Liver socrative and review

Question 1

The evaluation of the portal system includes the hepatic, portal, splenic veins, the hepatic arteries and what other vessels?

Answer 1

1. IVC
2. Aorta
3. Collaterals if they are seen, the most common we will see is the coronary vein. The teres is also common.

Question 2

If scanning the MPV from anterior window, would you expect the flow to be hepatofugal or hepatopedal?

Answer 2

Hepatopedal.

Question 3

Which of these waveforms has the higher resistance to flow? The right or the left?

Answer 3

The right side is the one with the higher resistance. The between the systolic and diastolic is higher.

Question 4

Greater than what AP measurement is considered dilated for the IVC?

Answer 4

2.5 cm
We should also look at compressibility and pulsatility

Question 5

Which type of portal hypertension, pre, post, or intrahepatic will result in splenomegaly?

Answer 5

All of these result in splenomegaly, all of these will blood will cause a back up causing the spleen to enlarge.

Question 6

What ultrasound finding may be present in the porta hepatis when there is portal vein thrombosis? (not in vein)

Answer 6

Cavernous transformation (a lot of small vessels will enlarge to try to get blood through)

Question 7

What are three pitfalls of portal thrombosis that a sonographer should account for when scanning?

Answer 7

1. Failing to detect flow (poor doppler angle)
2. Having an adequate scale for doppler
3. Some portal thrombus is anechoic

Question 8

How does the normal hepatic vein waveform change in the presence of increased right sided heart pressures?

Answer 8

1. Decrease in the S wave
2. IVC dilation

Question 9

What direction are the right and left portal veins after the insertion of a TIPs shunt?

Answer 9

Hepatofugal

Question 10

Define the terms “hepetofugal” and “Heaptopedal”

Answer 10

Hepatofugal means away from the liver and hepatopedal means towards the liver

Question 11

Describe the normal hepatic artery waveform

Answer 11

1. The normal hepatic artery waveform is monophasic and has low resistance
2. IT has fast acceleration to the PSC and the window is filled in due to the small diameter related to the sample volume
3. Resistive index is ranged 0.5-0.7

Question 12

What are three considerations a sonographer must make when assessing for portal vein thrombosis to not miss the diagnosis?

Answer 12

1. Thrombus can appear anechoic so an assessment with colour doppler is crucial
2. The low velocity of flow can be missed if Doppler scale settings are not appropriate
3. An inadequate doppler angle, especially from an anterior window, could demonstrate a vessel that does not fill or give inaccurate velocity data

Question 13

Name the secondary finding at the porta hepatis when portal vein thrombosis is present

Answer 13

Cavernous transformation is the appearance of tiny collateral vessels in the porta hepatis when the portal vein is thrombosed

Question 14

Based on this sagittal image of the left lobe of the liver, what is the most likely diagnosis?

Answer 14

This is an image of the LPV in sagittal, demonstrating recanalization of the umbilical vein through the ligamentum teres. This finding supports a intrahepatic cause of portal hypertension

Question 15

What is the most likely diagnosis based on this waveform obtained in MHV?

Answer 15

The s-wave is retrograde, or hepatopedal, and should have been below the baseline. This happens when the right side heart pressure increases and over filling of the right ventricle causes the blood to backup into the liver

Question 16

Explain why the doppler assessment and 2D measurement of the portal veins is best done with quiet respiration as opposed to deep inspiration

Answer 16

Deep inspiration can eliminate the subtle respirophasic changes that should be present in the normal portal vein waveform. Deep inspiration can also cause the portal vein to dilate and give falsely abnormal measurement

Question 17

Explain the portosystemic shunt that results in gastric varices

Answer 17

With portal hypertension, a common route for blood to take to bypass the liver is through the coronary vein (left gastric vein). The coronary vein dumps blood into the gastroesophageal collaterals which are not accustom to the volume of blood they are not receiving. The overload causes the vessels to dilate and form varices that can be potentially life threatening if they rupture

Question 18

Outline the early and late complications seen following the TIPS procedure

Answer 18

1. Early on, thrombosis is the complication seen with TIPS. If it is partial there will be a jet at the site of stenosis. If occluded, the portal velocities can be reduced
2. Later on, neointimal hyperplasia is the complication. The body exaggerates the healing process, leading to increased scar tissue that creates a stenosis or possibly an occulsion

Question 19

Explain the role of ultrasound for a liver transplant

Answer 19

1. Ultrasound is performed before the procedure to assess the anatomy and anatomosis sites of the vessels and biliary tree.
2. Within the first 34 hours, ultrasound is used to evaluate the vessel and look for complications like an increased RI of the Hepatic artery
3. Follow up studies are done to ensure that the organ is not regjected and that other post operative complications, such as, hematomas and abscesses are not present.