(7) Special methods for radiography of the gallbladder may include the use
of spot-film or tomography.
(a) Spot-filming. Following exposure and processing of the survey film,
the patient is positioned under the fluoroscope, and the radiopaque gallbladder is
localized. Various spot-film exposures may be obtained with the patient in either the
recumbent or the erect position.
(b) Tomography. Though still used, has mostly been replaced with
computerized tomography and ultrasound. After accomplishing the routine survey film,
the radiologist specifies the number of layers or "cuts" to the spot-filmed and also the
level at which each is to be made. By the use of tomographic technique, it is possible to
avoid troublesome gas pockets and loculi or, at least, to lessen their adverse effects.
Also, under certain conditions, gallstones casting doubtful densities when produced by
conventional radiography can be more readily distinguished.
(c) Ultrasound. A preferred method of visualizing the gallbladder is the
ultrasound. This reduces the patient's exposure to ionizing radiation.
(8) The cholecystographic series is usually terminated with the final film
begin taken 1/2 to 1 hour after ingestion of a "fatty meal" that is given to the patient
immediately after satisfactory demonstration of the gallbladder.
b. Intravenous Method.
(1) The preparation of the patient and the radiographic procedure are
essentially the same as for the oral method. The patient is given nothing by mouth the
night before. The difference lies in the contrast medium used, the time at which it is
introduced, and the method of introduction.
(2)
A cholecystopaque, such as cholografin sodium, is injected into the vein
of the arm.
(3) Radiographic examination is made in accordance with established
routine--usually about 4 hours after injection. Additional films may be taken at
subsequent intervals.
(4)
A fatty meal is given to the patient if this has been ordered by the
radiologist.
2-9.
CHOLANGIOGRAPHY
Cholangiography is a procedure for the demonstration of the biliary tract after the
introduction of a contrast medium. The contrast medium may be introduced by either of
two methods: direct and intravenous.
MD0959
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