Other films may include the following.
PA prone projection using an 8 x 10-inch film and a tightly restricted
(b) LAO using a tightly restricted cone field (6 inches) and an 8 to
10-inch film. This radiograph may be done with the patient recumbent (figure 2-22) or
erect. This position tends to displace the transverse processes of the vertebrae away
from the gallbladder. The body is rotated 20 to 30. The degree of body rotation
necessary for optimum demonstration of the gallbladder varies according to body
habitus and position; for example, thin subjects generally require greater rotation than
stout subjects. Varying degrees of rotation may be necessary to differentiate gallstones
from kidney stones or calcified bodies in the mesenteric structure.
(c) Right lateral projection with the patient in the recumbent position,
utilizing an 8 by 10-inch film and a restricted cone field.
(d) PA projection with the patient on his right side (Kirklin) using an 8
by 10-inch film, restricted cone field, and vertical Bucky diaphragm or grid-cassette.
(e) RPO (right posterior oblique) using an 8-inch x 10-inch film and a
restricted cone field. This radiograph may also be done with the patient in either the
recumbent or erect position.
(6) Radiography of the gallbladder with the patient in the erect position may
be done by the using essentially the same relationships with reference to part, film
plane, and alignment of the CR. The erect position will cause the bile laden with
cholecystopaque to stratify into fluid levels according to the degree of concentration and
relative specific gravity. The gallstones, which are lighter than certain layers of the bile,
will float and, upon floating together, form a "density layer" which renders them
radiographically demonstrable. Small, but heavier-than-bile, stones will tend to gravitate
to, and collect in, the fundus portion of the gallbladder. In addition, the gallbladder
tends to shift downward, backward, and towards the midline. Therefore, when the
patient is first x-rayed in the recumbent position and then in the erect position, some
modification of the CR alignment is necessary for the latter position (approximately 1 1/2
to 2 1/2 inches lower).