Vascular Flashcards
ICA
internal carotid artery
CCA
common carotid artery
ECA
external carotid artery
VA
vertebral artery
what are the 3 layers of an artery?
intima (inner layer)
media (muscle & middle layer)
adventia (outer layer)
what arteries are routinely assessed with carotid US?
CCA, ICA, ECA & VA
TIA
transient ischaemic attack
- mini strokes
RIND
reversible ischaemic neurological deficit - longer lasting episode with full recovery within 3 weeks
CVA
cerebrovascular accident, stroke
TMB
transient monocular blindness - loss of vision in one or both eyes
amaurosis fugax
transient monocular blindness - loss of vision in one or both eyes
what are some contraindications for a carotid US?
recent neck surgery, thick muscular neck, unable to lie flat, calcified vessels
what are some indications for a carotid US?
TIA, RIND, CVA, TMB, dizziness, vertigo, synecope, headache, post-op surveillance, pulsatile mass, vertebral occlusive disease, follow-up progress of disease
whats the patient positioning for a carotid US?
patient is supine, head lying to either side, head up or down but head to be turned slightly away from the side being examined
patient preparation for carotid US?
document history & risk factors, explain procedure fully to patient, gain consent
Bif
bifurcation
What is the main technique for confirming patency of a vein in a DVT study?
compression
The squeezing of the calf muscle to push the venous blood through the vessel is called?
augmentation
Patients who are at high risk for developing deep vein thrombosis are:
those who have had major surgical procedures, metastatic disease, take oral contraceptives, dont move for long periods of time etc
Laminar flow is the type of flow thought to exist in many vessels. Which of the following statement is true: blood velocity is
fastest at the centre of the vessel & slowest at the vessel wall throughout the cardiac cycle
the primary concern regarding patients with deep vein thrombosis is:
PE - pulmonary embolism
PE
pulmonary embolism
What is the method used for distinguishing ECA from ICA on Doppler US?
TT - temporal tapping, tapping patient in the area of the temporal artery will cause a change in the spectral waveform of the ECA and not the ICA
How do you correct spectral aliasing doppler artefact?
increase the pulse repetition frequency or adjust the baseline
PRF
pulse repetition frequency
What is the most common venous study?
DVT - deep vein thrombosis scan
DVT
deep vein thrombosis
SFA
superficial femoral artery
SFV
superficial femoral vein
What does blood flow and colour doppler show on US?
the colour depends on the direction of the blood flow in relation to where the probe is positioned AND to what our scale is set to show
What will positioning your probe to create a 90 degree angle against the vessel?
will have almost zero signal, you wont actually get any of this information
How to fix the colour doppler if its not filling up properly?
adjust angulation of the probe and the colour doppler box so there is a signal 60 degrees or under, but could this area thats not filling up be pathology? could be plaque, make sure setting are set correctly
What is a common arterial study?
carotid US
what is a common venous study?
DVT studies for leg veins
EDV
end-diastolic volume
What is a spectral trace?
Using a very small sample box & place directing into the centre of a vessel to listen to the vessel over a period of time to get an idea of what the velocity is doing because of the doppler shift signal
Name 3 diseases/disorders that can present with similar symptoms to a DVT
renal failure (subcutaneous odema), cellulitis, superficial thrombophlebitis
What is the main differences between superficial and deep veins?
superficial veins lie above the muscular fascia layer, they do not directly return into the IVC so there is no threat of a travelling embolis
describe 3 US findings for a positive DVT
non-compressible vessel, thrombus inside vessel, no phasic flow or evidence of flow with augmentation
describe 3 methods a sonographer could use to determine if a vessel is an artery or a vein
compressibility, pulsatility, colour flow direction, assess for valves, wall thickness and echogenicity
What may have a triphasic flow with a high resistive waveform?
extremity artery
PSV
peak systolic volume
Deep veins include
they lie below the muscle fascia & they include: common femoral, superficial femoral, profunda femoris, popliteal, posterior tibial, peroneal, anterior tibial, calf veins
superficial veins include
they lie bw the muscle fascia & the dermis. theres heaps of superficial veins but we will image the long saphenous vein, and the short (small) saphenous vein. Other superficial veins will really only be imaged if clinically indicated
what alternative symptoms increase the risk for DVT?
raised d-dimer, recent long haul flight, pregnancy, known coagulation disorders, immobolisation, malignancy, oral contraceptives, recent trauma or surgery
common symptoms of DVT
acute calf pain with associated localised tenderness, heat and swelling, cellulitis & oedema
What are some indications for a DVT US?
assessing for DVT, assess STP or SVT, venous insufficiency or venous reflux, pre-operative mapping of LSV prior to bypass surgery, has DVT symptoms
contraindications for a DVT US
unable to perform compression due to patient pain, obese patients, unable to examine calf muscles due to overlying obstacles (plaster, bandages etc that cant be removed), unable to visualise illiac veins and IVC due to bowel gas
main method for confirming patency
compression - direct pressure applied to vein. with the transducer to collapse the vein
what is a thrombi?
a thrombus is the formation of a blood clot in the blood vessels or the heart from various elements of flowing blood. after a thrombus forms, part of it may detach to create an embolus that travels through the bloodstream to lodge at a peripheral site
what is a thromboembolism?
an embolus that has been dislodged and travelled through the bloodstream to occlude a smaller vessel.
US characteristics suggestive for a positive thromboembolism
echogenic material visualised within the vein, compression of the vein is limited, the colour moves around the echogenic material (if not fully occulsive), no flow identified if vein is fully occluded
US characteristics for an acute thrombus:
hypoechoic (almost invisible), poorly attached to the vein wall, spongy, dilating the vein wall (if vein is totally obstructed)
Us characteristics for a chronic thrombus:
appear more echogenic & heterogeneous, be adherent to the vein wall, contract the vein wall over time (if vein is totally obstructed), may be accompanied by large collateral veins nearby
