What are the limitations of cholescintigraphy?
Nonvisualization (the failure of the gallbladder to appear on a
cholescintigraphy scan) of the gallbladder occurs because of disease
of the gallbladder, particularly gallstones. However,
nonvisualization does not necessarily mean that the obstruction is
the cause of the patient's problem. For example, patients with
gallstones often have a nonvisualizing gallbladder due to obstruction
of the cystic duct, but the obstruction causes no symptoms. Thus,
cholescintigraphy is helpful only if the patient's problem is likely-
based on the history and physical examination-to be due to disease of
the gallbladder or bile ducts.
With the use of cholecystokinin, poor contraction of the gallbladder
can be seen in some normal individuals. Therefore, reduced
contraction does not always mean that the gallbladder is diseased.
Again, cholescintigraphy with cholecystokinin is helpful only if the
patient's problem is likely-based on the history and physical
examination-to be due to disease of the gallbladder or bile ducts.
Another limitation of cholescintigraphy is that this test does not
work when the patient's serum bilirubin is greater than 15-20 mg%.
What are the side effects of cholescintigraphy?
There are few side effects to cholescintigraphy. Reactions to the
radioactive chemical and cholecystokinin are rare. The amount of
radioactivity that patients are exposed to is small. The radioactive
compound is eliminated in the stool, and the radioactivity
deteriorates rapidly within hours.
What alternatives are there to
cholescintigraphy?Last Editorial Review: 4/22/2002
Other common means of evaluating the gallbladder and bile ducts
include ultrasonography and computerized tomography (CT or CAT
scan). Cholangiography, either percutaneous (through the skin) or
endoscopic (ERCP) (inserted down the throat), is a radiological
procedure in which dye is injected into the gallbladder and bile
ducts and then x-rays are taken. Newer procedures include endoscopic
ultrasonography and magnetic resonance imaging (MRI)
cholangiography. Oral cholecystography in which x-rays are taken of
the gallbladder following ingestion of a dye that is concentrated in
the gallbladder, is rarely done.