Q4 - Liver (Week 2)

Liver Study Questions

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Winter Appearance of Liver Cyst

• Thin-walled and Anechoic

• Posterior enhancement indicates simple cysts (no septations) versus complex cysts (abscesses, hematomas, trauma)

• Procedures: Aspiration, excision, or ablation can be performed

• US Role:

  • Identify cyst

  • Determine location (which lobe/segment)

Polycystic Liver Disease (PLD)

• A dominant genetic disorder resulting in multiple 2-3 cm cysts

• 60% likelihood of having polycystic renal disease (PRD) - but no two-way correlation

• Cysts in porta hepatis may cause obstruction

• Differential diagnosis includes abscess; labs should be correlated

• PLD is independent, but PRD can cause PLD; PLD cannot cause PRD

Biliary Hamartoma

• Benign liver malformation, disorganized clusters of dilated bile ducts

• Surrounded by connective tissue and fibrous stroma

• Also known as Von Meyenburg complex

• Associated with hepatic fibrosis (too much scar tissue from chronic injury)

• Mimics appearance of liver metastases

Infections Commonly Occurring in Liver (Bacterial Diseases)

• Pyogenic Liver Abscess: Bacterial pus collection; 50% cause unknown

• Amebic Liver Abscess: Caused by parasites

• Viral Hepatitis: Inflammation of the liver due to virus

• Hydatid Disease: Cysts in the liver caused by tapeworm (Echinococcus)

• Types of pathogens: virus (tiny robbers), bacteria (single-celled, may be good or bad), fungi (plant-like), and parasites (hitchhikers)

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Bacterial Travel to the Liver

• Common routes include:

  • Biliary tract (cholangitis & cholecystitis)

  • Portal venous (from diverticulitis or appendicitis)

  • Hepatic artery (from osteomyelitis or sub-acute bacterial endocarditis)

• Cholangitis: Inflammation of bile duct

• Cholecystitis: Inflammation of gallbladder

Ultrasound Appearance of Bacterial Abscess/Pyogenic

• Variable appearance;

  • Complex with internal debris or septations

  • Cystic, well-defined, or irregular borders

  • Ranges from echo-free to highly echogenic

  • May appear hypoechoic related to necrosis

  • Fluid-filled interfaces

Candidiasis (Fungal Disease)

• Affects liver as infection spreads to other organs

• Clinical presentation includes persistent fever in neutropenic patients

• US Appearance: “Wheel within wheel” or “bull’s eye target”

Amebiasis

• Infection by Entamoeba histolytica via fecal-oral route

• Sonographic Features:

  • Round/oval lesions with non-prominent walls

  • Hypoechoic compared to liver (similar to pyogenic abscess)

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Hydatid Disease

• Caused by Echinococcus granulosus (3-6 cm tapeworm; definitive host: dogs, intermediate host: sheep)

• Transmission via fecal matter containing ova

Sono Appearance of Hydatid Disease

• Simple cysts

• Cysts with detached endocyst due to rupture

• Cysts with daughter cysts

• Densely calcified masses

Schistosomiasis

• Most common human parasitic infection

• Causes peri-portal fibrosis and enlarged portal veins

• Clinical features include:

  • Initially hepatomegaly, later contraction with portal hypertension

• Sonographic Appearance:

  • Periportal fibrosis and calcification

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Pneumocystis Carinii

• Most common organism causing opportunistic infection in AIDS patients

• Affects patients with bone marrow issues, organ transplants, or who are on chemotherapy

• Opportunistic infection: Can cause serious complications due to weakened immune system

Diffuse Hepatocellular Disease

• Affects hepatocytes and impacts liver function

• Measured via liver function tests, specifically ALT levels

Hepatocellular Disease

• Damages hepatocytes, affecting liver enzyme function

• Causes include infections, drugs, toxic chemicals, alcohol abuse, and obesity

Subcategories of Diffuse Liver Disease

• Fatty infiltration

• Acute and chronic hepatitis

• Early alcoholic liver disease

• Acute and chronic cirrhosis

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Causes of Hepatitis

• Viral infections

• Drugs and alcohol

• Metabolic conditions (e.g., diabetes)

• Autoimmune disorders

Types of Viral Hepatitis

• Transmission routes include fecal-oral, blood products, sexual contact, and transfusions

• Types include Non-A, Non-B, and NANB hepatitis

Hepatitis Abnormal Lab Values

• Elevated liver function tests (LFTs): ALT, AST, Bilirubin

• Increased WBC count

• Presence of viral antibodies

Ultrasound Role in Hepatitis Evaluation

• Assess for parenchymal changes

• Determine presence of hepatomegaly

• Rule out biliary obstruction

• Establish baseline liver and spleen size

Acute Hepatitis Sonographic Features

• General parenchymal changes

• Decreased echogenicity with accentuated brightness in portal triads

• Gallbladder wall thickening

• Possible edema

Common Causes of Fatty Liver

• Primarily obesity

• Other causes:

  • Alcoholic liver disease

  • Diabetes

  • Chronic illnesses

  • Steroid use

  • Pregnancy

Grading Degree of Fatty Infiltration

• Normal

• Grade 1: Mild; portal veins still visible

• Grade 2: Moderate; portal veins not visible

• Grade 3: Severe; significant attenuation with minimal portal vein visibility

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Focal Fatty Infiltration

• Normal liver tissue mixed with fatty tissue

• Can mimic mass lesions

Cirrhosis

• Chronic damage leading to degradation of liver architecture

• Liver function diminishes, potentially leading to failure

• Causes include:

  • Alcohol

  • Chronic hepatitis

  • Drugs

  • Biliary obstruction

  • Cardiac diseases

  • Metabolic/storage diseases

Cirrhosis Clinical Presentation

• Symptoms include jaundice, hepatomegaly, and ascites

Cirrhosis Ultrasound Appearance

• Variable based on disease stage;

  • Initially large, later small right lobe with prominent caudate and left lobe

  • Coarse echotexture

  • Surface nodularity (often seen with ascites)

  • Loss of intrahepatic vasculature delineation

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Doppler Findings with Cirrhosis

• Decreased amplitude of phasic oscillations

• Narrowed hepatic veins with high-velocity areas and turbulence

Ancillary Findings Associated with Cirrhosis

• Splenomegaly

• Ascites

• Portal vein hypertension and thrombosis

• Collaterals (recanalized umbilical vein)

• Possible development of HCC (hepatocellular carcinoma)

Caudate Lobe

• Couinaud’s Segment I

• Typically spared or hypertrophied in cirrhosis

• Has its own blood supply

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Umbilical Vein and Ligamentum Teres

• Falciform ligament houses umbilical vein, carries maternal blood to fetal liver

• Ligamentum teres is the obliterated umbilical vein remnant

Types of Portal Hypertension

• Intrahepatic: Caused by cirrhosis

• Extrahepatic: Caused by thrombosis of portal or splenic veins

Causes of Extrahepatic Hypertension

• In Children: Thrombosis due to umbilical vein catheterization, omphalitis, or sepsis

• In Adults: Trauma, HCC, or sepsis

Portal Vein Hypertension Secondary Sonographic Findings

• Splenomegaly

• Ascites

• Recanalized umbilical vein

• Porto-systemic venous collaterals

• Reverse flow on Doppler (hepatofugal)

Doppler Role in Portal Hypertension

• Determine direction of flow

• Evaluation challenges for ill patients with ascites or contracted livers

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Collaterals in Portal Vein Hypertension

• Major sites include:

  • Gastroesophageal junction

  • Paraumbilical veins

  • Splenorenal and gastrorenal veins

  • Intestinal-retroperitoneal veins

  • Hemorrhoidal veins

Portal Vein Thrombosis Associations

• Commonly associated with malignancies (e.g., HCC, pancreatic cancer)

Portal Vein Thrombosis Sonographic Findings

• Echogenic thrombus within the portal vein lumen

• Increased diameter of portal vein (>13 mm)

• Presence of collateral channels, indicating alternate pathways due to blockage

Cavernous Transformation of Portal Veins

• Collateral channels develop in chronic portal vein obstruction

• Diagnosed by visualization of extrahepatic portal veins not present

Budd Chiari Syndrome

• Occlusion of some or all hepatic veins and inferior vena cava (IVC)

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Causes of Budd Chiari Syndrome

• Can result from:

  • Chronic leukemia

  • Trauma (e.g., extension from HCC, RCC)

  • Pregnancy

  • Congenital anomalies

  • Coagulation abnormalities

Sonographic Findings for Budd Chiari

• Hepatic vein occlusions

• Enlarged, bulbous liver

• Possible infarcted liver areas

• Ascites presence

• Intrahepatic collateral formations

Purpose of Portal-Systemic Shunt (TIPS)

• Redirects blood flow from collaterals to reduce pressure on hepatic veins and treat varices or refractory ascites

Types of Shunts

• TIPS: Transjugular Intrahepatic Portosystemic Shunt

• Warren Shunt: Distal spleno-renal

• Portal Caval and Mesocaval Shunts

TIPS Procedure

• Typically placed between portal vein and hepatic vein to manage complications of portal hypertension

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Sonographic Evaluation Post-TIPS

• Assess patency of shunt

• Identify stenosis or occlusion

• Determine direction of flow in stent

• Evaluate flow direction in portal and hepatic veins

TIPS Doppler Findings

• PSV (Peak Systolic Velocity) between 135-200 cm/sec

• Potentially turbulent flow

• Hepatofugal flow patterns in right/left portal veins (abnormal)

Abnormal Ultrasound Findings with Shunt Malfunction

• No flow indicates possible thrombus or occlusion

• PSV <90 cm/sec or >200 cm/sec indicates critical issues

• Changes in velocity by >50 cm/sec may indicate a problem

Most Common Benign Liver Lesions and Neoplasms

• Cavernous hemangioma (most common)

• Focal nodular hyperplasia (FNH)

• Lipoma

• Angiomyolipoma

• Often asymptomatic

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Cavernous Hemangioma

• Most common benign liver lesion

• More prevalent in women (5:1 ratio)

• Sonographic Appearance:

  • Small (<3 cm), well-defined, homogeneous, hyperechoic, extremely slow blood flow

Focal Nodular Hyperplasia (FNH)

• Second most common benign liver mass

• Hormonal stimulation may be a contributing factor

• Generally asymptomatic

• Sonographic Appearance:

  • Solitary with central scar

  • Majority <5 cm

  • May displace normal vessels

  • Useful Doppler assessment for vessels

  • More common in women in childbearing years

Hepatic Adenoma

• Associated with oral contraceptives and glycogen storage diseases

• Symptoms can range from asymptomatic to RUQ pain

• Similar US appearance to FNH but less common

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Hepatic Adenoma Sonographic Appearance

• Varies in size and composition

• Can present as round/oval, well-defined borders, homogeneous, and echogenic

Hepatic Lipoma

• Rare benign mass, isolated and asymptomatic

• Sonographic Appearance:

  • Well-defined, echogenic; CT shows fatty nature

Hepatocellular Carcinoma (HCC)

• Most common primary malignant liver tumor

• Strongly associated with cirrhosis (especially in the USA)

• Increased levels of alpha-fetoprotein (AFP)

• Clinical Factors:

  • 50-60% of cirrhotic patients develop HCC

  • Often solitary, multiple, or diffuse

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Clinical Findings of HCC

• Later stages present with:

  • Elevated AFP levels

  • RUQ pain

  • Weight loss

  • Ascites

• Laboratory values confirmed presence of AFP

Hepatoblastoma

• Most common primary liver tumor in children

• Associated with Beckwith-Weidemann syndrome and hemihypertrophy

• Sonographic Appearance:

  • Single, large solid mass with mixed echogenicity

Metastatic Liver Disease (METS)

• 18-20 times more common than primary liver tumors

• Detection significantly alters prognosis

• 25-30% of liver cancer patients also have metastatic disease

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Primary Tumor Sites Leading to Liver Mets

• Colon

• Stomach

• Pancreas

• Breast

• Lung

• Gallbladder

Ultrasound Patterns Associated with Liver Metastases

• Hyperechogenic = Hepatocellular carcinoma (HCC)

• Hypoechoic = breast, lung cancers, lymphoma

• Target or bull's-eye = often seen with lung cancer

• Mixed or cystic lesions = may indicate complex pathology

Liver Trauma

• Can involve hematoma, lacerations, free fluid, contusions, active bleeding, or ruptured capsule

• Most common site affected is the posterior segment of the right lobe

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Liver Transplantation

• Most frequent indications:

  • Hepatitis C

  • Alcoholic liver disease/cirrhosis (post-recovery)

  • Biliary cirrhosis

  • Sclerosing cholangitis

• Contraindications for Liver Transplantation:

  • Compensated cirrhosis

  • Extrahepatic malignancy

  • Cholangiocarcinoma

  • Active untreated sepsis

  • Advanced cardiopulmonary disease

  • Active alcoholism/substance abuse

  • Anatomical abnormalities

Anastomosis Sites in Liver Transplantation

• Hepatic Artery: Anastomosis occurs between donor's and recipient's blood vessels

• Portal Vein: End-to-end connection between donor and recipient

• IVC: End-to-end connections above and below the liver

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Liver Transplant Complications

• Biliary complications:

  • Stricture

  • Thrombosis

  • Sclerosing cholangitis

• Hepatic artery complications:

  • Stenosis, thrombosis

• Portal vein complications:

  • Stenosis or thrombus formation

• Collections:

  • Abscess vs. infarct

  • Ascites

Spectral Doppler Abnormality in Severe Narrowing of Hepatic Artery

• Tardus Parvus: Aliasing with high peak, distorted waveforms

  • Can lead to ischemia of the liver due to reduced blood supply

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Outcomes and Observations from Liver Take Home Quiz

1. Right hepatic vein divides the right lobe into segments

2. Reidel’s lobe: A tongue-like projection of the right lobe

3. Patent umbilical vein found in the left lobe of the liver

4. Useful liver lab values: AST, ALT

5. Caudate lobe (Couinaud’s Segment I) has its own blood supply

6. Left lobe segment landmarks: Segment I (caudate), II (superior lateral), III (inferior lateral), IVa (superior medial), IVb (inferior medial)

7. Right lobe segment landmarks: Segment V (inferior anterior), VI (inferior posterior), VII (superior posterior), VIII (superior anterior)

8. Landmarks dividing the right and left lobes seen on ultrasound: Middle hepatic vein, imaginary line from gallbladder to IVC

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Additional Landmarks from Ultrasound and Quiz Responses

• Three landmarks for left lobe segmentation:

  • Left hepatic vein

  • Left portal vein

  • Ligamentum teres

• Landmarks showing caudate lobe area:

  • Anterior (ligamentum venosum)

  • Posterior (IVC)

  • Inferior (porta hepatitis)

Common Causes of Hepatitis

• Alcohol

• Drugs

• Ischemia

• Viral infections

Important Lab Values for Liver Disease Evaluation

• ALT

• AST

• Bilirubin

Fungal Liver Disease Appearance

• Candidiasis appears as a “wheel within a wheel” on ultrasound.

Liver Disease Processes with Cysts and Daughter Cysts

• Hydatid disease

Opportunistic Infection in AIDS

• Pneumocystis carinii

Most Common Cause of Fatty Liver Disease

• Obesity

Causes of Cirrhosis

• Alcohol

• Drugs

• Hepatitis

• Biliary obstruction

• Cardiac/metabolic diseases

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Compensatory Changes in Cirrhosis

• Caudate lobe sparing and hypertrophy

Hepatic Vein Appearance with Cirrhosis

• Exhibits narrowing and aliasing

Ancillary Findings Associated with Cirrhosis

• Splenomegaly

• Ascites

• Portal vein hypertension and thrombosis

• Collaterals (including recanalized umbilical vein)

• Possible development of HCC

Common Causes of Intrahepatic Portal Hypertension

• Cirrhosis

Common Causes of Extrahepatic Portal Hypertension

• Portal vein thrombosis

Doppler Findings for Portal Vein Hypertension

• Hepatofugal flow indicated on Doppler studies.

Recanalized Umbilical Vein

• Identified as the ligamentum teres remnant

Congenital Occlusion of Hepatic Veins and IVC

• Known as Budd Chiari Syndrome

TIPS Shunt Placement

• Specifically between the portal vein and the hepatic vein

Ultrasound's Role in TIPS Evaluation

• Assess patency, stenosis, occlusion, and flow direction

Normal Portal Vein Flow in TIPS Patients

• Approximately 135 to 200 cm/sec

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Most Common Benign Liver Tumor and Appearance

• Cavernous hemangioma

  • Appearance: Small, well-defined, homogeneous, hyperechoic, and extremely slow blood flow

Liver Tumor that Demonstrates a Stellate Lesion

• Focal Nodular Hyperplasia (FNH)

Liver Tumor Associated with Oral Contraceptives

• Hepatic adenoma

Most Common Cause of HCC in the Western World

• Cirrhosis

Doppler Appearance of Occluded Hepatic Artery

• Tardus parvus pattern.