Abdominal Doppler Flashcards
What does pulsed wave doppler do?
- measures velocity of fluid in a vessel
- pos or neg doppler shift based on motion between media and transducer
What is Nyquist limit?
top limit of scale, max value wave can show
What is aliasing?
when top value of wave is over the Nyquist limit, shows on the bottom of the scale
What are indications for abdominal doppler?
- cirrhosis
- portal HTN
- portal vein thrombosis
- TIPS eval
- liver transplant
- Budd-Chiari
How should a normal splenic vein appear on doppler?
- tail toward transducer
- head away from transducer
- continuous flow
- low velocity
- above baseline
How should the hepatic artery appear on doppler?
- hepatopetal, pulsatile flow
- high velocity, ~100 cm/s
- above baseline
How should MPV appear on doppler?
- hepatopetal, monophasic flow
- low velocity, between 20-40 cm/s
- above baseline
- respiratory phasicity
How should LPV appear on doppler?
- monophasic flow
- above baseline
- divides into med & lat branches
- appears as red branch off MPV
How should RPV appear on doppler?
- monophasic flow
- below baseline
- divides into ant & post branches
- appears as blue branch off MPV
How do LHV, MHV, RHV appear?
- triphasic flow
- respiratory phasicity
- below baseline
What is the sono app of portal HTN?
- enlarged MPV diam (>13 mm)
- collaterals
- splenomegaly
- ascites
What is the doppler appearance of portal HTN?
- hepatopetal, slow hepatofugal
- low velocity, continuous flow
- bidirectional flow
- recanalized umb vein
- lack of respiratory variation
- decreased velocity, <20 cm/s, can increase w recanalized umbv
How can portal HTN be treated?
Transjugular Intrahepatic Portasystemic Shunt (TIPS)
- reduces PV pressure & variceal bleeding
- usually RPV to RHV or MHV
- doppler analysis req
What is the sono app of PV thrombosis?
- increased HA flow
- partial/total occlusion of MPV
- echogenic thrombus
- collaterals
What are the symptoms of PV thrombosis?
- asymptomatic (chronic)
- ascites
- splenomegaly
- GI bleed
- intestinal ischemia (acute)
What is the sono app of cirrhosis?
- best diagnosed with elasto
- nodular contour, coarse
- enlarged caudate, IVC compression
What is the doppler app of cirrhosis?
- MPV flow reversal
- low MPV velocity
- increased pulsatility
- turbulent color pattern
What does positive or negative doppler shift refer to?
The direction the blood flow of the vessel is moving in reference to the transducer, positive = toward
Where do we look at the wave form during pulse wave?
In the spectral window that shows up on spectral analysis
How should the gate be placed?
In the middle of the vessel in the section that you want to sample, should be parallel and match the angle of the vessel
What should you adjust before doppler?
Scale, baseline, color gain
What do we need to do with the gate for any artery?
use angle correct
Which vessels appears to travel away from the transducer at the porta hepatis?
RPV
Which vessels require a velocity measurement for a liver doppler exam?
MPV, HA
Venous flow is typically how many phases?
monophasic
Monophasic flow in an artery means
there is pathology
