Some internal organs—such as kidneys, blood vessels and the organs
of the gastrointestinal tract—can best be visualized on X-ray film
when the patient ingests a contrast material. This blocks nearly all photons
and makes tissues in which the contrast is distributed appear bright white.
The contrast medium may be given orally, intravenously or rectally, depending
upon the area to be studied.
Fluoroscopy: Fluoroscopy is a type of X-ray that captures moving images,
allowing the radiologist to observe the functioning as well as the anatomy
of internal organs. Common exams that use fluoroscopy include upper gastrointestinal
exams (UGI), barium enemas (BE) and swallowing studies. It also is used
to quickly guide the radiologist when performing a procedure that involves
placing a tube, catheter or other device internally. Examples of such
use include angiography, myelograms and interventional radiology procedures.
For nearly all of these exams, static or still images also are taken to
document what is seen or done at the time of the exam. A fluoroscopy unit
consists of three components: the fluoroscope, which moves over the body
part of interest; the monitor that displays the moving image; and the
X-ray tube that generates the X-rays that pass through the body and create
the image on the fluoroscope. As with any X-ray, you do not feel any sensations
from fluoroscopy itself.