Page 335 - Feline diagnostic imaging

21.3 ­Ultrasosotraphy soflphf raltsoolhaloorU tral 343
intraluminal gas and mucus. A nasogastric tube can be
passed to facilitate its identification. The thoracic esopha-
gus can occasionally be seen as it passes through the esoph-
ageal hiatus of the diaphragm.

21.3.2 Stomach
The wall, contents, and motility should be evaluated. The
appearance varies with the degree of distension and the
contents (Figure 21.11). The serosal surface of the stomach
is hyperechoic while the muscularis propria is hypoechoic.
The submucosa is hyperechoic and extends into the villi.
The mucosa has a variable thickness and is hypoechoic.
When fluid is present in the lumen, the mucosal surface of
Figure 21.10 Barium enema performed in a 4-month-old cat with mucosal luminal interface will appear hyperechoic. This is
atresia ani and obstipation during fluoroscopy. Following resolution not a true layer and is not seen when there is gas or other
of colonic distension, 24 mL of barium sulfate was introduced into hyperechoic material within the lumen. Gas is strongly
the colon through a red rubber catheter (arrows). No additional
congenital anomalies were detected in the colon. Some irregularity reflective, resulting in reverberation artifact, which is often
was attributed to colitis. Source: Courtesy of Dr Adrien-Maxence Hespel. referred to as a “dirty acoustic shadow.” When the stomach

(a) (b)

(c) (d)

Figure 21.11 Ultrasonography of the normal feline stomach. (a) Empty stomach (arrow) of a normal Sphynx cat. The rugal folds give
the stomach a star-shaped appearance. (b) Normal fluid-filled stomach of a 14-year-old cat with pancreatitis. The lumen is anechoic
and wall layers are clearly visualized. Wall thickness is measured between the calipers. The mucosa surface (arrow) of the stomach and
intestines shows as a separate hyperechoic layer when fluid is present in the lumen. (c) Normal stomach of the same Sphynx cat
shown in (a) but on a different day. The near wall is visible but reverberation artifact (arrows) shadows the far wall, preventing it from
being visualized. (d) Food (arrows) is seen in the stomach of another cat.