L4+Liver
Page 1: Liver Overview
Chapter Overview
Chapters 9 & 25 cover liver anatomy, embryology, and function
Page 2: Embryology of the Liver
Development Process
The liver develops from the foregut epithelium of the gastrointestinal tract.
Hepatocyte Origin:
Hepatocytes start from the hepatic diverticulum, which forms from foregut endoderm.
The hepatic diverticulum divides into:
Ventral Portion: Forms the gallbladder.
Liver Primordium: Develops into the liver.
Hematopoiesis: Begins in the liver around the 6th embryonic week and ceases at birth.
Page 3: Normal Anatomy of the Liver - Microanatomy
Structure Composition
Liver parenchyma consists of:
Hepatocytes: Arranged in lobules interspersed with reticuloendothelial cells (Kupffer cells).
Within each lobule:
Hepatocytes are organized in radial cords around a central hepatic venule.
Adjacent arterioles supply blood to the tissue.
Page 4: Normal Anatomy of the Liver - Macroanatomy
Peritoneal Location
The liver is mostly intraperitoneal, with some exceptions:
Gallbladder fossa
Porta hepatis
Bare area (attached directly to the diaphragm)
Location: Posterior surface of the right lobe.
Boundaries: Coronary and triangular ligaments.
Size and Weight
Average adult liver weight: 1200–1600 grams
Approximate dimensions:
Transverse: 20–36 cm
Anterior-Posterior (AP) at midclavicular line: 10.4–21 cm
Cranio-Caudal (CC) at midclavicular line: 7–15.7 cm
Diagnostic Note
Hepatomegaly suspected if craniocaudal length exceeds 16 cm.
Right lobe extending below the right kidney (excluding Riedel’s lobe) may indicate hepatomegaly.
Page 5: Normal Anatomy of the Liver - Sonographic Imaging
Imaging Position
Position of transducer to acquire an image in the right midclavicular line.
Note: Longitudinal position of the probe over the right hypochondrium for correct imaging.
A two-dimensional sonographic image depicts craniocaudal measurement from dome to tip of liver (C-MCL).
Page 6: Glisson’s Capsule
Description
A connective tissue layer enveloping the liver and surrounding portal vessels.
Location: Predominantly in the right hypochondriac region, extending into the epigastrium and possibly to the left midclavicular line.
Page 7: Traditional Lobar Anatomy
Lobes of the Liver
Right Lobe:
Largest lobe, approximately six times larger than the left.
Separated from the left lobe by the falciform ligament.
Contains three fossae on its visceral surface:
Porta hepatis
Gallbladder
Inferior vena cava (IVC)
Left Lobe:
Located to the left of the falciform ligament and proximal left portal vein.
Quadrate Lobe:
Located anterior to the porta hepatis, between the gallbladder fossa and the fissure for the ligamentum teres.
Caudate Lobe:
Lies posterior to the right lobe and porta hepatis; bounded by the ligamentum venosum (anteriorly) and the IVC (posteriorly).
Page 8: Functional Lobar Anatomy
Overview
Divides the liver into three lobes (right, left, caudate) and further segments based on vascular supply and drainage.
Divisional Landmarks
Major Hepatic Veins: Separate lobes (interlobar) and segments (intersegmental).
Portal Veins: Course within segments (intrasegmental), except proximal left portal vein, which is interlobar.
Fissures and Ligaments: Include the main lobar fissure, ligamentum venosum, falciform ligament, ligamentum teres, gallbladder, porta hepatis, IVC.
Page 9: Vascular Supply and Functional Lobar Anatomy
Right Lobe Composition
Includes anterior and posterior segments divided by the right hepatic vein.
Vascular Supply:
Anterior segment: Supplied by the anterior branch of the right portal vein.
Posterior segment: Supplied by the posterior branch of the right portal vein.
Left Lobe Composition:
Subdivided into medial and lateral segments, divided by the left hepatic vein, left portal vein, and ligamentum teres.
Vascular Supply:
Medial segment: Supplied by medial branch of left portal vein.
Lateral segment: Supplied by lateral branch of left portal vein.
Caudate Lobe:
Positioned between the IVC and ligamentum venosum, may extend in a tongue-like projection (caudate process).
Receives blood from both right and left portal veins.
Page 10: Couinaud’s Classification
Overview
A surgically relevant method of segmental localization based on vascular and ligamentous anatomy.
Each liver segment contains at least one central branch of the portal vein, bordered by a hepatic vein.
Page 11: Couinaud’s Classification - Segment I
Segment I (Caudate Lobe)
Description: Left portion, Spiegel’s lobe.
Vascular Supply: Supplied by branches of both the right and left portal veins.
Drainage: Emissary veins drain directly into the inferior vena cava (IVC).
Page 12: Couinaud’s Classification - Segment II
Segment II (Lateral Superior Segment)
Description: Part of the left lobe.
Vascular Supply: Supplied by the ascending branch of the left portal vein.
Page 13: Couinaud’s Classification - Segment III
Segment III (Lateral Inferior Segment)
Description: Part of the left lobe.
Vascular Supply: Supplied by the descending branch of the left portal vein.
Page 14: Couinaud’s Classification - Segment IV
Segment IV (Medial Segment of the Left Lobe)
Description: Quadrate lobe.
Vascular Supply: Supplied by the horizontal segment of the left portal vein.
Page 15: Couinaud’s Classification - Segment V
Segment V (Anterior Segment of the Right Lobe)
Vascular Supply: Supplied by the anterior branch of the right portal vein.
Page 16: Couinaud’s Classification - Segment VI
Segment VI (Posterior Inferior Segment of the Right Lobe)
Vascular Supply: Supplied by the posterior branch of the right portal vein.
Page 17: Couinaud’s Classification - Segment VII
Segment VII (Posterior Superior Segment of the Right Lobe)
Vascular Supply: Supplied by the posterior branch of the right portal vein.
Page 18: Couinaud’s Classification - Segment VIII
Segment VIII (Anterior Superior Segment of the Right Lobe)
Vascular Supply: Supplied by the anterior branch of the right portal vein.
Page 19-26: Couinaud's Classification Summary
Segments I-VIII detailed,
Functional anatomy with supply and drainage clarified.
Page 27: Couinaud's Classification Summary - Segment Relations
Key Components
Review of segment identification through diagrams and features.
Page 28-29: Imaging Anatomy of the Liver
Sonographic Representations
Annotated CT images showcasing segments and vascular structures for identifying liver anatomy visually.
Page 30: Fissures of the Liver
Main Lobar Fissure
Functional division between right and left lobes.
Hyperechoic line extending from the right portal vein to the gallbladder fossa.
Page 31: Right Intersegmental Fissure
Features
Contains the right hepatic vein, landmark dividing anterior and posterior segments of the right lobe.
Page 32: Left Intersegmental Fissure
Features
Contains left hepatic vein, serving as the dividing line between medial and lateral segments of the left lobe.
Page 33: Ligamentum Venosum
Anatomy
Originates from the fetal ductus venosus, separates the caudate lobe from the left lobe.
Extends from the base of the left portal vein to the IVC.
Page 34: Ligaments of the Liver - Coronary Ligament
Description
Attaches the posterior liver to the diaphragm.
Forms the anterior and posterior boundaries of the bare area.
Continuous with the triangular ligaments and falciform ligament.
Page 35: Ligaments of the Liver - Falciform Ligament
Anatomy
Two-layered fold of peritoneum connecting liver to the anterior abdominal wall.
Extends from umbilicus to diaphragm, dividing at the superior portion into coronary and left triangular ligaments.
Contains ligamentum teres at its free margin.
Page 36: Ligaments of the Liver - Ligamentum Teres
Overview
Remnant of the fetal umbilical vein, suspended within the falciform ligament.
Joins the umbilical portion of the left portal vein.
Page 37: Ligaments of the Liver - Gastrohepatic Ligament
Description
Also called the lesser omentum.
Connects visceral liver surface to lesser curvature of the stomach and first part of the duodenum.
Page 38: Ligaments of the Liver - Hepatoduodenal Ligament
Function
Surrounds the portal triad (main portal vein, hepatic artery, common bile duct).
Forms the anterior boundary of the epiploic foramen.
Page 39: Ligaments of the Liver - Left Triangular Ligament
Description
Extends from the left lobe to the diaphragm, continuous with the falciform ligament on the left side.
Page 40: Ligaments of the Liver - Right Triangular Ligament
Overview
Extends from the right lobe to the diaphragm, forms the right lateral border of the bare area.
Page 41: Vascular Anatomy of the Liver - Portal Vein
Function
Provides 70-75% of the liver’s blood supply and contributes up to half of oxygen required by hepatocytes.
Formed by confluence of splenic vein and superior mesenteric vein (IMV drains into splenic vein).
Divisions:
Main Portal Vein
Right Portal Vein: Supplies caudate lobe and right lobe, divides into anterior and posterior branches.
Left Portal Vein: Supplies caudate lobe and left lobe, divides into medial and lateral branches.
Sonographic Appearance: Portal vein walls echogenic due to Glisson’s capsule.
Page 42: Vascular Anatomy of the Liver - Portal Vein Clarity
Illustrates the layout of the portal vein branches.
Page 43: Vascular Anatomy of the Liver - Hepatic Artery
Overview
Supplies 25-30% of liver’s blood supply, delivering oxygen-rich blood.
Originates from celiac trunk (axis): Divides into the common hepatic artery and gastroduodenal artery.
Sonographic Appearance: Low-resistance waveform with continuous antegrade flow.
Page 44: Vascular Anatomy of the Liver - Diagram of Arteries and Ducts
Highlights the anatomical relationships of hepatic artery and associated vessels.
Page 45: Vascular Anatomy of the Liver - Hepatic Veins
Function
Drain deoxygenated blood from the liver into the IVC.
Major Hepatic Veins:
Right Hepatic Vein: Divides anterior and posterior segments of the right lobe.
Middle Hepatic Vein: Divides right and left lobes.
Left Hepatic Vein: Divides medial and lateral segments of the left lobe.
Sonographic Appearance: Walls minimally echogenic and best visualized in transverse plane.
Page 46: Vascular Anatomy of the Liver
Visuals of Hepatic Relationships
Illustrates the practical aspects of hepatic venous drainage.
Page 47: Perihepatic Relationships
Surrounding Structures
Diaphragm: Adjacent to superior, posterior, and lateral liver aspects.
Right Kidney: Inferior to liver’s right lobe. Hepatorenal recess (Morison’s pouch) lies between anterior right kidney and liver's underside, important for free fluid detection.
Stomach: Located inferior and lateral to left lobe.
Duodenum: First and second portions lie anterior to porta hepatis.
Page 48: Normal Variants of the Liver - Riedel’s Lobe
Description
A tongue-like projection of the right lobe extending inferiorly, sometimes reaching iliac crest.
Associations: Incidental finding; more common in females.
Sonographic Findings: Inferior extension of right lobe below right kidney.
Page 49: Normal Variants of the Liver - Abnormal Left Lobe Position
Features
Left lobe may be on the right side mimicking other abnormalities.
Sonographic Findings: Left lobe posited to the right midline; left lobe extends significantly along left lateral abdominal wall. May be mistaken for fluid collections.
Page 50: Normal Variants of the Liver - Situs Inversus
Definition
A mirror-image arrangement of abdominal organs.
Sonographic Findings: Liver located on left side; right lobe positioned laterally and left lobe medially.
Page 51: Normal Variants of the Liver - Polysplenia/Asplenia Complex
Overview
May alter liver position and symmetry; sonographic findings include symmetrical lobes or midline liver location.
Page 52: Normal Variants of the Liver - Pseudofissures
Description
Indentations of the diaphragm causing apparent subdivisions in hepatic parenchyma without true separation.
Sonographic Findings: Normal variants in hepatic contour may prompt evaluation due to suspicion of a palpable mass.
Page 53: Functions of the Liver - Overview
Bile Formation
Produces ~800-1000 mL bile/day essential for fat digestion and absorption.
Hematologic Functions
Engages in blood production (hemopoiesis): only active during embryonic development.
Plasma Proteins: Synthesizes albumin, globulins, and antibodies.
Destruction of RBCs: Breaks down aged RBCs.
Page 54: Functions of the Liver - Metabolism
Major Metabolic Processes
Carbohydrate Metabolism:
Glycogenesis: Converts glucose to glycogen for storage.
Glycogenolysis: Breaks down glycogen back into glucose.
Gluconeogenesis: Produces glucose from non-carbohydrate sources.
Lipid Metabolism:
Desaturates fats & produces cholesterol/lipoproteins.
Protein Metabolism:
Synthesizes amino acids and converts excess to carbohydrates/fats.
Produces urea and uric acid as byproducts.
Page 55: Functions of the Liver - Storage
Reservoir Functions
Stores glycogen, glucagon, vitamins (A, D, B-complex), minerals (iron, copper), lipids, and amino acids.
Acts as a blood reservoir to help regulate circulatory dynamics.
Heat Production: Maintains body temperature through metabolic processes.
Detoxification
Processes medications, hormones, and bilirubin (converting from unconjugated to conjugated form for excretion).
Page 56: Laboratory Values for Liver Function Tests (LFTs)
Key Tests
AST (Aspartate Aminotransferase):
Elevated levels indicate conditions like hepatocellular disease and muscular injury.
ALT (Alanine Aminotransferase):
Highly specific for liver damage; elevated in hepatocellular disease.
ALP (Alkaline Phosphatase):
Specific indicator of biliary obstruction but increased levels can also indicate bone disease.
Page 57: Laboratory Values for Liver Function Tests (LFTs) - Bilirubin
Concepts
Elevated bilirubin leads to jaundice.
Types:
Direct (Conjugated): Increases with biliary obstruction or hepatocellular disease.
Indirect (Unconjugated): Increases with hemolysis or impaired liver uptake.
Page 58: Laboratory Values for Liver Function Tests (LFTs)
Summary of Tests
Albumin: Decreased levels are linked to chronic hepatocellular disease.
LDH (Lactic Dehydrogenase): Indicator across multiple tissues but LDH4 and LDH5 may suggest chronic liver damage.
PT (Prothrombin Time): Prolonged indicates impaired liver function.
AFP (Alpha-Fetoprotein): Elevated levels may indicate hepatomas or hepatoblastomas.
Page 59: Indications for Liver Examination
Symptoms and Signs
Clinical presentations suggesting liver pathology include:
Anorexia, fatigue, abdominal discomfort, fever.
Physical findings like jaundice and hepatomegaly.
Laboratory findings: elevated LFTs, including ALT, AST, bilirubin, ALP.
Page 60: Sonographic Technique for Liver Examination
Preparation
No specific preparation needed for liver studies, but fasting for gallbladder/pancreas evaluations is recommended.
Transducer Selection
Adults: 3–5 MHz transducer; Children/Small Adults: 5–7 MHz; Obese Patients: Lower frequency (around 2 MHz).
Page 61: Sonographic Technique for Liver Examination - Patient Positioning
Standard Protocol
Start in supine position; alternatives include left lateral decubitus, right oblique.
Adjust settings for optimal view (gain, focal zone).
Page 62: Sonographic Technique for Liver Examination - Optimization
Examination Protocol
Systematic evaluation of liver anatomy and vascular structures.
Use deep inspiration to enhance subcostal imaging.
Page 63: Normal Sonographic Appearance of the Liver
Overview
2D Appearance: Medium gray, homogeneous texture; smooth contour.
Page 64: Normal Sonographic Appearance of Liver Structures
Key Features
Hepatic Veins: Lumen anechoic with wall definition typically imperceptible.
Portal Veins: Prominent hyperechoic walls with hepatopetal flow.
Page 65: Normal Sonographic Appearance of the Liver - Doppler Findings
Flow Characteristics
Hepatic Artery: Low-resistance waveform with continuous flow.
Hepatic Veins: Display a characteristic “W” waveform influenced by cardiac activity.
Page 66: Liver Pathology Overview
Introduction
Overview of liver diseases affecting function and anatomy.
Page 67: Diffuse Liver Disease
General Aspects
Includes a variety of conditions that affect the liver diffusely.
Page 68: Diffuse Hepatocellular Disease
Characteristics
Affects hepatocytes, interfering with liver function.
Conditions include fatty liver, hepatitis, cirrhosis; seriousness depends on severity.
Page 69: Hepatic Steatosis (Fatty Liver)
Definition
Reversible condition characterized by fat accumulation in hepatocytes.
Also known as Non-alcoholic Fatty Liver Disease (NAFLD).
Risk Factors: Alcohol abuse, obesity, diabetes.
Page 70: Hepatic Steatosis - Clinical Presentation
Symptoms
Asymptomatic or mild hepatomegaly.
Slightly elevated LFTs.
/
Page 71: Hepatic Steatosis - Sonographic Appearance
Imaging Findings
Normal or enlarged liver with areas of increased echogenicity.
Posterior structures may be obscured based on fat deposition.
Page 72: Glycogen Storage Disease (GSD)
Definition
Genetic disorder of carbohydrate metabolism, resulting in excessive glycogen accumulation.
Types: GSD type I (Von Gierke’s) and GSD type II (Pompe disease).
Page 73: GSD - Clinical Presentation
Symptoms
Present in infancy with hepatomegaly, hypoglycemia, and delayed puberty.
Page 74: GSD - Sonographic Findings
Imaging Indicators
Liver increases echogenicity with potential liver cell adenomas. Also, nephromegaly noted.
Treatment for Type I: patients may survive into young adulthood with early therapy
Treatment for Type II: fatal within the first year of life due to respiratory failure
Page 75: Niemann-Pick Disease
Overview
A lipid storage disorder caused by inherited metabolic issues leading to lipid accumulation in various organs, including the brain, spleen, liver, lungs, and bone marrow.
Page 76: Niemann-Pick Disease - Clinical Presentation
Risk Factors:
inherited metabolic disorder with an autosomal recessive inhertiance pattern
a fatal condition, often leading to significant organ dysfunction and early mortality
Symptoms
Neurological symptoms, elevated LFTs, jaundice from bile composition impairment, cholestasis, feeding and swallowing difficulties.
Sonographic findings:
Hepatomegaly, increased parenchymal echogenicity, splenomegaly, enlarged lymph nodes.
Page 77: Reye's Syndrome
Definition
Rare, life-threatening disorder characterized by fatty infiltration of liver and encephalopathy, leading to acute liver failure and neurological symptoms.
Often follows viral infections.
Risk Factors
a rapidly progressive disorder, primarily affecting young children.
typically occurs after a viral infection, such as: cold, flu, and chickenpox.
can involve multiple organs, including kidneys and heart.
Associations
Linked to the use of aspirin or medications containing salicylates in children recovering from viral infections
Sonographic findings
fatty liver and hepatomegaly
Page 78: Reye's Syndrome - Clinical Presentation
Symptoms
Persistent vomiting, irritability, encephalopathy signs such as confusion.
Page 79: Hemochromatosis
Overview
Genetic disorder leading to excessive iron absorption, affecting liver predominantly.
liver is the primary organ deposition of excess iron.
can progress to cirrhosis if left untreated
Page 80: Wilson's Disease
Overview
Rare inherited disorder causing copper accumulation in multiple organs including the liver.
Sonographic features
echogenic liver
nodular lesions
presence of perihepatic fat layer
normal caudate lobe
eventually cirrhotic changes
Page 81: Hepatitis - Overview
Definition
Inflammation of the liver due to various causes including viral infections, alcohol, nonalchoholic steatohepatitis (NASH) and medications.
Page 82: Types of Hepatitis
Key Forms
Hepatitis A: fecal-oral route, often through contaminated food or water; typically self-limiting.
Hepatitis B: blood/body fluid transmission leading to chronic forms, like chronic hepatitis, cirrhosis, or hepatocellular carcinoma.
Hepatitis C: blood-to-blood contact, often via shared needles or transfusions before 1992, high risk of chronicity like chronic hepatitis, cirrhosis, and liver cancer.
Page 83: Alcohol-Induced Hepatitis
Overview
Chronic use of alcohol resulting in inflammation, steatosis, fibrosis.
Medication-induced hepatitis
caused by toxicity from certain drugs, such as acetaminophen or chemotherapeutic agents.
Nonalcoholic steatohepatitis (NASH)
associated with metabolic syndrome, obesity, and diabetes.
Page 84: Clinical Presentation of Hepatitis
Symptoms
Variable depending on stage and causes; includes fatigue, jaundice, abdominal pain, dark urine and pale stools, nausea and vomiting, and loss of appetite.
Laboratory findings
elevated AST and ALT, with a marked increase in acute viral hepatitis.
elevated bilirubin, particularly in cases involving jaundice.
increased alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) in cholestatic hepatitis.
Page 85: Acute Hepatitis - Imaging Appearance
Key Features
Echogenicity normal or reduced with sample portal vein prominence causing a “starry night” appearance, and possibly gallbladder wall thickening.
Hepatomegaly
Chronic Hepatitis - sonographic appearance
increased echogenicity of liver parenchyma due to fatty changes and fibrosis
coarse texture
decreased definition of portal vein walls
may show signs of portal hypertension, such as splenomegaly, ascites, or varices.
Complications of Hepatitis
progression to cirrhosis, characterized by irreversible liver damage
increased risk of developing hepatocellular carcinoma (HCC)
portal hypertension with associated varices or splenic involvement
liver failure in severe cases.
Page 86: Cirrhosis
Definition
Progressive liver disease characterized by fibrosis, parenchymal scarring, and nodular regeneration of hepatocytes and liver changes, causing dysfunction.
Page 87: Cirrhosis - Pathophysiology
Overview
Inflammatory processes lead to fibrous formation and portal hypertension.
nodular regeneration: damaged hepatocytes attempt to regenerate, resulting in disorganized nodules surrounded by fibrous hands.
Page 88: Cirrhosis - Causes and Risk Factors
Key Factors
Alcohol abuse (most common cause in the U.S.), viral hepatitis, metabolic issues, and autoimmune conditions.
chronic hepatitis B and hepatitis C are major global causes of cirrhosis.
Hepatitis C is the most frequent cause of liver transplantation in the U.S.
Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH)
autoimmune hepatitis, primary biliary cholangitis (PBC)
primary sclerosing cholangitis (PSC)
inherited or genetic disorders
biliary obstruction
chronic heart failure
Page 89: Clinical Presentation of Cirrhosis
Symptoms
Early (compensated) signs may include fatigue, weakness, anorexia and unintended weight loss, and may be asymptomatic; late signs (decompensated) show jaundice, ascites, hepatic encephalopathy, GI bleeding, edema, spider angiomas, palmar erythema, and potential liver failure changes.
Page 90: Cirrhosis - Laboratory Findings
Observations
Altered LFTs, indicative prothrombin time changes, possible portal hypertension effects.
elevated AST, ALT, and bilirubin levels
decreased albumin and serum proteins
ammonia levels elevated in cases of hepatic encephalopathy
Sonographic Appearance of Cirrhosis
early stage: hepatomegaly. diffuse fatty infiltration with increased echogenicity, scalloped liver surface
advanced stage: small, shrunken right and left lobes with a relatively enlarged caudate lobe
coarse, hyperechoic parenchymal texture, nodular liver surface, associated findings include: dilated portal vein with potential heptofugal flow, and splenomegaly, ascites.
Page 91: Doppler Findings - Cirrhosis
Flow Characteristics
Varied patterns may indicate advanced conditions, portals decrease, and hepatofugal flow may develop.
more prominent in advanced stages
Portal vein: decreased flow velocity, hepatofugal flow, or thrombosis
Hepatic veins: altered waveforms due to fibrosis and altered cardiac influences
Hepatic artery: increased resistive index due to portal hypertension
Page 92: Summary on Cirrhosis Management
Complications
Includes risk of hepatocellular carcinoma (HCC), portal hypertension effects, hepatorenal syndrome (HRS), hepatic encephalopathy and liver failure.
Page 93: Vascular Abnormalities
Overview
Conditions related to hepatic and portal vascular issues, including flow dynamics, vessel anatomy, or pathology affecting blood supply and drainage.
Common vascular abnormalities
portal hypertension, portal vein thrombosis, budd-chiari syndrome, hepatic artery aneurysm, and arteriovenous malformation (AVM) and fistulas
Page 94: Portal Hypertension
Definition
Increased pressure in the portal venous system, typically above 10 mmHg, affecting flow and presenting complications.
Causes for portal hypertension
Prehepatic: problem occurs before the liver, portal vein thrombosis, splenic vein thrombosis
Intrahepatic: problem occurs within the liver ex.) cirrhosis and fibrosis
Posthepatic: problem occurs after the liver, ex.) budd-chiari syndrome and cardiac congestion
Page 95: Sonographic Appearance - Portal Hypertension
Key Features
Dilated portal vein (>13mm in diameter), splenomegaly, ascites, hepatofugal (reversed) flow in the portal vein.
Complications for Portal Hypertension
esophageal or gastric varices leading to life threatening bleeding
splenomegaly with hypersplenism
Page 96: Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Overview
Minimally invasive procedure where a doctor creates a connection between the portal vein and hepatic vein inside the liver using a stent. TIPS allows blood to bypass liver pressure, reducing pressure in the portal system, often used in advanced cases.
Page 97: Transjugular Intrahepatic Portosystemic Shunt (TIPS) Findings
Sonographic Doppler Results
Normal velocities and flow characteristics assist in evaluating complications.
Normal TIPS velocity: 90-190 cm/s
Normal portal vein velocity before entering the TIPS: -30 cm/s
phasic waveform
Stenosis TIPS sonographic doppler findings
velocity of >190 cm/s at a stenotic segment
velocity of <90 cm/s in non-stenotic segments
Page 98: Portal Vein Thrombosis
Definition
Clot formation within the portal vein, leading to potential liver impairments.
Causes of Portal Vein Thrombosis
cirrhosis
malignancy (HCC)
hypercoagulable conditions
Sonographic Appearance of Portal Vein Thrombosis
echogenic material within the portal vein
absence of color doppler flow in the affected vein
collateral vessel formation
Page 99: Budd-Chiari Syndrome
Definition
Obstruction of hepatic venous outflow due to thrombosis or compression of the hepatic veins or IVC leading to liver dysfunction and symptoms.
Causes of Budd-Chiari Sydnrome
hypercoagulable states (polycythemia vera, oral contraceptives, pregnancy)
tumor invasion (HCC)
idiopathic cases
Clinical Presentation for Budd-Chiari Syndrome
abdominal pain
hepatomegaly
ascites
Sonographic Appearance for Budd-Chiari Syndrome
absent or diminished flow in hepatic veins
narrowing or occlusion of hepatic veins or IVC
hepatomegaly with caudate lobe enlargement
ascites
Complications of Budd-Chiari Syndrome
portal hypertension
liver failure
Page 100: Hepatic Artery Aneurysm
Definition
Rare focal hepatic artery dilation, with potential risks for rupture.
Causes of Hepatic Artery Aneurysm
Atherosclerosis
trauma or infection
connective tissue disorders
Sonographic Appearance of Hepatic Artery Aneurysm
anechoic or hypoechoic mass near the hepatic artery
color doppler flow showing swirling (yin-yang sign)
Complications of Hepatic Artery Aneurysm
rupture leading to hemorrhage
Page 101: Arteriovenous Malformation & Fistula
Description
Abnormal connections between arteries and veins, bypassing capillary beds, potentially leading to various conditions.
AVMs are usually developmental abnormalities
AVFs are usually acquired lesions
Causes of AVM & AVF
Congenital
trauma or iatrogenic injury
cirrhosis
Sonographic Appearance of AVM & AVF
Turbulent flow with high velocity arterial and venous signals on doppler
enlarged feeding arteries and draining veins
Page 102: Hematoma
Definition
Blood collection within or around the liver due to trauma or vascular injury.
Causes of Hematoma
Trauma: the most common cause of hepatic hematomas
rupture of neoplasms, such as: adenoma, metastatic choriocarcinoma, cavernous hemangioma
Categories of Liver Trauma
Transcapsular laceration and rupture: blood exits the liver and extends into the peritoneal cavity
Subcapsular hematoma: blood accumulates between the liver capsule and parenchyma, creating a confined collection
Intraparenchymal hematoma: blood collects within the liver disease
Page 103: Hematoma Findings
Incidence
In children, blunt abdominal trauma accounts for over 90% of all abdominal injuries
Clinical Presentation for a Hematoma
Pain, especially in the upper right abdomen
hypotension, indicative of significant blood loss
Laboratory Values for a Hematoma
A large hematoma may lead to a decrease in hematocrit, signaling significant blood loss
Sonographic Appearance for a Hematoma
Varies by trauma type; typically identified via dimensions and patterns.
Most trauma affects the right lobe, particularly the posterior segment
Acute hematoma: appears anechoic
Subacute hematoma: increasing echogenicity and complexity due to fibrin organization
Organized hematoma: appears solid and isoechoic to liver parenchyma.
Specific patterns: intraparenchymal hematoma: poorly defined margins
Specific patterns: subcapsular hematoma: fluid collection between the liver capsule and parenchyma, often displacing liver tissue toward the porta hepatis
Page 104: Benign Masses
Overview
Includes cysts, abscesses, and lesions—often identifiable through imaging.
Page 105: Liver Cysts
Defintion
Fluid-filled mass with an epithelial lining that may or may not cause symptoms depending on origin.
true liver cysts are congenital
cystic masses caused by trauma, parasitic infections, or inflammatory changes do not have an epithelial lining and are not considered true cysts.
Incidence of Liver Cysts
The right lobe of the liver is affected twice as often as the left lobe.
Adult Polycystic Disease: app. 1 in 1,000 individuals, more common in females than males, typically presents in the 5th to 7th decade of life.
Clinical Presentation of Liver Cysts
usually asymptomatic
large or multiple cysts may cause: liver enlargement, biliary obstruction, and epigastric pain.
Sonographic Appearance of Liver Cysts
Simple cysts: anechoic, thin walled, ovoid, well defined mass with posterior acoustic enhancement.
Complex cysts: internal echoes may suggest hemorrhage or infection.
Page 106: Pyogenic (Bacterial) Abscess
Definition
Infected fluid collection due to bacteria, typically requiring intervention.
A localized collection of pus and debris resulting from a bacterial infection.
Bacteria enter the liver most commonly via the biliary tree.
The most common causative organism is Escherichia coli (E. coli)
Risk Factors of Pyogenic (Bacterial) Abscess
Biliary tract obstruction
Infection
Hepatic tumors
Pre-existing hepatic cysts
Clinical Signs and Symptoms for Pyogenic (Bacterial) Abscess
fever (febrile presentation)
pain in the abdomen or right upper quadrant
pleuritic pain (sharp pain worsening with breathing)
nausea
vomiting
diarrhea
Laboratory Findings for Pyogenic (Bacterial) Abscess
elevated white blood cell (WBC) count
elevated liver function tests (LFTs)
Anemia
Sonographic Appearance for Pyogenic (bacterial) Abscess
Size varies, ranging from 1cm to very large
most commonly found in the right lobe of the liver (80% of cases)
round or ovoid in shape
Page 107: Amebic (Parasitic) Abscess
Overview
Liver infection from Entamoeba histolytica leading to inflammation and symptoms.
though primarily a colon infection, amebic dysentery can spread to the liver, lungs, and brain
deposit in portal vein capillaries
Clinical Signs and Symptoms of Amebic (Parasitic) Abscess
fever
abdominal pain
diarrhea
Melena (dark, tarry stools due to GI bleeding)
Complications of Amebic (Parasitic) Abscess
rupture into pleuropulmonary structures
rupture into the peritoneal cavity
Laboratory Findings for Amebic (Parasitic) Abscess
elevated WBC count
elevated LFTs
Sonographic Appearance for Amebic (Parasitic) Abscess
well-defined thin-walled lesion
round or oval in shape
hypoechoic compared to normal liver parenchyma
Page 108: Fungal Infection
Definition
Rare infections in immunocompromised patients often requiring treatment.
Fungal liver infections
most commonly caused by candidiasis (yeast)
occur in patients who have: HIV/AIDS, organ transplants, undergoing chemotherapy
Sonographic Appearance for Fungal Infection
hepatomegaly is often present
early disease: “wheel within a wheel” lesions, a pattern with a hypoechoic rim surrounding a central echogenic focus
progression: lesions evolve to a bulls eye appearnce with a hyperechoic center
late disease: lesions become uniformly hypoechoic
lesions are typically multiple
Page 109: Schistosomiasis
Definition
Parasitic infection caused by waterborne Schistosoma worms, commonly found in areas with contaminated water supplies, leading to abdominal symptoms and potential liver complications.
infection occurs when cercariae (immature worms) penetrate the skin and migrate through the lymphatic and venous systems
Clinical Presentation for Schistosomiasis
RUQ pain
Fever
Leukocytosis
Signs and symptoms associated with portal hypertension: ascites, varices, splenomegaly
Sonographic Appearance for Schistosomiasis
liver size is normal or small
thickened and highly echogenic walls of intrahepatic portal vein radicles, due to fibrosis
portal vein dilation
Page 110: Echinococcal Cyst (Hydatid Cyst)
Definition
Parasitic infestation from dog feces leading to cyst formation in the liver.
caused by the parasite Echinococcus granulosus, the primary agent of hydatid disease in humans
common in regions where wild game and sheep are significant food sources, particularly in developing countries
transmission: eggs of the parasite are excreted in the feces of infected dogs
usually 3 animals involved
Incidence of Echinococcal Cyst (Hydatid Cyst)
approximately 50% of cysts are located in the liver
Clinical Presentation for Echinococcal Cyst (Hydatid Cyst)
Jaundice may occur if the cysts obstruct the biliary ducts
elevated ALP levels
Sonographic Findings for Echinococcal Cyst (hydatid Cyst)
simple cysts with thick or calcified walls
large cyst (mother cyst) containing smaller daughter cysts within it
“water lily sign”
Page 111: Cavernous Hemangioma
Definiton
Common benign liver lesion, typically asymptomatic unless large.
A benign tumor consisting of a large network of vascular spaces lined with endothelium and filled with red blood cells
these lesions may slowly enlarge over time and exhibit signs of degeneration, fibrosis, or calcification
Incidence for Cavernous Hemangioma
most common benign liver lesion
most frequently located in the right lobe of the liver
more prevalent in females
Clinical Presentation for Cavernous Hemangioma
typically asymptomatic
most lesions are subcapsular or located periphererally
generally less than 3 cm in size and not clinically palpable.
Sonographic Appearance for Cavernous Hemangioma
round
hyperechoic
homogenous solid masses
with sharply defined margins
Page 112: Focal Nodular Hyperplasia (FNH)
Description
Benign hepatic mass often identified during ultrasound without high risk of complications.
benign liver mass composed of: abnormally arranged hepatocytes, kupffer cells, bile duct elements, fibrous connective tissue
Incidence and Clinical Symptoms
2nd most common benign liver mass after cavernous hemangioma
occurs more frequently in reproductive age females (20-40)
Sonographic Appearance for FNH
often isoechoic
may occasionally appear hypoechoic or hyperechoic
a central stellate scar: most often appears hypoechoic, though it may occasionally appear hyperechoic
Page 113: Adenoma
Overview
Benign liver lesion often associated with hormonal influences and potential risks of rupture.
Page 114: Mesenchymal Hamartoma
Definition
Congenital benign liver tumor primarily found in children.
Page 115: Malignant Tumors
Overview
Includes hepatoblastoma and HCC—identified through imaging and clinical findings.
Page 116: Hepatoblastoma
Clinical Characteristics
Most common primary liver neoplasm in children.
Page 117: Hepatocellular Carcinoma (HCC)
Overview
Most frequent liver cancer associated with liver issues and risk factors.
Hepatic Angiosarcoma (Hemangiosarcoma)
Definition
a rare and aggressive malignant neoplasm originating from endothelial and fibroblastic tissue
Incidence for Hepatic Angiosarcoma (Hemangiosarcoma)
extremely rare, accounting for less than 2% of primary liver cancers
Page 118: Metastatic Disease
Definition
Tumor spread to the liver, often indicating systemic spread and requiring management.