Liver Flashcards
Facts
- Intraperitoneal (except for bare area)
- Covering = Glisson Capsule
- 3 main lobes = right, left, caudate
- Processing plant = metabolizes the good stuff, gets rid of the bad, makes bile
- Portal triads = portal vein, hepatic artery, bile duct (go to hepatocyte)
Anatomy
- Intersegmental/hepatic = between segments
Separates segments: Fissures, hepatic veins, ligaments, GB - Intrasegmental/hepatic = inside segments/liver
Do NOT separate: Portal veins, bile ducts, hepatic artery
Caudate lobe
separated from left lobe by ligamentum venosum and bordered posteriorly by IVC
Ligaments
- Echogenic band on sono. Ligaments always there.
- Ligamentum = ligaments formed by closure of blood vessels.
- Ligamentum venosum: in utero = ductus venosus
- Ligamentum teres AKA round ligament: in utero = umbilical vein. Inside falciform ligament
Vasculature
- Supply: Portal vein and hepatic artery. 70% of blood supplied by MPV.
MPV and proper hepatic artery enter at porta hepatis.
Both are HEPATOPETAL / towards liver.
PV steady, minimally phasic. HA low resistance
Both are intrasegmental. Branches match segments.
- Drainage: Hepatic veins. Drain into Rt atrium
HEPATOFUGAL /away from the liver and pulsatile
HV are intersegmental. Between and split segments
Variants
- Reidel’s lobe: extension of rt lobe over rt kidney. May cause “false-positive”. To distinguish from hepatomegaly, look at left lobe for enlargement
- Papillary process: inferior extension of the caudate lobe
Sonography
Normal up to 15cm along mid-hepatic line (dome to inf tip)
Slightly echogenic compared to kidney
MPV diameter ≤ 13mm
DIFFUSE
- Liver disease and labs
- Diffuse disease = think function! Liver enzymes»_space; ALT, ALP, AST
- ALT = Alanine transaminase
- ALP = Alkaline phosphatase
- AST = Aspartate transaminase
Conjugated VS Unconjugated
- Indirect (Unconjugated) = Not yet gone through the liver. RBC hemolysis
- Direct (Conjugated) = Acute liver disease / Hepatitis / Biliary obstruction
- Total = Usually liver disease/failure
Fatty liver infiltration AKA hepatic steatosis
- Most common diffuse liver disease.
- Most likely reason for elevated LFTs.
- Hepatocytes (liver cells) fill with fatty deposits.
focal fatty infiltration and focal fatty sparing
- Focal fatty infiltration: Focal echogenic area. Patch of fatty liver. (No mass effect)
- Focal fatty sparing: Focal hypoechoic area. Patch of normal liver. Most common location: next to GB/porta hepatis (No mass effect)
Cirrhosis
- Liver cell death and fibrosis/liver failure.
- Most common cause is alcoholism
- Clinical: Poor liver function symptoms = elevated LFTs, jaundice (elev total or direct bilirubin), fatigue, weight loss, diarrhea
- Sono: heterogeneous/coarse texture, small right lobe, enlarged caudate lobe, nodular surface, ascites
Micronodular vs Macronodular Cirrhosis
- Micronodular: smaller nodules when caused by alcoholism
- Macronodular: >1cm nodules when caused by hepatitis
Portal Hypertension
- Most common cause is cirrhosis.
- Increased pressure on portal system, redirecting blood flow AWAY from liver. Blood flow can only flow into lower pressure. When pressure of liver disease increases too much, resists flow coming into it. Flow drawn to other lower pressure channels.
- The elevation of blood pressure within the portal venous system
Treatment: TIPSS transjugular intrahepatic portosystemic shunt
Communication or bridge between PV and HV to decompress the portal vein and normalize flow direction.
Portal vein compression / thrombosis
Obstruction of PV is most commonly caused by tumors or lymphadenopathy. Thrombosis may be caused by increased liver resistance or increased clotting factors
Budd-Chiari Syndrome
- Occlusion of hepatic veins and possibly IVC. Leads to liver congestion and eventual liver necrosis, caudate lobe enlarges to compensate (Caudate drains directly into IVC)
- Sono: Hepatomegaly, enlarged caudate lobe, absent flow hepatic veins
Infection = acute hepatitis or abscess
- Differences between acute hepatitis and abscess. Hepatitis is a DIFFUSE infection so LFT’s will always be abnormal. Abscess is FOCAL = LFTs may be normal
- Diffuse labs + fever = Whole organ infection “acute -itis”
- Fever + focal finding = Abscess
Hepatitis
- Most common Hep A and B.
- Hep C is most likely cause of needing liver transplantation
-itis= inflammation or infection. - Initially will be acute, may become chronic if damages the liver.
- Acute -itis means active infection. Solid organ acute -itis usually are clinical diagnosis.
Acute hepatitis
Most common acute: Hepatitis A (fecal-oral route)
Chronic hepatitis
Most common chronic: Hepatitis C (bodily fluids)
Abscesses Clinical
infection symptoms, fever, pain, leukocytosis
Hydatid
- Echinococcal Parasite
- Water-lily sign / Daughter cysts / Membranes
Amebic
- Parasite from water
- GI first = diarrhea
Pyogenic
Pyo = Pus / Bacteria
From other infection = HX of -itis / Surgery / Bx
Candida/Fungal
Candida albicans
Immunocompromised pt Cancer, transplant, HIV
Target or halo multiples
FOCAL masses
- Benign/non-endocrine = asymptomatic
- Malignant = symptomatic
Cysts
- Benign and mostly asymptomatic. Associated with PKD (polycystic kidney disease). May have pain if hemorrhagic.
- Sono: anechoic, complex with posterior enhancement
Cavernous hemangioma
Most common benign liver tumor. Echogenic solid mass
Hepatocellular Adenoma
Associated with oral contraceptives. Varied, may be echogenic
Lipoma
Made of fat. Hyperechoic
Focal Nodular Hyperplasia
- 2nd most common benign liver tumor.
- “Stealth lesion” because it may be isoechoic to liver tissue. Central scar with vascularity. Look for “mass effect”
Hematoma
- “Bleed” from trauma or surgery.
- Intraparenchymal hematoma: within the organ/liver. More focal appearing
- Subcapsular: around the liver, just under the Glisson capsule. Like “free fluid”
- Clinical: Trauma or Biopsy Hx, decreased hematocrit, pain
- Sono: Anechoic to echogenic depending on age
Cancer
Weight loss, fatigue, abnormal labs and jaundice if obstructive but not always Hepatomegaly
Hepatocellular Carcinoma - HCC aka hepatoma
- Most common primary liver cancer.
- Increased risk = chronic liver disease, cirrhosis, hepatitis. Tumor marker = elevated AFP (alphafetoprotein)
- Sono: usually solitary, hypoechoic mass, ascites
Metastasis
- Most common cancer found in liver.
- Multiple masses. Lung, colon, breast most common sources. The liver is the most common location for mets
Hepatoblastoma
Pediatrics version of HCC. Elevated AFP, same clinical, similar sono appearance. Increased risk in Beckwith-Wiedemann syndrome (growth disorder)
Liver Transplants
Hepatitis C most common reason requiring liver transplant
