Ascites: Fluid in dependent recesses of peritoneal cavity
Splenomegaly: Spleen is enlarged > 500 cc
Varices: Well-defined, tubular or serpentine collateral vessels with same enhancement as adjacent veins
– Usually opacify on venous phase (not arterial phase)
Mesenteric edema: ↑ attenuation of mesenteric fat
Dilation of mesenteric veins : Portal vein > 13 mm
Slow or reversed flow in portal veins on ultrasound
– Slow flow in portal vein (< 15 cm/sec)
– Portal flow may be biphasic or completely reversed
– ↑ risk of portal vein thrombosis
Portal gastropathy, enteropathy, and colopathy
– May manifest as thickening of colon (especially right colon), small bowel, and stomach
Gallbladder wall thickening
PATHOLOGY
• Causes of portal hypertension divided into 3 categories
Pre sinusoidal: Portal vein/splenic vein thrombosis
Sinusoidal: Cirrhosis (most common), extensive hepatic tumor, or any severe hepatocellular disorder
Post sinusoidal: Right-sided heart failure, constrictive pericarditis, Budd-Chiari syndrome
• Varices (portosystemic collaterals) develop when portal pressures increase beyond critical value
Blood in portal venous system bypasses liver and empties into systemic veins via portosystemic collaterals
CLINICAL ISSUES
• Asymptomatic until varices rupture or ascites are infected
• 30% of patients with esophageal varices experience variceal hemorrhage within 2 years of diagnosis
• Many patients with cirrhotic ascites develop spontaneous bacterial (or rarely tuberculous) peritonitis
TERMINOLOGY
Definitions
• Portal hypertension: Elevated portal pressures due to resistance to portal flow, defined as absolute portal venous pressure of > 10 mm Hg or gradient between portal and systemic veins of > 5 mm Hg
• Varices: Abnormally dilated and tortuous veins due to rerouting of blood flow away from liver into lower pressure systemic veins through collateral pathways
• Ascites: Pathologic fluid accumulation in peritoneal cavity
IMAGING
General Features
• Best diagnostic clue
• Location
Ascites: Dependent recesses of peritoneal cavity
• Common features of portal hypertension
Ascites: Water density fluid in dependent recesses of peritoneal cavity
Splenomegaly: Spleen is enlarged > 500 cc
– CT or US can estimate or calculate splenic volume
– Usual upper limits: 13 cm in length and 6 × 8 cm in width and breadth, respectively
Varices: Well-defined, tubular or serpentine portosystemic collateral vessels with same enhancement as adjacent veins
– Usually opacify on venous phase images (not on arterial phase)
Mesenteric edema: Stranding and increased attenuation in mesenteric fat
Dilation of mesenteric veins (portal vein, superior mesenteric vein, and splenic vein)
– Portal vein is often dilated > 13 mm
Slow or reversed flow in portal veins on Doppler ultrasound
– Normal portal vein flow is hepatopetal (toward liver) with normal flow velocity of 15-40 cm/sec
– As portal hypertension progresses, portal blood flow velocities decrease
– Eventually, portal flow may be biphasic (alternating hepatopetal/hepatofugal flow) or completely reversed
– Stasis of blood flow in portal vein as well as hypercoagulability due to intrinsic liver disease increases risk of portal vein thrombosis
Portal gastropathy, enteropathy, and colopathy
– May manifest as thickening of colon (especially right colon), small bowel, and stomach
Gallbladder wall thickening: Due to combination of portal hypertension, hepatocellular dysfunction, and hypoproteinemia
• Varices: Types or locations
Left gastric venous collateral vessels
– Vascular channels in triangular fatty tissue between medial wall of upper gastric body and posterior margin of left hepatic lobe in lesser omentum
– Coronary (left gastric) vein ≥ 5-6 mm in diameter is considered abnormal
– Usually accompanied by esophageal or paraesophageal varices
Esophageal varices
– Dilated tortuous submucosal venous plexus of esophagus can be divided into “uphill” and “downhill” varices
Uphill varices (collateral blood flow into superior vena cava (SVC) from portal vein via azygous vein): Result from portal hypertension and found in distal 1/2 of esophagus
Downhill varices (collateral flow from SVC into inferior vena cava [IVC] or portal system): Usually due to SVC obstruction and found in proximal 1/3 of esophagus
– Tortuous or serpiginous longitudinal filling defects on esophagography
Varices may collapse during esophageal peristalsis or with distention of lumen
Best detected when esophagus is collapsed and esophageal mucosa coated with thick barium
– CECT has limited sensitivity for small esophageal varices, which may not be evident when collapsed
Can be simulated or hidden by esophagitis or hiatal hernia
– Endoscopy is most sensitive diagnostic tool
– Most clinically significant varices due to risk of bleeding
Paraesophageal varices
– Collateral vessels in posterior mediastinum behind esophageal wall connect coronary vein with azygos and hemiazygos veins and vertebral plexus
– Can mimic posterior mediastinal mass on chest x-ray
Recanalized paraumbilical vein
– Dilated collateral vein (≥ 3 mm) arising from left portal vein and coursing between medial and lateral segments of left hepatic lobe in anterior edge of falciform ligament
– Presence is virtually diagnostic of portal hypertension
Abdominal wall varices
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