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.