Chapter 27: Duplex/color flow imaging Venous Flashcards
Duplex of the venous system is used to
identify thrombosis
detect calf lesions
extrinsic compression vs intrinsic obstruction
eval soft tissue masses
detect venous incompetence
document re canalized channels of collaterals
to improve imaging for venous structures
adjust color scale to detect slower velocities
change wall filters
increase color gains
with chronic venous insufficiency what do you normally see
flow reversal with valsalva which indicates venous reflux
evaluation of chronic venous insufficiency
may use cuff inflation technique while scanning
with patient standing and bearing weight on the contralateral leg
cuff sizes for venous insufficiency testing
thigh - 19 x 40cm
calf 12 x 40cm
foot 12 x 40cm
rapid cuff inflator inflates
80 mmHg thigh
100 mmHg calf
120 mmHg foot
with cuff at thigh, doppler flow direction and peak velocities are assessed
cfv and saphenofemoral junction
with cuff at calf, doppler flow direction and peak velocities are assessed
PV and GSV
with cuff at foot
PTV evaluated
methods to identify venous reflux include
spectral analysis
color flow imaging
spectral analysis with chronic venous insufficiency
reversed venous flow lasting more than 30 seconds to 1 minute
color flow imaging and chronic venous insufficiency
color changed noted during prox compression maneuver or cuff deflation
ivc and pelvic vein eval begins at
level of umbilicus in transverse
eval of other abdominal vessels begins at
xiphoid process in transverse
normal lower extremity doppler venous signals
spontaneity- signal heard at all sites except PTVs
Phasisity varies with respiration
lower extremity phasicity
increase with expiration
decrease with inspiration
upper extremity phasicity
decreased with expiration
increases with inspiration
pulsatile venous flow can indicate
CHF
pulsatile flow is normal in which vessels
subclavian and innominate veins
with deep inspiration what happens to abdominal vessels
dilation
what vessels in abdomen have bi-directional pulsatile doppler signals
ivc
renal veins
hepatic veins
what vessels are minimally phasic with continuous doppler signals
portal vein
splenic vein
mesenteric vein
if flow is not spontaneous at the CFV FV and /or pop veins
an obstruction distal to or at that site is suggested
if flow is not phasic, but continuous
a proximal obstruction should be considered
