Beths color doppler lecture Flashcards
color map
hue is ________
color observed such as red, blue
color map
saturation is ____________
color concentration
(pale, deep)
color map
luminance is _________
color brightness
(dark, bright)
above baseline on color map means the blood is moving ____________
towards the transducer
Color below the black baseline
represent blood that is moving
____________ from the transducer.
away
The darker colors closest to the
baseline represent the blood
flowing with the __________ velocities.
lower
The lighter colors farthest from the
baseline represent the blood
flowing with the ___________ velocities.
higher
Low color Doppler settings will also
cause the color Doppler signal to
appear outside of the blood vessel.
This is called _____________.
color bleeding
increase color scale(PRF) to increase/decrease sensitivity
decrease
do you increase color scale(prf) to evaluate low flow
no you decrease it
things to do if not enough color is seen in vessels
increase color gain
decrease color scale
decrease sample box size
make sure box is not at 90 degree angle
color doppler energy is good to show __________
perfusion even at low flow states
where should the gate be for pulsed wave doppler
center of vessel, parallel to walls
The gate should be no larger than ____________ the size of the vessel.
1/3
should you have a smaller or larger gate for arterial waveform
smaller
how to image the rt and lt portal veins together
long or trans
subcostal or intercostal
notch position
trans
subcostal
8 oclock
how to find left portal vein w ligamentum teres
midline
sagittal
fan left(to patients right)
how to find right portal vein with branches
intercostal or subcostal
long or trans
notch position
intercostal
long
11 oclock
will look like Y
how to find main portal vein
subcostal or intercostal
long or trans
notch position
subcostal
long
10 oclock / 45 degree angle
Normal Portal Vein Flow
* Continuous/monophasic hepatopetal flow
* Normal flow velocity 20-30 cm/s
* Flow increases after eating which in turns
decreased HA flow
* Flow decreases when standing or exercising
what does a Pulsatile Portal Vein suggest?
- Liver disease (?PHTN)
- Heart problem (look at HV)
- Can also be seen in a normal patient
can you augment for portal vein?
yes. press abdomen to help fill the vein
What type of waveform is hepatic veins?
triphasic, biphasic, monophasic
triphasic
What type of waveform is portal vein?
triphasic, biphasic, monophasic
monophasic
A normal hepatic vein has hepatofugal flow in the systole and in diastole, but has a short period of hepatopetal flow that represents the atrial kick in
end diastole. This gives the hepatic veins a waveform that has a pulsatile “W” appearance
why is hepatic veins pulsatile
because of the proximity to the heart
what happens to hepatic vein flow form when liver disease exist
it becomes biphasic or monophasic
where should you place your gate for hepatic veins
within a couple centimeters from ivc
are arterial waveforms high or low resistance
can be either
these waveforms have a forward
flow in diastole with the signal
well above the baseline during
diastole.
low resisitance
organs like liver, brain, and kidneys
these waveforms have little to
no flow in the diastole and
possibly have reversed early
diastolic flow.
high resistance
feed muscular beds, distal
aorta, common femoral and
the external carotid arteries
what is Very important to image and
Doppler after a liver transplant
due to possible occlusion
and/or stenosis at or near the
anastomotic site
hepatic artery
Best place to Doppler the splenic vein is at the
____________.
pancreatic tail
SMA has a __________- resistance
waveform with NPO status
high
The spectral waveform
should be obtained with
the SMA in the
__________ scanning
plane.
longitudinal
Renal artery has a __________ resistance
waveform
* Place Doppler cursor
in center of vessel.
low
Renal veins have fairly
steady, minimally
____________ flow
phasic
When taking a PW Doppler sample of the splenic vein at the pancreatic tail the waveform should be above or below the baseline
above the baseline
When taking a PW Doppler sample of the splenic vein at the splenic hilum, the waveform should be above or below the baseline
below the baseline
The main portal vein begins at the
portal confluence
What two vessels unite to form the portal confluence?
The splenic vein and SMV
The portal confluence can be found
at the level of the pancreatic head
Portal vein blood flow towards the liver is
hepatopetal
Portal vein blood flow away from the liver is
hepatofugal
What three structures make up the portal triad
main portal vein, proper hepatic artery, common hepatic duct
The liver receives more blood from the hepatic artery or the portal vein?
Portal vein-70-75%, (Hepatic artery sends only 25-30%)
Which vessel supplies greater oxygen needs to the liver
portal vein 50-55% (proper hepatic artery is 45-50%)
What AP measurement is the upper limits of normal for the main portal vein
13mm
Intersegmental vessels of the liver
Hepatic veins (course between the lobes and segments, interlobar and intersegmental)
Intrasegmental vessels of the liver
The portal triad course to the center of each segment (intrasegmental)
What makes the portal triad walls more echogenic than the hepatic vein walls
The portal triad is encased by a fibrofatty sheath (Glisson’s capsule) giving it hyperechoic walls.
Hepatic veins typically display what type of Pulse Doppler waveform?
Triphasic
During pulse Doppler analysis of bloodflow, how is blood flow towards the transducer demonstrated during normal spectral analysis of a vessel?
above the baseline
During pulse Doppler analysis of bloodflow, how is blood flow away from the transducer demonstrated during normal spectral analysis of a vessel?
below the baseline
Can the right hepatic artery originate from the SMA instead of the proper hepatic artery?
Yes it can. Seen in 11% of patients. The replaced RHA will be seen posterior to the main portal vein instead of anterior to it.
Can the left hepatic artery originate from the left gastric artery instead of the proper hepatic artery?
Yes it can. Seen in 10% of patients.
Does the hepatic artery typically have a high resistance or low resistance Doppler waveform pattern?
Low resistance, however; in a post liver transplant, a high resistance hepatic artery waveform may suggest organ rejection
Portal systemic collaterals
venous collaterals that are created to connect the portal system to the IVC in order to bypass the liver
Gastroecophageal varices
Collaterals of the distal esophagus and gastric fundus. These collaterals may lead to life-threatening gastrointestinal hemmorhage.
Recanalized umbilical vein
A re-opening of the umbilical vein (ligamentum teres) to act as a collateral from the left portal vein to the epigastric veins to the IVC.
Splenorenal varices
Tortuous collateral veins seen between the splenic and left renal hilum. For this reason, Doppler of the splenic vein at the pancreatic tail is more accurate in portal hypertension cases than the splenic hilum.
Intestinal varices
Veins of retroperitoneal structures such as the colon, duodenum and pancreas anastomose with systemic tributaries.
rectal varices (hemorrhoids)
a collateral path in which the inferior mesenteric vein drains into the rectal veins which connect with systemic tributaries
physical signs of portal systemic collaterals
- dilated veins on anterior abd wall
- Caput Medusa- tortuous collaterals around umbilicus
- Hemorrhoids
- Ascites- fluid wav
