Diagnostic ultrasound ( PDFDrive )

CHAPTER 8 The Gastrointestinal Tract 287
FIG. 8.34 Crohn Appendicitis. (A) Transverse sonogram
in the right lower quadrant shows a thick-walled loop of gut
surrounded by inlamed fat. (B) Cross-sectional and (C) long-axis
high-frequency linear images of this loop of gut show that it is
blind ended. There is massive mural thickening and hyperemia. The
luminal surfaces are in apposition. All changes resolved completely
with conservative management. (With permission from Wilson
SR. The bowel wall looks thickened: what does that mean? In:
Cooperberg PL, editor. RSNA categorical course syllabus. Chicago:
RSNA; 2002. pp. 219-228. 1 )
A
B
C
On sonography, acute diverticulitis is associated with inlammation
of the pericolonic fat. he diverticula may be located in
the cecum or the adjacent ascending colon. When inlamed,
they may have one of two appearances. 62 Most oten, the diverticulum
may show as a pouch or saclike structure arising from
the colonic wall 63 (Fig. 8.35). Wall layers are continued into the
wall of the congenital diverticulum. Hyperemia of the diverticulum
and the inlamed fat is typical. If a fecalith is present within the
diverticulum, it may show as a bright, echogenic focus located
within or beyond a segment of thickened colonic wall. Occasionally,
the culprit diverticulum is not evident and the only observations
are those of inlamed fat and focal thickening of the colonic
wall. In the appropriate clinical milieu, this is highly suspicious
for acute diverticulitis. Treatment of acute diverticulitis is
conservative and not surgical, emphasizing the importance of
preoperative imaging in patients with RLQ pain attributed to
this condition.
Acute Typhlitis
Immunocompromised patients are most oten afected with acute
typhlitis. Although infrequent today in North America, AIDS
patients previously accounted for the overwhelming majority of
cases of acute typhlitis seen since 1990. Cytomegalovirus (CMV)
and Cryptosporidium are the pathogens isolated most oten in