Q4 - Liver (Week 2)

Liver Study Questions

/

/

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)

Page 2

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)

Page 3

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

Page 4

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

Page 5

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

Page 6

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

Page 7

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

Page 8

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

Page 9

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)

Page 10

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

Page 11

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

Page 12

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

Page 13

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

Page 14

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

Page 15

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

Page 16

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

Page 17

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

Page 18

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

Page 19

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

Page 20

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

Page 21

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.