Cerebro

• Abnormally High Velocities
• Extensive Plaque
• Probable Calcification
• Velocities May Approach Zero
• String Sign

No Flow

Turbulent

• 50% Diameter Reduction
• or
• 75% Cross Sectional Area Reduction

• Waveform Analysis
• Percent Stenosis: Diameter, Cross Sectional Area Reduction
• Color Flow
• VELOCITY

Velocity Measurements!

• Proximal CCA Has Higher Pulsatility
• CCA Has Reduced Diastolic Flow

Intra or Extracranially

• Waveform Distal Will Be Low Amp
• Dampened Wave
• Compensatory Flow
• (Overestimate Stenosis On That Side)

• % Stenosis = (1 - residual/original)x100
• % Stenosis = (1 - residual/distal)x100

• % Stenosis = (1 - residual^2/original^2)x100
• % Stenosis = (1 - residual1 x residual2 / original1 x original2)x100

• ICA Velocity/CCA Velocity = More Than 1
• ICA/CCA Ratio Of 1.8 = A 60% Stenosis

• Presence or Absence of Flow
• Direction of Flow
• Color Pattern - Changes in Saturation/Hue or Mosaic/Mottled Pattern Distal to a Stenosis
• Facilitates Visibility of Tortuosity/Bifurcations

Frequency shift, not velocity

Residual/Original

Residual/Distal

Carotid Endarterectomy (CEA) in good risk patients with ICA asymptomatic stenosis of 60-90%

Symptomatic patients with ICA stenosis of 70-90% diameter reduction treated with a combination of medical management and CEA

Each ultrasound department should develop their own doppler parameters for identifying high-grade carotid stenoses

• Highest within the stenosis
• Higher the velocity, higher the stenosis
• Once it reaches critical point of resistance to flow
• Decrease in velocity measurement here
• The length of lesion effects velocity
• Longer lesion, lower velocity

Less than 50% no significant pressure gradient = no significant velocity change

Greater than 50% develop pressure gradient = increased velocity in proportion to degree of luminal narrowing

Closer to 70%, the greater the increase

Highly reliable for detection of high grade stenosis

• Severity of post stenotic turbulence is proportionate to severity of the luminal narrowing
• Greater stenosis, greater spectral broadening 
• 70%+ very turbulent

• ICA stenosis 60-90%
• PSV > 260 cm/sec and EDV > 70 cm/sec

• ICA stenosis 70-99%
• PSV > 325 cm/sec or ICA/CCA ratio > 4.0

• Normal flow around 40 or 50 cm/sec for average old person
• Vessel diameters vary
• May be tortuous 
• Origin stenosis - reduced flow, damped
• Distal obstruction - lower velocities/more pulsatile
• Lower cardiac ejection lower velocities - bilateral

• Normal
• Hesitating - perform reactive hyperemia
• Alternating - perform reactive hyperemia
• Reversed - full transition

• Normal CCA contour
• Systolic Peak < 4.0 kHz or 125 cm/sec
• None/Minimal spectral broadening in decelerating phase of systole
• Window present

• Abnormal CCA contour
• Systolic peak < 4.0 kHz or 125 cm/sec
• None/minimal spectral broadening in decelerating phase of systole
• Window present

• Systolic peak < 4.0 kHz orr 125 cm/sec
• Spectral broadening throughout systole
• No window

• Systolic peak > 4.0 kHz or 125 cm/sec
• Marked spectral broadening
• Increased diastolic flow

• Systolic peak > 4.0 kHz or 125 cm/sec
• Marked spectral broadening
• Increased diastolic flow
• End diastolic > 4.5 kHz or 145 cm/sec

• Flow to zero or reversed
• No signal

First zero slope after systole is below midslope

First zero slope after systole is above midslope

• (VICA/VCCA) > 1.8 ... 60%
• (VICA/VCCA) > 3.7 ... 80%

• (VICA/VCCA) > 2.4 ... 60%
• (VICA/VCCA) > 5.5 ... 80%

to hurt, loss of function of a part

Patient should be seen annually

• Occurs when a false lumen develops beneath the intima of a vessel
• False channel extends for variable distance
• Elevates the intima
• Compromises the true lumen
• Thrombosis may form in false lumen

• Affect on flow depends on severity of luminal compromise
• Vessel may thrombose causing complete occlusion
• If not occluded, flow may be maintained through true or false lumen
• Spontaneous dissection usually past bulb

• Trauma - causing an intimal rip or tear
• Dissecting aneurysm of ascending aorta
• Spontaneous means that the true cause is not known

• Atherosclerotic disease - TIA/CVA
• Headache 
• Severe neck and scalp pain
• Sudden onset or cessation of bruit
• Horner's Syndrome - drooping of ipsilateral eyelid

• Malformation: defective formation, deformity, acquired during development
• Communication between artery and vein
• Uncommon occurrence
• True AVMs are considered CONGENITAL
• May be intracranial or extracranial
• Decrease in resistance to flow

• Fistula: abnormal tube like passage, created surgically and others occur as a result of injury or as congenital
• Single connection between artery and vein
• Caused by penetrating injury, aneurysm, infection, MANMADE (iatrogenic)

• Normal development of vascular system is altered
• Capillaries undergo changes
• Proper changes result in multiple or single AVMs
• Later stage has fewer AVMs
• May have tortuous channels
• May involve artery

• Symptoms vary with location and extent
• Focal epileptic seizures
• Hemiparesis
• Aphasia
• Amnesia
• Bruit

• Glaucoma
• Diplopia
• Headache
• Bruit (through eye)
• Surgery may not be possible

• Pulsating mass
• Port wine birthmark - increase in skin temp
• Venous engorgement
• Pain and swelling
• Disfigurement

• Increase in flow to feeding artery with dialation
• Reverse flow artery distal to AV
• Venous distension in distal vein
• Valvular incompetence
• Increased pulsatile flow in proximal vein
• Bruit loudest over site of AV communication
• Patient may have pulsatile tinnitus
• May feel thrill over area
• Causes an increase in cardiac output - enlarged heart and CHF

• Possible brain surgery - location, size, condition of AVM
• Endovascular microembolization - coils, embolic therapy

• Relatively rare - 600 annually
• Neoplasm - could be bilateral
• Occurs at bifurcation - carotid body size of grain
• Neural crest paraganglion cell hyperplasia
• Highly vascularized mass
• Mass may cause hoarseness
• May cause vocal cord or facial paralysis
• Patient may display Horner's syndrome

Consists of relatively small tumors, which are minimally attached to the carotid vessels - surgical excision is not difficult

Tumors are larger, with moderate attachments. These tumors may require a temporary intraluminal carotid shunt during surgery

Tumors are very large neoplasms that encase the carotid arteries and often require arterial resection and grafting

• Radiation therapy has not been successful for reducing or slowing tumor growth
• Bilateral in 5% of patients, 32% in families
• May lead to death
• Surgical resection treatment of choice

• Stenosis or occlusion of subclavian or innominate artery
• Results in reversal of flow patterns due to pressure gradient changes
• Atherosclerosis most common cause

• Vertigo
• Limb paresis
• Visual disturbances
• Ataxia
• Syncope
• UE limb claudication

• Reduces total cerebral blood flow by 18%
• Severely affects hemodynamics extracranially
• Patient is usually asymptomatic
• Three distinct collateral patterns: Reversed Vertebral (Most common), Reverse right vertebral and right carotid artery, antegrade right vertebral and retrograde right ICA/CCA

• Subclavian occlusion with reversed vertebral
• Total cerebral flow is decreased by 6% due to reversed vertebral and subsequent subclavian steal
• No surgery for asymptomatic patients

• Most labs consider 20mmHg pressure difference between brachial arteries
• Reactive hyperemia - pump ipsilateral cuff 20 mmHg above systole for 3 minutes, cuff is deflated while monitoring ipsilateral vertebral artery

• No steal - normal after RH no change
• Limited steal - after RH some flow reversal
• Latent steal - alternating before, mostly reversed after
• Completed steal - mostly before, totally reversed after

• Syncope
• Dysphasia
• Ataxia
• Dysarthria
• Facial sensory problems
• Claudication
• Muscle atrophy
• Skin changes
• Pain at rest

• Most common in renal arteries
• Found affecting ICA
• Known as string of beads

• Intimal fibroplasia
• Medial hyperplasia
• Medial fibroplasia - most common
• Perimedial dysplasia

• Lesions in mid to distal portion of cervical ICA
• May extend to skull
• May be confined to proximal ICA
• Rarely affects intracranial vessels
• May lead to spontaneous dissection of ICA

• Female most common - mid adult age
• May be for estrogen
• May be caused by stress on ICA with poor medial blood

• Localizing - TIA
• Nonlocalizing - dizziness and lightheadedness
• Expressive aphasia, blurred vision, roaring in ear, and vertigo
• Completed stroke
• Bruit in 75% or more
• May be hypertensive

• Usually bilateral - one side worse
• May have string of beads appearance
• May have atherosclerosis changes at bifurcation
• May have dissection
• Usually treated with anticoagulants
• May be treated with surgery
• Repaired with balloon

• Rare!
• Two types: Fusiform or Saccular
• Saccular is most common: at biurcation bilaterally

• Pulsating mass in neck
• Bruit
• May see bulge in neck
• Pain over area
• Cerebral ischemia may result, distal emboli
• Compression adjacent

• Carotid Body Tumor
• Peritonsillar abscess
• Lymph node or tumor
• TORTUOUS VESSELS
• Treatment = surgery

• Sharp angulation of vessel
• Not very common
• May cause cerebral insufficiency
• Affects one or more segments of the artery
• Creates stenosis
• Commonly occurs 2 - 4 cm above bifurcation!!!
• May be bilateral
• May be acquired (not congenital)

• Loss of vessel elasticity
• Atherosclerotic degeneration
• Subintimal disruption from plaque
• Artery elongates and folds
• Patients usually 50+ years old
• No surgery for asymptomatic patients

• More common than kink
• Usually bilateral
• May be congenital
• May worsen with age
• Benign condition
• No treatment necessary

• 50%
• Slight increase in spectral
• Disease is present
• Patient may be
• Need follow up at

• Velocity increases and flow decreases are not worthy of meaning or mention until a stenosis reaches 50% diameter reduction
• Vascular surgeons hemodynamically significant is when surgery is needed (80-99%)

• Greater than 50%
• Increase in velocity, due to stenosis
• Extensive
• PSV may be 2-3 times higher than normal
• Patient may be