Diagnostic ultrasound ( PDFDrive )

CHAPTER 8 The Gastrointestinal Tract 267
A
B
FIG. 8.11 Metastatic Malignant Melanoma to Small Bowel. (A) Transverse paraumbilical sonogram shows well-deined, hypoechoic mass
with central irregular echogenicity with gas artifact suggesting gut origin. (B) Conirmatory CT scan.
A
B
FIG. 8.12 Peritoneal Metastases in Two Patients. (A) Transvaginal image shows ascites and visceral peritoneal plaque on the surface of the
small bowel loop (arrows) from metastatic ovarian cancer. (B) Transvaginal scan of peritoneal drop metastasis from stomach primary shows grossly
particulate ascites. There is a small peritoneal implant in the vesicouterine angle.
change except with acute disease. Further, the involved colon is
readily evaluated with colonoscopy and also with all crosssectional
imaging, making its assessment relatively straightforward.
Crohn disease, by comparison, is a chronic transmural. he
peak age of onset is early in life, between the ages of 15 and 40
years, thus afecting patients during their most productive years.
he natural course of the disease includes alternating periods
of active inlammation and remission with a strong tendency to
complicate over time, with the development of penetrating and/
or ibrostenotic lesions. As a result, surgical intervention rates
have been high. Historically, Crohn disease was managed according
to patient symptomatology. It is recognized, however, that
neither inlammatory markers nor symptoms are an accurate
relection of the state of the disease. Today, therefore, there is a
dramatic shit in approach with an efort to treat to the target
of mucosal healing on endoscopy, including the use of aggressive
biologic therapy and the increasing popularity of early introduction
of anti–tumor necrosis factor-α (anti-TNFα). hese management
changes necessitate frequent monitoring of all patients
because repeated endoscopic performance is poorly tolerated,
expensive, and not without risk. herefore safe, objective,
noninvasive, and accurate methods for measuring the severity
of inlammatory activity are vital.
Imaging plays a major role in the diagnosis of disease, 18 in
the detection of recurrence, and in the recognition of complications,
which may be associated with a silent clinical course.
Surveillance imaging and monitoring response to therapy (which
may be both expensive and toxic) is of prime importance. In a
meta-analysis comparing diferent modalities for diagnosis of
IBD, mean sensitivity estimates for the diagnosis on a per-patient