Diagnostic ultrasound ( PDFDrive )

100 PART II Abdominal and Pelvic Sonography
A
B
FIG. 4.34 Metastasis to the Portal Vein From Colon Cancer. (A) Sagittal view of the main portal vein at the porta hepatis and (B) subcostal
oblique sonogram of the left ascending branch of the portal vein show the portal vein is distended and highly echogenic (arrows). There is also
evidence of cavernous transformation, an uncommon accompaniment of malignant portal vein occlusion.
A
B
FIG. 4.35 Acute Budd-Chiari Syndrome. (A) Transverse view of liver shows a large, bulbous caudate lobe. (B) Sagittal view of right hepatic
vein shows echoes within the vein lumen consistent with thrombosis, with absence of the vessel toward the inferior vena cava. Doppler ultrasound
showed no low in this vessel.
spared in Budd-Chiari syndrome because the emissary veins
drain directly into the IVC at a lower level than the involved
main hepatic veins. Increased blood low through the caudate
lobe leads to relative caudate enlargement.
Real-time scanning allows the radiologist to evaluate the IVC
and hepatic veins noninvasively. Sonographic features include
evidence of the hepatic vein occlusion (Fig. 4.35B and Fig. 4.36)
and the development of abnormal intrahepatic collaterals (Fig.
4.37). he extent of hepatic venous involvement in Budd-Chiari
syndrome includes partial or complete inability to see the hepatic
veins, stenosis with proximal dilation, intraluminal echogenicity,
thickened walls, thrombosis (Figs. 4.38 and 4.39), and extensive
intrahepatic collaterals 107,108 (see Fig. 4.37). Membranous “webs”
may be identiied as echogenic or focal obliterations of the
lumen. 107 Real-time ultrasonography, however, underestimates
the presence of thrombosis and webs and may be inconclusive
in a cirrhotic patient with hepatic veins that are diicult to
image. 108 Intrahepatic collaterals, on gray-scale images, show as