Liver Anatomy and Ultrasound – Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering liver anatomy, ligaments, vessels, Couinaud segments, sonographic findings, and common pathologies as presented in the notes.

Liver

The organ occupying the right upper quadrant (RUQ) and part of the epigastrium; lies inferior to the diaphragm and is largely covered by peritoneum except for the Bare Area resting on the diaphragm.

Right lobe

The larger right hepatic lobe with anterior and posterior segments; separated from the left lobe by the main lobar fissure.

Left lobe

The left hepatic lobe with medial and lateral regions; contains the falciform ligament and the ligamentum teres within it.

Caudate lobe

A small posterior lobe located between the ligamentum venosum and the IVC; often spared from disease due to unique venous drainage.

Quadrate lobe

Part of the left lobe, inferior to the porta hepatis (often referred to as part of the left medial segment).

Bare area

Triangular area of the liver not covered by peritoneum; rests directly on the diaphragm.

Glisson's capsule

Peritoneal covering of the liver; surrounds the liver except for the Bare Area.

Falciform ligament

Ligament connecting the liver to the anterior abdominal wall and containing the ligamentum teres within it.

Ligamentum teres

Round ligament; remnant of the fetal umbilical vein that runs in the falciform ligament and may recanalize with portal hypertension.

Ligamentum venosum

Remnant of the ductus venosus; separates caudate from left lobe; intrahepatic portion lies within the liver.

Ductus venosus

Fetal shunt that bypasses the liver; its remnant forms the ligamentum venosum after birth.

Coronary ligament

Ligament anchoring the liver to the diaphragm along the diaphragmatic surface.

Right triangular ligament

Peritoneal reflection anchoring the right lobe to the diaphragm.

Left triangular ligament

Peritoneal reflection anchoring the left lobe to the diaphragm.

Main lobar fissure

Fissure that separates the right and left lobes; a landmark between the gallbladder neck and the portal vein junction.

Right intersegmental fissure

Divides the right lobe into anterior and posterior segments; landmark is the right hepatic vein.

Left intersegmental fissure

Divides the left lobe into medial and lateral segments; landmarks are the left hepatic vein and left portal vein.

Bare area (repeat)

See above: area not covered by peritoneum; rests on the diaphragm.

Portal triad

Hepatic artery, portal vein, and common bile duct encased in a collagenous sheath within the hepatoduodenal ligament.

Portal vein

Formed by the SMV and splenic vein; carries blood from the bowel to the liver; hepatopetal flow; typically 13 mm diameter; divides into left and right portal veins with further branches.

Hepatic artery

Oxygenated arterial supply to the liver; proper hepatic artery arises from the celiac trunk; variations include replaced hepatic arteries.

Common bile duct

Duct that drains bile from the liver and gallbladder into the duodenum; seen within the portal triad on ultrasound.

Hepatic veins

Veins (RHV, MHV, LHV) that drain the liver into the IVC; walls are relatively non-echogenic.

Right hepatic vein

Vein that divides the right lobe’s anterior and posterior segments; drains into the IVC.

Middle hepatic vein

Vein that drains the central/lateral aspects of the liver; drains into the IVC.

Left hepatic vein

Vein that divides the left lobe’s medial and lateral segments; drains into the IVC.

Inferior vena cava (IVC)

Large vein into which hepatic veins drain; returns filtered blood to the heart.

Hepatopetal

Blood flow toward the liver, as seen in normal portal venous circulation.

Portal venous supply percentage

About 70-80% of liver blood supply comes from the portal venous system.

Hepatic arterial supply percentage

About 20-30% of liver blood supply comes from the hepatic artery.

Couinaud segments

8 functional segments of the liver defined by vasculature and bile ducts, useful for surgical planning.

Segment I (Caudate)

Caudate lobe segment (I) in Couinaud’s scheme.

Segment II

Left lateral superior segment in Couinaud’s scheme.

Segment III

Left lateral inferior segment in Couinaud’s scheme.

Segment IVa

Left medial superior segment in Couinaud’s scheme.

Segment IVb

Left medial inferior (quadrate) segment in Couinaud’s scheme.

Segment V

Right anterior inferior segment in Couinaud’s scheme.

Segment VI

Right posterior inferior segment in Couinaud’s scheme.

Segment VII

Right posterior superior segment in Couinaud’s scheme.

Segment VIII

Right anterior superior segment in Couinaud’s scheme.

Intersegmental vessels

Hepatic veins that run between segments and lobes (intersegmental).

Intrasegmental vessels

Portal veins that run through the center of each segment (intrasegmental).

Gallbladder fossa

Anatomical area on the liver where the gallbladder sits; used as a landmark for segments and fissures.

porta hepatis

The gateway to the liver where the portal triad enters: portal vein, hepatic artery, and bile duct.

Liver vessels echogenicity

Portal veins have thicker, more echogenic walls than hepatic veins on ultrasound.

Liver assessment landmarks in ultrasound

Main lobar fissure, right/left intersegmental fissures, gallbladder, portal vein, hepatic artery, CBD.

Hepatic duct

Duct carrying bile from the liver; seen near the porta hepatis alongside the hepatic artery and portal vein.

Morrison’s pouch

Right subhepatic space (hepatorenal recess); evaluated for fluid in liver ultrasound exams.

Liver function

Metabolic roles including detoxification, nutrient processing, bile production, protein synthesis, and bilirubin handling.

Agenesis of liver

Rare developmental anomaly where one or more lobes are absent; incompatible with life if full agenesis occurs; compensatory hypertrophy of remaining lobes may occur.

Situs inversus

Anatomic reversal of organs (including liver on the left and spleen on the right) relative to normal position.

Accessory fissures

Additional fissures in the liver caused by infolding of peritoneum; inferior accessory fissure is a true example.

Vascular anomalies of liver

Variations in hepatic arteries (e.g., replaced arteries from nonstandard origins) and portal/hepatic venous anatomy.

Replaced left hepatic artery

Left hepatic artery arising from the left gastric artery rather than the proper hepatic artery.

Replaced right hepatic artery

Right hepatic artery arising from the superior mesenteric artery (SMA) rather than the proper hepatic artery.

Portal vein anomalies

Atresias, strictures, or obstructing valves in portal venous anatomy.

Accessory hepatic veins

Additional hepatic veins that may drain into the middle hepatic vein or right hepatic vein, more variable anatomy.

Liver function tests (LFTs)

Laboratory tests including AST, ALT, ALP, bilirubin, PT, albumin/globulins used to assess liver function.

AST

Aspartate aminotransferase; elevated in acute hepatitis and cirrhosis.

ALT

Alanine aminotransferase; more specific for liver injury than AST.

Alkaline phosphatase (ALP)

Elevated in intra/extrahepatic obstruction and carcinoma.

Bilirubin

Bilirubin (indirect/direct/total) reflects bilirubin metabolism; elevated in hemolysis, obstruction, or liver dysfunction.

Prothrombin time (PT)

Clotting time affected by liver synthetic function; part of liver function assessment.

Albumin and globulins

Serum proteins produced by the liver; levels reflect liver synthetic function.

Agenesis vs situs inversus

Agenesis is absence of a lobe; situs inversus is overall organ reversal, including liver position.

Liver Doppler vessels

Vessels interrogated include the portal vein, hepatic artery, and hepatic veins to assess flow and pressures.

Liver protocol basics

Basic sonographic liver protocol includes evaluating size, echotexture, vascular structures, fissures, ligaments, and segments.

NPO for liver ultrasound

Nothing by mouth for 6-8 hours prior to exam to reduce bowel gas and improve image quality.

Transducer frequency for liver ultrasound

2.5-4 MHz curvilinear or 3-5 MHz curvilinear transducers are commonly used.

Patient positions for liver ultrasound

Supine, oblique, and decubitus positions as needed to visualize different liver aspects.

Normal liver size

Longitudinal liver length approximately 15 cm in a healthy adult.

Hepatic vasculature landmarks

Key landmarks include RHV, MHV, LHV, portal vein bifurcation, and porta hepatis.