Diagnostic Ultrasound - Abdomen and Pelvis

Periportal Lesion
892
Differential Diagnoses: Liver
DIFFERENTIAL DIAGNOSIS
Common
• Ascending Cholangitis
• Cavernous Transformation of Portal Vein
• Portosystemic Collaterals
• Hepatic Trauma
• Acute Viral Hepatitis
• Fatty Sparing, Liver
• Diffuse/Infiltrative Hepatic Lymphoma
• Pneumobilia
• Choledocholithiasis
• Metastases
Less Common
• Peribiliary Cyst
• Hepatic Schistosomiasis
• Recurrent Pyogenic Cholangitis
• Iatrogenic Material
• Caroli Disease
• Hepatic Artery Calcification
• Cystic Duct Remnant
ESSENTIAL INFORMATION
Helpful Clues for Common Diagnoses
• Ascending Cholangitis
○ Periportal hypo- or hyperechogenicity adjacent to dilated
intrahepatic ducts
– Due to periductal edema/inflammation
○ Dilatation of intrahepatic bile ducts
○ Purulent bile/sludge as intraluminal echogenic material
in dilated ducts
○ Circumferential thickening of bile duct wall
○ Obstructing stone in common bile duct
• Cavernous Transformation of Portal Vein
○ Collateralization due to portal vein occlusion
○ Usually in subacute or chronic portal vein obstruction
○ Serpiginous tubular channels along expected course of
portal vein
○ Color Doppler shows hepatopetal flow
○ Signs of portal vein occlusion
– Acute: Enlarged portal vein
– Chronic: Small/imperceptible portal vein
– Color Doppler: Lack of flow in portal vein
• Portosystemic Collaterals
○ Serpiginous hypoechoic channels in or around portal
triad
○ Location
– Intrahepatic: Portal to portal veins, portal to hepatic
veins, portal to systemic veins
– Paraumbilical vein (recanalization)
– Gastroesophageal: Coronary and right gastric, left
gastric and splenogastric
– Lienorenal/mesenteric/retroperitoneal
○ Color Doppler
– Shows hepatofugal flow in vessels (opposite to
cavernous transformation)
– Extent of collaterals
○ Background changes of cirrhosis/portal
hypertension/portal vein thrombosis
• Hepatic Trauma
○ Lesions are commonly located in segments 6, 7, 8
○ Echogenicity evolves over time
– Initially echogenic
– Becomes hypoechoic after 4-5 days
– Internal echoes with septa may develop after 1-4
weeks
○ Hematoma tracking along portal triad
– Linear, focal, or diffuse periportal lesion
○ Ancillary signs of trauma
– Subcapsular hematoma; hemoperitoneum, renal, or
splenic laceration/hematoma
○ Better evaluated by MDCT
• Acute Viral Hepatitis
○ Increased echogenicity of fat in periportal tissues,
ligamentum venosum, and falciform ligament
○ Hepatomegaly with diffuse decrease in echogenicity
○ "Starry sky" appearance
– Increased echogenicity of portal triad walls against
background of hypoechoic liver
○ Periportal hypo-/anechoic area
– Due to hydropic swelling of hepatocytes
• Fatty Sparing, Liver
○ Focal hypoechoic area within otherwise echogenic liver
○ No mass effect: Vessels run undisplaced through lesion
○ Due to direct drainage of hepatic blood into systemic
circulation
○ Typical location
– Next to gallbladder: Drained by cystic vein
– Segment 4/anterior to portal bifurcation: Drained by
aberrant gastric vein
• Diffuse/Infiltrative Hepatic Lymphoma
○ Subcentimeter periportal hypoechoic foci, miliary in
pattern
○ Other evidence of lymphoma
– Lymphadenopathy, splenomegaly/splenic lesions,
bowel wall thickening, ascites
• Pneumobilia
○ Highly echogenic linear foci in portal triad
○ Rises to nondependent portion of liver (left lobe if
patient lying supine)
○ Change in position of gas with change in patient position
○ Posterior acoustic shadowing
○ Reverberation artifact deep to lesion
○ Causes
– Recent passage of stone from or instrumentation of
biliary tree
– Choledochoenteric fistula
– Biliary infection by gas-forming organism
• Choledocholithiasis
○ Multiple echogenic foci along portal triad
○ Posterior acoustic shadowing
– Small (< 5 mm) or soft pigmented stones may not
produce posterior shadowing
○ Large stones may cause biliary obstruction, resulting in
focal bile duct dilatation
• Metastases
○ May be located anywhere in liver
○ Usually multiple