Diagnostic ultrasound ( PDFDrive )

CHAPTER 8 The Gastrointestinal Tract 285
A
B
FIG. 8.31 Normal Appendix. (A) Long-axis image and (B) cross-sectional image show the normal appendix (A) arising from the base of the
cecum (C). The appendix shows a gut signature, a blind end, and measures 6 mm or less in diameter. See also Video 8.13.
A
B
FIG. 8.32 Value of Transvaginal Sonography for Diagnosis of Acute Appendicitis. (A) Long-axis view of the appendix on transvaginal
sonography was the only view to show the blind-ended tip of the luid-distended appendix. (B) Appendix is a large, luid-illed, thick-walled structure
and shows a shadowing appendicolith.
Sonography of Appendiceal Perforation
Loculated pericecal luid
Phlegmon
Abscess
Prominent pericecal fat
Circumferential loss of submucosal layer of the appendix
its occurrence include loculated pericecal luid, phlegmon or
abscess, prominent pericecal or periappendiceal fat, and circumferential
loss of the submucosal layer of the appendix 58 (Fig.
8.33, Video 8.14). False-positive diagnosis for acute appendicitis
may occur if a normal appendix or a thickened terminal ileum
is mistaken for an inlamed appendix.
Crohn Appendicitis
Patients with Crohn disease may have acute appendicitis caused
by IBD involvement of the appendix, in contrast to acute suppurative
appendicitis. he wall of the appendix typically is
extremely thickened and hyperemic with wall layer preservation,
and the luminal surfaces are oten in apposition 59 (Fig. 8.34).
his appearance contrasts with that in suppurative appendicitis,
where luminal distention is the expectation and wall thickening
is moderate at best.
Crohn appendicitis is a self-limited process, 60,61 and treatment
may be conservative if the appropriate diagnosis can be established
with noninvasive techniques. In a small number of the patients
for whom we have suggested this diagnosis, follow-up sonograms
have shown resolution of the sonographic indings with no disease
progression. Patients with Crohn disease who present with Crohn
appendicitis account for about 10% of total presentations. his
patient population typically has a more benign course. If the
appendix is removed surgically in the mistaken belief that the
patient has acute suppurative appendicitis, recurrence or progression
of Crohn disease is rare.
Right-Sided Diverticulitis
Acute inlammation of a right-sided diverticulum is distinct from
the more common diverticulitis that is encountered in the let
hemicolon. hese diverticula occur more oten in women than
in men and have a predilection for Asian populations. Most
patients are young adults. Right-sided diverticula are usually
solitary and are congenital in origin. hey are true diverticula
and therefore have all layers of the gut wall. heir inlammation
is associated with RLQ pain, tenderness, and leukocytosis, with
a mistaken diagnosis of appendicitis in virtually all cases.