EXAM 2 Liver Duplex

List the 4 key facts about the left lobe of the liver.

• It has what 2 Lobes.

• It is divided into segments by the what vein

• It contains the what vein and artery?

• It is imaged using the which window.

• It has medial and lateral lobes.

• It is divided into segments by the left hepatic vein.

• It contains the left portal vein and left hepatic artery.

• It is imaged using the subxiphoid window.

List the 2 key facts about the caudate lobe.

• It is located near the what.

• It is a separate ____with a separate ____supply

• It is located near the IVC.

• It is a separate lobe with a separate blood supply

List the 5 key facts about the right lobe of the liver.

• It has what 2 lobes.

• It is separated from the what lobe by the what list 2

• Divided into segments by what vein

• contains what vein and what artery

• what two windows can you use?

• It has anterior and posterior lobes.

• It is separated from the left lobe by the IVC and gallbladder.

• It is divided into segments by the right hepatic vein.

• It contains the right portal vein and right hepatic artery.

• It is imaged using subcostal or intercostal windows.

What is the normal longitudinal dimension of the liver?

The normal longitudinal dimension is 15–17 cm.

Explain the main function of the portal system.

The portal system drains - what? from the ___and ___into the liver.

The portal system drains nutrient-rich blood from the bowel and spleen into the liver.

List the 2 main blood supplies to the liver and their percentages.- under normal conditions:

which one is the main source of supply for the liver?

• Portal vein: 70% - main source of supply for the liver

• Hepatic artery: 30%

What is normal portal venous flow direction called?

Normal portal venous flow is hepatopedal, meaning flow is toward/into the liver.

What happens to the portal vein branches as they terminate in the liver?

They get smaller.

Is the portal system part of the regular venous system?

No. It is separate from the venous system.

List the 4 vessels of the portal venous system.

• Main portal vein, or MPV

• Superior mesenteric vein, or SMV

• Splenic vein

• Inferior mesenteric vein, or IMV

How is the main portal vein formed?

The MPV is formed _______to the ___—_by the union of the what vein and what vein.

The MPV is formed posterior to the pancreas by the union of the superior mesenteric vein and splenic vein.

What is the length of the main portal vein trunk?

The main trunk is 5–7 cm long.

Describe the course of the main portal vein.

Courses _____to _____, between layers of lesser omentum to where

It courses posterior to the duodenum, then between the layers of the lesser omentum to the porta hepatis.

What is the sonographic appearance of portal vein walls?

Portal vein walls are echogenic.

List the 2 main branches of the portal vein.

• Right portal vein

• Left portal vein

List the 2 branches of the right portal vein.

• Anterior

• Posterior

List the 2 branches of the left portal vein.

• Medial

• Lateral

What direction does the common hepatic artery travel?

It travels rightward or leftward to the liver?

It travels rightward to the liver.

List the 2 Doppler waveform features of the common hepatic artery.

• Low resistance

• Spectral broadening

List the 3 arterial branches of the common hepatic artery.

• Gastroduodenal artery

• Proper hepatic artery

• Right gastric artery

Where is the proper hepatic artery imaged?

It is imaged through the _____window at the where?

It is imaged through the intercostal window at the porta hepatis.

Where are the right and left hepatic arteries located?

They are within the liver parenchyma.

Which ______artery supplies the right lobe?

The right hepatic artery supplies the right lobe.

Which ____-artery supplies the left lobe?

The left hepatic artery supplies the left lobe.

What Doppler waveform should the hepatic artery have?

It should have a low-resistance waveform.

List the 3 key facts about the intrahepatic ducts.

• They are within the where?

• They include what ducts.

• They join with the ____duct. to form the what?

• They are within the liver parenchyma.

• They include right and left ducts.

• Joins with cystic duct to form common bile duct

List the 2 key facts about the common bile duct.

• It extends from the what to the what.

• what is the normal size of the common bile duct

• It extends from the porta hepatis to the pancreatic head.

• Normal size is 4–6 mm.

Where do hepatic veins originate and drain? and at the level of the what?

They originate in the liver and drain into the IVC at the level of the diaphragm

What happens to hepatic veins as they approach the diaphragm?

They enlarge as they near the diaphragm.

List the 3 hepatic vein tributaries.

• Right hepatic vein

• Middle hepatic vein

• Left hepatic vein

What is the wall appearance of hepatic veins?

Hepatic veins have non-echogenic walls.

What do hepatic veins do anatomically? - They divide the liver into ______?

They divide the liver into segments.

List the 3 hepatic veins and what each one divides. (which one is the largest?)

• RHV: largest hepatic vein; divides the right lobe into anterior and posterior segments.

• MHV: divides the liver into right and left lobes.

• LHV: divides the left lobe into medial and lateral segments.

List the 2 normal hepatic vein flow features.

what is the normal direction ? and list 3 ways to describe the waveform?

• Hepatofugal flow

• Phasic, bidirectional/pulsatile waveform

Simple reminder:
Portal veins normally flow into the liver. Hepatic veins normally flow away from the liver.

The hepatic veins collect blood from the liver and “dump” it into the IVC, which then carries it to the right atrium of the heart.

List the 3 structures in the portal triad.

• Hepatic duct

• Portal vein

• Hepatic artery

Describe the relationship between portal veins and hepatic veins. - how do they run towards each other?

Portal veins and hepatic veins run perpendicular to each other.

When the portal vein is long, how does the hepatic vein appear?

When the portal vein is long, the hepatic vein appears transverse.

List the 2 basic liver functions. - most important

• Bile formation and secretion

• Detoxification

Bile formation and secretion:
The liver makes a liquid called bile. Bile helps your body break down and digest fats from food. The liver sends bile to the gallbladder, where it is stored until needed.

Detoxification:
The liver acts like a filter. It removes or changes harmful substances from the blood, such as alcohol, medicines, and waste, so the body can safely get rid of them.

List the a liver blood tests.

• Bilirubin

Bilirubin:
Bilirubin is a yellow waste product made when old red blood cells break down.

The liver takes bilirubin out of the blood, puts it into bile, and helps the body get rid of it through stool.

If bilirubin gets too high, the skin and eyes can turn yellow. This is called jaundice.

List the 4 patient/positioning techniques for liver duplex.

patients begins how?

name another position?

utilize what techniques?

you should change what?

• Patient begins supine.

• Use left lateral decubitus if needed.

• Utilize breathing techniques.

• Change windows

List the 3 imaging windows used for liver duplex.

• Subxiphoid

• Subcostal

• Intercostal

What transducer is used for liver duplex?

A curvilinear 2.0–6.0 MHz transducer.

List the 6 indications for a liver duplex exam.

• Hepatitis

• NAFLD / NASH - Non-Alcoholic Fatty Liver Disease

  ◦ NASH – old nomenclature

• Cirrhosis / ETOH abuse / portal hypertension

• Abnormal lab values

• Cancer

• Portal hypertension assessment

Cirrhosis:
Cirrhosis means the liver has become badly scarred and damaged over time. The scar tissue makes it harder for the liver to do its job and for blood to flow through it.

EtOH abuse:
“EtOH” means alcohol. Drinking too much alcohol for many years can repeatedly injure the liver, causing inflammation and eventually cirrhosis.

What is the protocol ?

The RUQ protocol first.

Grey Scale / Color Doppler / Spectral Doppler

Splenic vein – posterior to pancreas head

Portal vein : Main , Right , Left

Hepatic veins: Right , Main , Left

Grey Scale / Color Doppler / Spectral Doppler

Inferior Vena Cava

Color Doppler / Spectral Doppler

Hepatic artery : Main, common or proper , Right and left, & Collateral venous pathways if noted

Color Doppler and Spectral Doppler : SMV

What does shear wave elastography measure?

It measures the stiffness of liver tissue.

List the 4 patient histories where shear wave elastography may be performed.

• Elevated LFTs (liver function test)

• Hepatitis

• Cirrhosis

• NASH (Non-Alcoholic Fatty Liver Disease)

List the 7 technique points for elastography. (MAYBE SKIP?)

• Technique is vendor specific.

• Patient may be what list 2

• _____arm is placed over the ____.

• Use Couinaud segments 7 or 8.

• Sample at least ____cm from the liver surface.

• Choose an area free of structures such as _____.

• Apply ____pressure with the transducer.

• Technique is vendor specific.

• Patient may be supine or (Left Posterior Oblique).

• Right arm is placed over the head.

• Use Couinaud segments 7 or 8.

• Sample at least 1.0 cm from the liver surface.

• Choose an area free of structures such as vessels.

• Apply firm pressure with the transducer.

Should hold breathing, beacuse it affects the velocities and should be fasting becasuse it could affect the velocities of the stiffness of the liver)

How many elastography samples are taken?

10–12 samples are taken.

List the 4 GE liver fibrosis staging categories with m/s.

• Normal–mild:

• Mild–moderate:

• Moderate–severe:

• Cirrhosis:

what does red mean and what does blue mean?

• Normal–mild: 1.35–1.66 m/s

• Mild–moderate: 1.66–1.77 m/s

• Moderate–severe: 1.77–1.99 m/s

• Cirrhosis: >1.99 m/s

Red is fast flow stiff, blue is slower not as stiff - no vessels just the tissues

What values indicate no clinically significant fibrosis for Phillips/Siemens criteria?

and Clinically significant fibrosis / cirrhosis: METAVIR stage? and tell me the value of m/s ?

No clinically significant fibrosis is METAVIR stage <F2, or F0–F1, with values <1.37 m/s

Clinically significant fibrosis / cirrhosis: METAVIR stage > F4 (high end of F4) >2.2 m/s

List the 4 normal grayscale liver findings.

• Homogeneous liver

• Low-level echoes

• Smooth borders

• Intrahepatic vessels easily identified

What is normal portal vein flow direction?

Normal portal vein flow is hepatopedal, meaning flow is into the liver.

What Doppler angle should be used for the portal vein?

Doppler angle should be ≤60° and parallel to the flow state.

What should be measured in the portal vein?

Velocity should be measured.

Are portal vein velocities consistent?

No. Velocities are widely variable.

What is the normal MPV diameter in quiet respiration?

The MPV diameter should be <13 mm in quiet respiration.

What may an MPV diameter >13 mm suggest?

It may suggest portal hypertension.

Describe normal portal venous flow.

Normal flow is ______antegrade or retrograde flow with possible minor respiratory phasicity.

Normal flow is continuous antegrade flow with possible minor respiratory phasicity.

What can cause exaggerated portal venous pulsatility? List 2

Right heart failure or tricuspid regurgitation can produce exaggerated pulsatility.

How should the MPV diameter be measured?

Measure the portal vein diameter where it crosses _____to the ____during quiet respiration.

Want to sample as where of the liver as we can see it

Measure the portal vein diameter where it crosses anterior to the IVC during quiet respiration.

Want to sample as far outside of the liver as we can see it

What position should the patient be in for MPV diameter measurement?

The patient should be supine.

What waveform should normal hepatic arteries have?

They should have low-resistance waveforms.

What index should be obtained for hepatic arteries?

A resistive index, or RI.

What is the RI formula?

RI = (PSV − EDV) / PSV

Which approach / window is used for the proper and right hepatic artery?

The intercostal approach.

Which approach is used for the left hepatic artery?

The subxiphoid approach.

What waveform is seen at the hepatic vein confluence?

A “flying W” waveform.

What is normal hepatic vein flow direction?

Hepatofugal flow direction.

What waveform is seen in the IVC?

A “flying W” waveform.

What affects hepatic venous diameter?

Hepatic venous diameter varies with respiration.

List the 3 hepatic vasculature pathologies covered

• Portal hypertension, or PHTN

• Portal vein thrombosis, or PVT

• Hepatic vein obstruction

List the 4 abnormal liver grayscale findings

• Heterogeneous echotexture

• Nodular liver surface

• Increased echogenicity

• Intrahepatic vessels not easily identified

Liver surface is nodular:
This means the outside of the liver looks bumpy and uneven instead of smooth.

It happens because cirrhosis creates scar tissue. As the liver tries to repair itself, small lumps called nodules form.

Think of it like a smooth sponge becoming hard, scarred, and bumpy.

What fluid finding may be present?

Ascites may be present.

What spleen finding may be present?

The spleen may be enlarged. (because flow is backing into the spleen)

Explain what happens in portal hypertension at the sinusoid level.

____changes at the sinusoid level cause

list 2 things that changes, loses the ability to manage what? what develop?

Fibrotic changes at the sinusoid level cause resistance and pressure changes. The liver loses the ability to manage blood flow, and collateral pathways develop.

Sinusoidal level means the problem is happening in the liver’s tiny blood channels called sinusoids.

Sinusoids are like very small pathways where blood flows through the liver so the liver cells can clean and process it.

In cirrhosis, scar tissue squeezes these tiny channels, making it harder for blood to pass through. This causes pressure to build up in the portal vein, called portal hypertension.

List the 3 classifications of portal hypertension. & Which classification is most common?

• Extrahepatic

• Hyperdynamic

• Intrahepatic portal hypertension is most common.

These are three ways portal hypertension can happen:

Extrahepatic:
The blockage is outside the liver, such as a blood clot in the portal vein.

Hyperdynamic:
Too much blood is flowing into the portal system, so the pressure becomes high.

Intrahepatic — most common:
The problem is inside the liver. Cirrhosis and scar tissue make it difficult for blood to flow through the liver, causing pressure to build up.

Think of it like a traffic jam:

• Extrahepatic: the road is blocked before the liver.

• Hyperdynamic: too many cars are entering the road.

• Intrahepatic: the roads inside the liver are narrowed or blocked.

List the 6 effects of elevated pressure in portal hypertension.

• Ascites

• Splenomegaly

• GI / esophageal bleeding

• Jaundice

• Signs of hepatic failure

• Hepatic encephalopathy

GI – Esophageal bleeding:
This means bleeding in the digestive system from the esophagus, the tube that carries food to the stomach.

With portal hypertension, pressure builds up and causes veins in the esophagus to become enlarged. These enlarged veins are called esophageal varices.

Hepatic encephalopathy:
This happens when the liver cannot properly remove toxins from the blood.

The toxins build up and travel to the brain, causing problems such as:

• Think of the liver as a filter. When the filter is damaged, waste stays in the blood and affects the brain.

List the 2 portal flow directions used in PHTN evaluation.

• Hepatopedal: flow into the liver; normal state

• Hepatofugal: flow away from the liver - abnormal

Are velocities a good diagnostic parameter for PHTN?

No. Velocities are not a good diagnostic parameter.

What happens to portal vein size in PHTN? due to what?

Portal vein size increases due to elevated pressures.

Why is portal vein enlargement important?

It is a reliable sign for portal hypertension.

List the 2 types of extrahepatic portal hypertension.

• Prehepatic

• Posthepatic

List the 3 prehepatic causes of extrahepatic PHTN.

• Portal vein thrombosis

• Compression

• Stenosis

Prehepatic = before the liver

The blockage is in the portal vein before blood enters the liver.

Examples:

• Portal vein clot

• Portal vein narrowing

• Something pressing on the portal vein

So the blood is saying: “I cannot get into the liver.”

List the 3 posthepatic causes of extrahepatic PHTN.

• Hepatic vein or IVC thrombosis

• Compression

• Stenosis

Posthepatic = after the liver

The blockage is in the hepatic veins or IVC after blood passes through the liver.

Examples:

• Hepatic vein clot

• IVC clot or narrowing

• Something pressing on these vessels

So the blood is saying: “I entered the liver, but I cannot get out.”

What causes hyperdynamic PHTN? list 2

Arteriovenous malformations (AV fistula) or conditions that cause arterial portal fistulas.

Arterial-portal fistula

This is an abnormal shortcut connecting a high-pressure artery directly to the low-pressure portal vein.

Because arteries carry blood with more force, blood rushes into the portal vein and raises its pressure.

Think of it like connecting a powerful fire hose to a small garden hose. Too much water enters too quickly, so the pressure builds up.

So remember:

Hyperdynamic = too much blood entering the portal system.

List the 2 types of intrahepatic portal hypertension.

• Presinusoidal

• Postsinusoidal

List the 4 presinusoidal causes of intrahepatic PHTN.

• Hepatic fibrosis: Scar tissue forms in the liver and makes it harder for blood to pass.

• Sarcoidosis: Small clumps of inflamed cells form in the liver and can block blood flow.

• Schistosomiasis: A parasite causes inflammation and scarring around the liver’s small portal vessels.

• Lymphoma: Cancer of the lymphatic system can enter or press on liver tissue and interfere with blood flow

These are presinusoidal causes of intrahepatic portal hypertension. That means the problem is inside the liver but before blood reaches the tiny sinusoids.

These conditions narrow or block the small blood pathways before the sinusoids, causing portal pressure to build up.

List the 2 postsinusoidal causes of intrahepatic PHTN.

• Cirrhosis

• Veno-occlusive disease

Postsinusoidal means the blood-flow problem happens after blood passes through the liver’s tiny channels called sinusoids, but before it can leave the liver normally.

• Cirrhosis: Scar tissue makes the liver hard and squeezes the tiny blood channels, so blood has trouble moving through and out of the liver.

• Veno-occlusive disease: The tiny veins that carry blood out of the liver become narrowed or blocked.

Think of the sinusoids as tiny roads through the liver. In postsinusoidal disease, the exit side of those roads is blocked, so blood backs up and causes portal hypertension.

Explain how cirrhosis causes increased resistance to hepatic inflow.

4 things to list

Cirrhosis causes hepatocellular death, parenchymal degeneration and regeneration, and bridging fibrosis, which increases resistance to hepatic inflow.

(inflow are the portal vein and hepatic arteries)

• Hepatocellular death: Liver cells die from repeated damage.

• Parenchymal degeneration: The healthy working tissue of the liver becomes damaged.

• Regeneration: The liver tries to repair itself by growing new cells, but they grow in abnormal lumps called nodules.

• Bridging fibrosis: Thick bands of scar tissue form and connect different damaged areas, almost like bridges of scar tissue across the liver.

• Increased resistance to hepatic inflow: The scar tissue squeezes the tiny blood pathways, making it difficult for blood from the portal vein to enter and travel through the liver.

Think of the liver like a sponge. A healthy sponge has open holes that water can easily pass through. Cirrhosis fills those holes with hard scar tissue, so blood has trouble passing through and backs up, causing portal hypertension.

Explain how portal flow changes as PHTN progresses.

At first, increased portal pressure maintains portal venous volume. As sinusoidal resistance increases, it equalizes with portosystemic collateral resistance. Eventually, sinusoidal resistance becomes greater than collateral resistance, causing reversal of portal flow and diversion of flow to collaterals.

List the 2 types of portosystemic collaterals.

• Tributary collaterals

• Developed collaterals

What are tributary collaterals?

They are preexisting vessels that normally drain into the portal, splenic, and mesenteric venous systems.

What is the most prevalent tributary collateral?

The coronary vein.

What are developed collaterals?- They are vessels that are not normal tributaries but develop or recanalize in the setting of what?

What is the easiest developed collateral to identify?

What are developed collaterals?
Answer:
They are vessels that are not normal tributaries but develop or recanalize in portal hypertension.

Study Question:
What is the easiest developed collateral to identify?
Answer:
The umbilical vein.

What is another name for the coronary vein?

What varices are associated with the coronary vein?

What acoustic window is used to see the coronary vein?

What is another name for the coronary vein?
Answer:
The left gastric vein.

Study Question:
What varices are associated with the coronary vein?
Answer:
Esophageal varices.

Study Question:
What acoustic window is used to see the coronary vein?
Answer:
The left lobe acoustic window.

Where is the coronary vein seen?

Study Question:
What is the normal coronary vein diameter?

Study Question:
What is an early sign of PHTN in the coronary vein?

Where is the coronary vein seen?
Answer:
It is seen superior to the splenic artery and anterior to the celiac axis or posterior to the common hepatic artery or splenic artery.

Study Question:
What is the normal coronary vein diameter?
Answer:
It should not exceed 5–6 mm.

Study Question:
What is an early sign of PHTN in the coronary vein?
Answer:
Reversed flow is an early sign

List the 6 key features of the umbilical vein collateral.

• It is a remnant of ___circulation.

• It is located in the what.

• It courses from the ______to the anterior what vein.

• It normally measures ____.

• It may become numerous and tortuous.

• Recanalized veins have variable appearances. Straight, Serpiginous (crazy), multiple, single

• It is a remnant of fetal circulation.

• It is located in the ligamentum teres.

• It courses from the umbilicus to the anterior left portal vein.

• It normally measures <3 mm.

Study Question:
What happens to hepatic artery inflow in portal hypertension?

Study Question:
How can the hepatic artery appear in PHTN?

Study Question:
What happens to hepatic artery inflow in portal hypertension?
Answer:
Hepatic artery inflow increases substantially as a compensatory reaction.

Study Question:
How can the hepatic artery appear in PHTN?
Answer:
It may become enlarged and tortuous.

Can the hepatic artery fully compensate for the loss of portal flow?

No. It cannot adequately compensate for the loss of portal flow.

List the 2 hepatic vein effects of PHTN.

• Extrinsic compression with loss of pulsatility

• Size may not change with respiration