Diagnostic ultrasound ( PDFDrive )

90 PART II Abdominal and Pelvic Sonography
A
B
C
D E F
G
H
I
FIG. 4.24 Hydatid Liver Disease: Spectrum of Appearances. (A) Classic appearance showing a cyst containing multiple daughter cysts.
(B) Sonogram and (C) conirmatory CT scan show a unilocular and simple cyst, a fairly uncommon morphology for hydatid disease. (D) Sonogram
shows a complex mass. Anteriorly, multiple ringlike structures suggest hydatid disease. At surgery, cystic mass showed thick debris and innumerable
scolices. (E) Sonogram and (F) conirmatory CT scan show an indeterminate mass with a thin rim of calciication. (G) Complex mass similar to
that seen in D. There are ingerlike projections within, again suggestive of hydatid disease. (H) Sonogram and (I) conirmatory CT scan show a
central liver mass with rim and internal punctate calciication.
rare. Ultrasound has been used to monitor the course of medical
therapy in patients with abdominal hydatid disease. 42 A reappearance
or persistence of luid within the cavity may signify
inadequate therapy and viability of the parasites. 43
Hepatic alveolar echinococcus is a rare parasitic infestation
by the larvae of E. multilocularis. he fox is the main host. he
sonographic features include echogenic lesions, which may be
single or multiple; necrotic, irregular lesions without a well-deined
wall; clusters of calciication within lesions; and dilated bile ducts. 44
Schistosomiasis
Schistosomiasis is one of the most common parasitic infections
in humans, estimated to afect 200 million people worldwide.
Hepatic schistosomiasis is caused by Schistosoma mansoni, S.
japonicum, S. mekongi, and S. intercalatum. Hepatic involvement
by S. mansoni is particularly severe. S. mansoni is prevalent in
Africa, including Egypt, and South America, particularly in
Venezuela and Brazil. he ova reach the liver through the portal
vein and incite a chronic granulomatous reaction, irst described
by Symmers in 1904 as “clay-pipestem ibrosis.” 45 he terminal
portal vein branches become occluded, leading to presinusoidal
portal hypertension, splenomegaly, varices, and ascites.
he sonographic features of schistosomiasis are widened
echogenic portal tracts, sometimes reaching a thickness of
2 cm. 46,47 he porta hepatis is the region most oten afected.
Initially the liver size is enlarged. As the periportal ibrosis
progresses, however, the liver becomes contracted, and the features
of portal hypertension prevail.