Diagnostic ultrasound ( PDFDrive )

CHAPTER 51 The Pediatric Liver and Spleen 1759
A
B
C
FIG. 51.29 Splenic Varices and Splenorenal Shunt. (A)
Splenic varices in a patient with cirrhosis shown on longitudinal
gray-scale image of the left upper quadrant. (B) Color and
pulsed Doppler sonogram shows tortuous veins leaving the
spleen, with largest vessel (blue with Doppler gate) demonstrating
venous low toward the left kidney. (C) Color Doppler
image of this spontaneous splenorenal shunt shows low away
from the spleen toward the kidney.
autosomal recessive polycystic kidney disease. 78 he dilation
of renal collecting ducts in these children is variable and less
severe than in the neonatal form, and renal impairment is less
marked. However, renal architecture is greatly disturbed. he
pyramids are hyperechoic and may contain calcium; small cysts
may be seen; and the kidneys are usually enlarged. hese features
enable informed sonographers to ind the cause of upper intestinal
bleeding in these children during their irst abdominal
sonogram.
Intrahepatic Portal Hypertension
Serious insult to the hepatocyte results in necrosis. Unless necrosis
is overwhelming, scarring and the formation of multiple regenerating
nodules follow. he process of cirrhosis results in scarred
and obstructed sinusoids and abnormal portal venous blood
low through the regenerated nodules. In children, cirrhosis may
result from the following:
• Hepatitis
• Destruction of the hepatocyte by toxins accumulated in
inherited metabolic diseases, such as tyrosinemia, some forms
of glycogen storage disease, and Wilson disease
• Bile stasis, as in biliary atresia and cystic ibrosis
Although diferent types of cirrhosis cause initial obstruction
at presinusoidal (schistosomiasis, biliary cirrhosis), sinusoidal
(Laennec cirrhosis), and postsinusoidal levels, progressive scarring
usually spreads to the entire sinusoid. As intrahepatic portal
venous low stagnates, portosystemic collaterals open. Portal
blood low decreases. Total hepatic blood supply is usually
maintained by an increase of blood low in the hepatic artery.