Diagnostic ultrasound ( PDFDrive )

92 PART II Abdominal and Pelvic Sonography
A
B
C
D E F
G
H
I
FIG. 4.26 Diffuse Fat: Spectrum of Appearances. Mild fatty iniltration: (A) sagittal right lobe, (B) transverse right lobe, (C) sagittal left lobe.
The liver is diffusely bright and echogenic; sound penetration remains good. Marked fatty iniltration: (D) sagittal right lobe, (E) subcostal oblique
view. The liver is enlarged and attenuating, sound penetration is poor, and the walls of the hepatic veins are not deined. Focal fatty sparing: (F)
mimicking a hypoechoic mass; normal liver on biopsy and follow-up. (G) Sagittal and (H) transverse images show focal fatty sparing of the caudate
lobe. (I) Geographic fatty sparing of the entire left lobe marginated by the middle hepatic vein.
CEUS, MRI, or nuclear medicine scintigraphy will avoid
the necessity for biopsy in most patients with focal fatty
alteration.
Glycogen Storage Disease (Glycogenosis)
Von Gierke irst recognized glycogen storage disease (GSD)
afecting the kidneys and liver in 1929. 62 Type 1 GSD (von Gierke
disease, glucose 6-phosphatase deiciency) is manifested in the
neonatal period by hepatomegaly, nephromegaly, and hypoglycemic
convulsions. Because of the enzyme deiciency, large
quantities of glycogen are deposited in the hepatocytes and
proximal convoluted tubules of the kidney. With dietary management
and supportive therapy, more patients currently survive
to childhood and young adulthood. As a result, several patients
have developed benign adenomas or, less oten, HCC. 63
Sonographically, type 1 GSD appears indistinguishable from
other causes of difuse fatty iniltration. Secondary hepatic
adenomas are well-demarcated, solid masses of variable echogenicity.
Malignant transformation can be recognized by rapid
growth of the lesions, which may become more poorly deined. 63
Cirrhosis
he World Health Organization (WHO) deines cirrhosis as a
difuse process characterized by ibrosis and the conversion of
normal liver architecture into structurally abnormal nodules. 64
hree major pathologic mechanisms combine to create cirrhosis:
cell death, ibrosis, and regeneration. Cirrhosis has been classiied
as micronodular, in which nodules are 0.1 to 1 cm in
diameter, and macronodular, characterized by nodules of varying
size, up to 5 cm in diameter. Alcohol consumption is the most