Diagnostic ultrasound ( PDFDrive )

1738 PART V Pediatric Sonography
A B C
D
E F G
FIG. 51.8 Biliary Atresia Spectrum. (A) Transverse sonogram near the porta hepatis. Triangular cord sign is linear, echogenic ibrous tissue
(arrowhead) anterior to a normal portal vein (PV) and hepatic artery (HA). Failure to visualize the common bile duct in a newborn with jaundice is
strongly suggestive of biliary atresia. (B) Gallbladder ghost triad: small gallbladder (arrows), irregular and incomplete echogenic lining, and indistinct
lobular wall. Highly speciic inding for biliary atresia. (C) to (G) Polysplenia syndrome in a different patient, with preduodenal portal vein and
interruption of inferior vena cava (IVC). (C) Transverse liver sonogram shows aorta (A) anterior and left of the spine in newborn girl. The bifurcation
of the portal vein (arrow) is more anterior than usual. (D) Right transverse sonogram shows liver extending across the entire upper abdomen. IVC
is missing on both views. (E) In left upper quadrant, several small spleens are present. No gallbladder was found in this patient with biliary atresia.
(F) Coronal magnetic resonance spoiled gradient echo (SPGR) images performed for ascites and elevated liver enzymes shows polysplenia. (G)
Transverse liver with anteriorly positioned portal vein several months after Kasai procedure.
bacterial in origin) occur. 22,23 he gallbladder wall may be
thickened, probably from hypoalbuminemia. Dystrophic calciications
in the hepatic parenchyma may be seen.
Neonatal Jaundice and Urinary Tract
Infection or Sepsis
he association of jaundice with urinary tract infection or sepsis
occurs more oten in male than female newborns. Jaundice,
hepatomegaly, and vomiting are common clinical signs. Urinary
tract symptoms are uncommon, as are shock and fever. A thorough
examination of the kidneys, ureters, and bladder should therefore
accompany sonography of the liver in the infant with jaundice.
Similarly, the diaphragm and lung bases should be examined to
look for pleural efusions and pneumonia, which may be accompanied
by sepsis and jaundice in the newborn.
Inborn Errors of Metabolism
Because these disorders cause liver damage in the newborn,
some rapidly destroying the liver if untreated, and because several
can be treated efectively with diet or drugs once diagnosed,
pediatricians and radiologists should be well acquainted with
inborn errors of metabolism. Liver damage is caused by storage
of a hepatotoxic metabolite or by absence of an essential enzyme
that impairs the detoxiication process of the liver.
Steatosis is especially prominent in the glycogen storage
diseases, galactosemia, tyrosinemia, and cystic ibrosis. Cirrhosis
eventually develops in all the diseases that cause liver
damage, and portal hypertension then follows. he risk of
hepatocellular carcinoma is signiicantly increased in α 1 -
antitrypsin deiciency, in tyrosinemia, and in glycogen storage
disease type I. Liver adenomas also develop in the last two
entities, as does renal tubular disease, which is usually characterized
by acidosis and nephrocalcinosis. 16
Tyrosinemia is best treated by transplantation. Until drug
therapy became available for the treatment of the acute neurologic
crises in infants with acute tyrosinemia, transplantation was
performed as a lifesaving procedure as soon as surgically feasible.
Currently, transplantation is done once liver nodules appear
because hepatocellular carcinoma develops in about 30% of
children with tyrosinemia who survive the neonatal period. A
review of livers dissected at liver transplantation found that
preoperative sonograms and computed tomography (CT) scans
were not accurate in distinguishing regeneration nodules, adenomas,
and carcinomas, nor was alpha-fetoprotein (AFP) analysis 24
(Fig. 51.10).