Vasc. Duplex scan and color flow imaging in venous system Ch 30

what are some limitations with lower extrem venous exams

edema, collatorals, scarring, surgery, obesity, depth

what are some limitations that could lead to false positive of venous system

extrinsic pressure of tumor, pregnancy, or ascites
peripheral arterial disease affecting venous filling
COPD
Sonographer skill level

what should you do to color scale and gain to fill vein

decrease scale, increase gain

what position should pt be in for venous exam

reverse trendelenburg with knee turned out and slightly flexed

what probe is usually used for venous exam

7-12 MHz linear

what vein should be checked on asymptomatic side to look for inflow disease

CFV

where should imaging of LE peripheral veins begin

inguinal ligament

compression should be performed every — to — inches 

1-2 inches

why is no angle correction needed when dopplering venous system

we’re not measuring velocities

what is the primary criteria for detecting DVT

compression in transverse

what is secondary criteria for determining DVT

doppler signal in long

what is normal doppler signal of LEV

spontaneous flow, phasic

where are anterior tibial veins

anterolateral surface of tibia

where are posterior tibial veins

posteromedial to the tibia between medial malleolus and achilles tendon

where are peroneal veins

posteromedial to tibia, deeper than PTVs

what is CVI

chronic venous insufficiency

what are two parts of venous reflux testing

normal venous duplex exam - supine; and reflux - standing on stool

what will waveform look like if there’s venous reflux

will stay above baseline

what is a good way to scan small saphenous vein

from back of calf from pop to ankle

measure vein diameter of GSV and SSV in transverse with venous reflux testing

are peroneal or PTVs deeper

peroneal

what technique can be used to check for presense of venous reflux

valsalva or manually applying proximal and distal compression

what is timing to determine positive reflux in superficial or perforating vein

>500 ms (0.5 sec)

what is timing to determine positive reflux in deep veins

>1000 ms (1 sec)

what is normal transverse diameter measurement of GSV

4 mm

what is normal transverse diameter measurement of SSV

3 mm

what is normal transverse diameter measurement of perforators

<3 mm

what system settings should you adjust for optimal viewing of perforators

decrease scale and wall filter, increase gain

what is best patient position for perforators

standing

what are vericose veins caused from

standing, age, gender (pregnancy), family history, obesity

what is best position for peripheral UE veins

supine or low fowler (15-30 degrees)

where should imaging begin for UE venous 

internal jugular

what type of flow should subclavian vein have

borderline pulsatile since it’s so close to heart, not continuous

what techniques can be used to compress subclavian vein

pt taking quick breath w/pursed lips

what will compression of vein distal to transducer do to venous signal

increase

where should IVC and pelvic vein evaluation begin

level of umbilicus

where should venous study of other abd vessels begin

xiphoid process

what is normal portal vein flow

hepatopetal (toward, from splenic & SMV to liver), continuous flow, above base line, (barely/not phasic)

what is normal hepatic vein flow

hepatofugal (away from liver into IVC); bi directional, minimally phasic, or pulsatile may be seen

where should dopplers be taken of splenic vein

hilum, near SMV confluence posterior to pancreas

IVC and iliacs should dilate w/deep inspiration

in cases of congestive heart failure or fluid overload, what might a PV waveform look like

pulsatile

what flow do renal veins have

(blood to IVC) similar to hepatics: minimally phasic, bi directional, or pulsatile

what is normal IVC flow

phasic, bidrectional/pulsatile

what is time frame of acute thrombosis

1st 14 days after formation of thrombus (thrombus loosely attached, venous wall is inflamed)

what is sono of newly formed thrombosis

low level echos, may be virtually anechoic, veins distended to abnormally large size, spongy

where do most LE DVTs begin

deep calf veins

what is most common site for LE DVT

soleal sinuses

what is floating thrombus

only partially attached, stop compressions/augments, keep in litter

what might it mean if flow is not spontaneous in CFV, SFV, or pops

distal obstruction (toward trunk)

iwhat might it mean f flow is continuous, not phasic, in CFV, SFV, pops

proximal obstruction

what is normal CFV flow

what might it mean if flow increases during proximal compression

venous reflux

what is Rouleau flow

sluggish flow, may indicate prox issue - RBCs ‘rolled’ like coins

what is timing of chronic thrombosis

6 months after acute episode

what may chronic thrombosis to do valves

damage them w/thickend cusps that adhere to vessel walls and create refulx or venous stasis

what may reflux result in

vericosities, edema, skin thickening, discolorations, ulcerations

what will doppler look like with chronic thrombosis

lack of spontaneous flow and phasicity, absence of valsalva respons, poor augmentation

what are clinical symptoms of chronic venous insufficiency

chronic leg swelling, prominent calf and ankle, discoloration, ulcers in gaiter zone (shallow and irregular)

what will color flow imaging look like w/CVI (chronic venous insuf)

flow becomes retrograde - directional shift in color flow during compression (may start as blue, then go red)

what size perf vein is reflux

>3.5 mm

what is bud chiari syndrome

hepatic vein occlusion