Ch. 7 Vascular Flashcards
What are the indications for an extracranial duplex exam
asymptomatic neck bruit TIAs stroke screening for surgery f/u after a stent ot carotid endarterectomy
How many bruits are related to high grade stenosis
1/3
What is an emboli
piece of plaque that breaks off
Neurological deficits that occur intermittently, lasting from several minutes to a few hours
TIA
When do symptoms for TIA resolve
within 24 hours
Fixed or permanent neurologic deficits
CVA or completed stroke
Neurological deficits that last between 24 and 72 hours
Reversible Ischemic neurological deficit (RIND)
Symptoms of Carotid Artery Lesions
paralysis
paresthesia on one side (opposite side of affected)
Dysphasia/aphasia
Amaurosis fugax
What is paralysis
focal weakness
What is paesthesia
numbness usually on one side of the body
What is dysphasia or aphasia
difficulty speaking
What is Amaurosis fugax
(same side as responsible carotid lesion) is a TIA of the eye that produces blindness “shade” being pulled down over one eye
Symptoms of vertebrobasilar Insufficiency
doziness
diplopia
ataxia
What is diplopia
double vision
What is ataxia
loss of full control of bodily movement
What does the physical exam require
bilateral blood pressures
palpation of pulses for strength and symmetry
auscultation for bruits
What transducer and frequency is used for this exam
linear 7-14MHz
Vessels should be evaluated in both transverse and longitudinal planes and with
b-mode imaging
color
spectral doppler
A mobile appearing white line echo in the CCA is most likely
reverberation artifact from the IJV
What does speckling indicate
bruit
What is pulsed wave spectral doppler used for
measure flow velocities
document waveform contours
Differences between the ICA and ECA
ECA has multiple branches /
ECA will oscillate with “temporal tap” /
ICA is larger /
ICA has a low resistance wave form
Where do you perform the “temporal tap”
superficial temporal artery anterior to the ear
The ECA spectral waveform will have a
high resistance waveform and low diastolic component
How does the ICA typically lay in relation to the ICA
posterior
ICA has a
low resistance waveform and high diastolic
Where is flow reversal located in the bulb
along outer wall of bulb
What indicates normal flow within the bulb
yin yang sign
Is velocity measurement needed on bulb
no
Documented for flow separation in bulb:
flow reversal
yin yang sign
Sweeo doppler sample volume from
CCA into proximal ICA
What is PSV
peak systolic velocity
What is EDV
end diastolic velocity
What does isonate mean
to image with ultrasound
Where do you place the transducer to evaluate the vertebral artery
anteromedial aspect of midneck on long axis
Where do you want to obtain doppler signal for subclavian artery
as far proximal as possible
What are a few pitfalls
vessels high/low in the neck /
patients with thick short necks /
beam steering and angle correction with different transducers
Normal B-Mode characteristics
smooth vessel walls /
intima media clearly visible /
lumen is anechoic
Where does plaque most commonly occur
CCA bifurcation
What are the early stages of plaque
appears as thickened areas of intima media layers /
fibrous cap may form between plaque and lumen
How is plaque usually classified
smooth, irregular, homogeneous, heterogeneous
What term is discouraged to use by a sonographer
ulcerated because it is diagnostic
What is homogeneous plaque
uniform appearance and low echogenicity (high lipid content)
What is heterogeneous plaque
mixed echogenicity (fatty material and calcium)