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Pathologies Carotid Doppler 4Vessels.
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CAROTID DOPPLERPart II
DR.MUHAMMAD BIN ZULFIQARPGR-1 FCPS SHL
Sonographic features of severe ICA stenosis
Significant visible plaque (≥ 70% diameter reduction)
PSV > 230 cm/sec
EDV > 100 cm/sec
ICA/CCA PSV ratio ≥ 4.0
Spectral broadening
Color aliasing despite high velocity scale (100 cm/sec)
Color bruit artifact in surrounding tissue of stenosis
High-pitched sound at pulsed Doppler
Stenosis of ECA
• PSV of ECA stenosis Minimal < 200 cm/sec
Moderate 200 – 300 cm/sec Severe > 300 cm/sec
• ECA/CCA systolic ratio* < 2 ≤ 50% Ø stenosis ≥ 2 ≥ 70% Ø stenosis
Isolated ECA stenosis not clinically significant
PART II
1. Vertebral Artery2. Pathologies other than Arteriosclerotic
Disease3. Effect of extra-carotid diseases
Vertebral artery course
V1
V0
V2
V3
V4
BA
VAs asymmetric in 75 % – Left dominant in 80 %
Posteriorly directed loop when exists C1 transverse process2 VAs unite to form basilar artery: collateralization
Ultrasound of normal vertebral vessels
Cephalad flow throughout cardiac cycle Low resistance flow pattern VA origin regularly seen by experienced sonographers Size: variable & asymmetric – Mean diameter 4 mm PSV: 20 – 40 cm/sec – <10 cm/sec potentially abnormal
Vertebral artery
Vertebral vein
May occasionally be seen adjacent to VA Flow caudad & nonpulsatile
Schematic Doppler waveforms of VA
High-resistance flow in vertebral artery
High-resistance flow
No diastolic component
Distal VA stenosis or occlusion
Hypoplastic vertebral artery
Differential diagnosis:
Dizziness
Unsteady walking
Correlation with symptoms
Route of flow in left vertebral steal
Subclavian steal phenomenon refers to steno-occlusive disease of the proximal subclavian artery with
retrograde flow in ipsilateral vertebral artery
Types of subclavian steal
Transient reversal of vertebral flow during systoleConverted to partial or complete by provocative
maneuver
Pre-steal or bunny waveform
Striking deceleration of velocity in mid or late systoleHigh-grade stenosis of subclavian rather than occlusion
Incomplete steal
Complete reversal of flow within vertebral artery
Complete steal
Vertebral to subclavian steal
Presteal
Incomplete steal
Complete steal
Compared to bunny in profile
Provocative maneuver in steal syndrome
Conversion of pre-steal waveform to more pronounced steal
following deflation of pressure cuff
Inflation of pressure cuff on arm for 3 min & rapid deflationBy exercising the diseased limb also cause provocation
Pre-steal More pronounced steal
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseasesFibromuscular dysplasia DissectionVasospasm Aneurysm & pseudoaneurysm
Arterio-venous fistula Arteritis: Takayasu – Horton Carotid body tumor Idiopathic carotidynia
Most common cause
Fibromuscular dysplasiaMiddle age women – Renal arteries – String of beads pattern
Alternating zones of vasoconstriction & vasodilatation for 3 – 5 cm
ICA frequently – VA less frequently
Usually bilateral
ICA
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseasesFibromuscular dysplasia DissectionVasospasm Aneurysm & pseudoaneurysm
Arterio-venous fistula Arteritis: Takayasu – Horton Carotid body tumor Idiopathic carotidynia
Most common cause
Carotid & vertebral dissection
• Spontaneous dissection Bleeding from vasa vasorum Most common ICA & VA (atlas loop)
Intramural hematomaPain – Stenosis – Horner
• Vascular injury Iatrogenic: puncture – surgeryCCAIntramural hematoma ± intimal tear
• Stanford A dissection Intimal rupture in ascending aortaCCA
Dissection of aorta & cervical arteries
Patho-anatomy
Intimal rupture with false lumenOpen or secondarily thrombosed
Aorta
External intramural hematomaLumen constrictionRare intimal rupture
Cervical
Spontaneous dissection of ICAAsymmetric wall hematoma – Lumen stenosis – Expansion to outside
Diagnostic criteria (one sufficient)
Intramural hematoma
Intimal rupture/double lumen
Distal stenosis or occlusion
Symptoms: acute pain, Horner,
Course: recanalization in few weeks
a Longitudinal color Doppler ultrasound (US) image of an acute dissection of the internal carotid artery (ICA) with the dissection of the lumen (arrowhead) demonstrating color flow. ICA large arrow, external carotid artery (ECA) long arrow. b An abnormal high-resistance spectral Doppler US waveform is demonstrated in the dissection lumen (arrowhead). ICA large arrow, ECA long arrow. c. On day 14, there is intramural thrombus formation (arrowhead) with no evidence of color Doppler US flow within the dissection false lumen. CCA star, ICA large arrow, ECA long arrow
Spontaneous dissection of VA
Wall hematoma in V1
Diagnostic criteria (one sufficient):
Intramural hematoma (asymmetric, not concentric)
Intimal rupture/double lumen (rare)
Double lumen in V2
Dissection of common carotid artery
Transverse view Longitudinal viewDetection of two lumina & dissection membrane
Dissection of CCA / Stenosis Residuum after end of aortic dissection
Doppler of true lumen
Enlargement of false lumen
before cranial end
Doppler of false lumen
Stenosis of true lumen
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseasesFibromuscular dysplasia DissectionVasospasm Aneurysm & pseudoaneurysm
Arterio-venous fistula Arteritis: Takayasu – Horton Carotid body tumor Idiopathic carotidynia
Most common cause
Vasospasm
• Causes Migraine, eclampsia, vasculitis, drug abuse, idiopathic
• Incidence Rarely identified (short duration) Occur frequently & remain undetected
• Symptoms Cerebral or ocular ischemia
• US Direct &/or indirect signs of severe stenosis Far above bifurcation – Sometimes bilateral Complete regression in hours to days – Relapse
• DD Dissection: wall hematoma – regression in weeks
• Treatment Calcium antagonists
Vasospasm Severe narrowing of ICA No stenosis detected
4 days later
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseasesFibromuscular dysplasia DissectionVasospasm Aneurysm & pseudoaneurysm
Arterio-venous fistula Arteritis: Takayasu – Horton Carotid body tumor Idiopathic carotidynia
Most common cause
Extra-cranial ICA aneurysmsColor Doppler US Power Doppler US
Incomplete delineation of aneurysm – Thrombi could not be excluded
Difficult definition for extracranial carotid artery aneurysmsdue to normal dilatation of bulb
ICA aneurysm / Parietal thrombosis
Aneurysm of proximal ICA
Parietal thrombus & homogeneous thickening of vessel wall
Longitudinal section Transversal section
CCA aneurysm / Rupture
CCA pseudoaneurysm / Rare
One month after bilateral neck dissection
CCA PseudoaneurysmLarge connecting neck
Color Doppler US CE multidetector CT
CCA PseudoaneurysmLarge connecting neck
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseasesFibro muscular dysplasia DissectionVasospasm Aneurysm & pseudoaneurysm
Arterio-venous fistula Arteritis: Takayasu – Horton Carotid body tumor Idiopathic carotidynia
Most common cause
Arterio-venous fistulaAttempt to perform US-guided jugular catheter insertion
Turbulent flow in fistula track High-velocity turbulent flow in track
Suspicion of communication between CCA & IJV
CCAIJV
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseasesFibro muscular dysplasia DissectionVasospasm Aneurysm & pseudoaneurysm
Arterio-venous fistula Arteritis: Takayasu – Horton Carotid body tumor Idiopathic carotidynia
Most common cause
Doppler ultrasound in arteritis“macaroni sign” & “halo sign”
• 2 types Takayasu Young female – SCA & CCAHorton Old female – SCA, AA & Temporal ACannot be differentiated using US
• US signs Macaroni Concentric hypoechoic wall thickeningHalo Dark halo around colorful lumenAll grades of stenosis – Thrombotic vessel
• DD Dissection Eccentric hypoechoic wall thickening Pronounced outward expansion
Takayasu’s arteritis Young female – SCA [‘pulseless’ disease] – CCA
CCA
Long hypoechoic wall thickening
Visualized in color Doppler as dark halo around vascular lumen
Horton's arteritis / Giant cell arteritis
Concentric hypoechoic wall thickeningSuperficial temporal artery
VA – Longitudinal view VA – Transverse view
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseasesFibromuscular dysplasia DissectionVasospasm Aneurysm & pseudoaneurysm
Arteriovenous fistula Arteritis: Takayasu – Horton Carotid body tumor Idiopathic carotidynia
Most common cause
Carotid body tumor / Rare
Histology Paraganglioma of low malignant potential
Presentation Palpable neck mass – Headache – Neck pain
US Highly vascular mass in carotid bifurcation
Arteriography Performed preoperatively – Embolization
Treatment Resection to prevent local adverse events: Laryngeal nerve palsy – carcinoma
invasion
Result Local recurrence 6% – Distant metastasis 2%
Carotid body tumor Highly vascular mass in carotid bifurcation
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseasesFibromuscular dysplasia DissectionVasospasm Aneurysm & pseudoaneurysm
Arterio-venous fistula Arteritis: Takayasu – Horton Carotid body tumor Idiopathic carotidynia
Most common cause
Diagnosis of idiopathic carotidyniaInternational Headache Society (IHS)1
• At least one of following over CA: TendernessSwellingIncreased pulsations
• Pain over affected side of neck that may project to head
• Appropriate investigations without structural abnormalityRecent publications demonstrate radiological findings2
• Self-limiting syndrome of less than 2 weeks duration
Idiopathic carotidynia
US findings comparable to dissection
Enhanced tissuearound carotid artery
CE T1-weighted MRIUS of distal CCA
Hypo-echoic soft tissuearound carotid artery
Three months later
Resolution of abnormalsoft tissue
Spontaneous dissection & carotidynia
Spontaneous dissection Carotidynia
Location Beyond bifurcation At or near bifurcation
Thickening layersOne wall layer 2 wall layers
Stenosis May be detectable Not detectable
Pain Head Neck
In unclear cases, MRI enables differentiation
Doppler US of carotid arteries
Anatomy of carotid arteries
Normal Doppler US of carotid arteries
Causes of carotid artery disease
Effect of extra-carotid diseases
Effect of extra-carotid diseases
• Idiopathic dilated cardiomyopathy
• Aortic regurgitation
• Aortic stenosis
• Stenosis of right innominate artery or origin of LCCA
• High & low PSV in CCA
• Stenosis of intra-cranial ICA
Idiopathic dilated cardiomyopathy
Pulsus alternans
PSV oscillating between two levels on sequential beats
Cardiac rhythm remains regular throughout
Aortic regurgitation
Bisferiens waveform [“beat twice” in Latin]
Two systolic peaks separated by midsystolic retractionDicrotic notch
Found also with hypertrophic obstructive cardiomyopathy
Severe aortic regurgitation
Normal or elevated PSV followed by precipitous declineRevered flow during diastole
Water-hammer spectral appearance
CCA
Aortic stenosisRCCA – Tardus Parvus LCCA – Tardus Parvus
RVA – Tardus Parvus
Right innominate artery stenosis RCCA – Tardus-Parvus LCCA – Normal waveform
RVA – Reversed flow
Right innominate artery stenosis
RICA : to-and-fro flow
RCCA : to-and-fro flow
RVA : reversed flow
RSCA : damped flow
Right carotid steal
High cardiac output: Hypertensive patientsYoung athletes
High flow > 125 cm/sec in both CCAs
Poor cardiac output: CardiomyopathiesValvular heart diseaseExtensive myocardial
infarction
Low flow < 45 cm/sec in both CCAs
Arrhythmias can be real problem
Normal PSV in CCA (45 – 125 cm/sec)
ICA
High-grade stenosis distally (intracranial ICA)
Major occlusive lesions of cerebral arteries (MCA, ACA)
Massive spasm of cerebral arteries from intracranial hemorrhage
Stenosis of intra-cranial ICAHigh resistance waveform
Advantages of power mode Doppler
• Angle independent
• No aliasing
• Increases accuracy of grading stenosis
• Distinguish pre-occlusive from occlusive lesions“detect low-velocity blood flow”
• Superior depiction of plaque surface morphology
Disadvantages of power mode Doppler
• Does not provide direction of flowNew machines provide direction of flow in power mode
• Does not provide velocity flow information
• Very motion sensitive (poor temporal resolution)
Causes of image/Doppler mismatch
• Cardiac arrhythmia• Severe aortic stenosis• Hypotension or hypertension• Tortuous vessels• Hypoechoic, anechoic or calcified plaques • Long segment high grade stenosis• Pre-occlusive lesion• Tandem lesion• Contra-lateral carotid stenosis• Carotid dissection
Limitations of carotid US examination
• Short muscular neck
• High carotid bifurcation
• Tortuous vessels
• Calcified shadowing plaques
• Surgical sutures, postoperative hematoma, central line
• Inability to lie flat in respiratory or cardiac disease
• Inability to rotate head in patients with arthritis
• Uncooperative patient
Thank You