.

Any of several radiographic procedures in which specialized machines produce a film

representing a detailed cross section, or slice (cut),of an area, tissue, or organ

Tomography is a valuable diagnostic tool for identifying space-occupying lesions,

such as those found in the liver, brain, pancreas, and gallbladder. Types of tomography

include computed tomography (See Fig. 2–8), positron emission tomography

(See Fig. 2–7F), and single-photon emission computed tomography (SPECT).

Tomography in which a narrow beam of x-rays rotates in a full arc around the pa-

tient to acquire multiple views of the body, which a computer interprets to produce

cross-sectional images of an internal organ or tissue; also called computerized axial

tomography (CAT) scanning

CT scans help detect tumor masses, accumulations of fluid, and bone displacements.

CT scans may be performed with or without a contrast medium. (See Figs. 2–7D

and 2–8).

Radiographic procedure in which a small transducer passed over the skin trans-

mits high-frequency sound waves (ultrasound) that bounce off body tissues

and are then recorded to produce an image of an internal organ or tissue

(See Fig. 2–9.)

In contrast to other imaging techniques, US does not use ionizing radiation (x-ray).

It is used to evaluate fetal development; examine internal structures of the abdomen,

brain, and heart; diagnose musculoskeletal disorders; and evaluate blood flow.

(See Fig. 2–7B.) The record produced by US is called a sonogram or echogram.

Additional Medical Terms • CHAPTER 2 53

nuclear scan

NŪ-klē-ăr

ultrasonography (US)

ŭl-tră-sŏn-ŎG-ră-fē

ultra-: excess, beyond

son/o: sound

-graphy: process of

recording

tomography

tō-MŎG-ră-fē

tom/o: to cut, slice

-graphy: process of

recording

computed tomography

(CT)

cŏm-PŪ-tĕd

tō-MŎG-ră-fē

tom/o: to cut

-graphy: process of

recording

AB

Figure 2-8Computed tomography (CT) scan. with

motorized table (A)and computer (B).