C L I N I C A L R O L E O F C O LORDOPP L E R IMAG I NG I N

C AROT I D S & P E R I PH ERA LAR T E R I E S

M . M a n t a t z i s , M D , P h D , E B N R

A s s i s t . P r o f o f N e u r o r a d i o l o g y

D e m o c r i t u s U n i v e r s i t y o f T h r a c e

General PrinciplesUltrasound for vascular Disease

�B – mode

� 2D Imaging

� Anatomical estimation

�Doppler

� Flow Estimation

� Continuous Wave (CW)

� Pulsed wave (PW)

• Color mode

• Spectral analysis

Doppler Phenomenon

�Sound frequency change when the examined object movesSound frequency change when the examined object movesSound frequency change when the examined object movesSound frequency change when the examined object moves

Terminology

�ΒΒΒΒ----mode + PW / Β/ Β/ Β/ Β----mode + CW = Duplex

�B-mode + PW + CW = Triplex

Duplex Triplex

Terminology

�Spectral WavesSpectral WavesSpectral WavesSpectral Waves

� Changes during Cardiac Cycle

�Low ResistanceLow ResistanceLow ResistanceLow Resistance

� Continuous flow during the whole cycle

�High resistanceHigh resistanceHigh resistanceHigh resistance

� Increased pulsatility – phasicity

� High resistance impedes flow during diastole � Stop or reversal of flow

� Normal

• Triphasic

• Biphasic

� Abnormal

• Monophasic

• Biphasic (when triphasic anticipated)

What about spectral?

Spectral terminology confusion�Triphasic flow Triphasic flow Triphasic flow Triphasic flow ���� ObviousObviousObviousObvious

�PandiastolicPandiastolicPandiastolicPandiastolic flowflowflowflow

� Biphasic or monophasic?

� In CAD literature � Biphasic

� In PAD literature � Monophasic

�Classic MonophasicClassic MonophasicClassic MonophasicClassic Monophasic

�TardusTardusTardusTardus ParvusParvusParvusParvus

Bidirectional flow

CLINICAL ROLE OF ULTRASOUND

For Cerebrovascular DiseaseFor Cerebrovascular DiseaseFor Cerebrovascular DiseaseFor Cerebrovascular Disease

• Prognosis oriented

• Prevent Cerebral infarction

– Estimate benefit from possible

intervention and natural history

• Role in asymptomatic patients

• Stenosis – plaque morphology

For Per ipheral a r ter ia l d i seaseFor Per ipheral a r ter ia l d i seaseFor Per ipheral a r ter ia l d i seaseFor Per ipheral a r ter ia l d i sease

• Symptom oriented

• Treat symptomatic disease– Claudication

– Pain

– Tissue loss

• Rx contraindicated for asymptomatic

• Stenosis

Τρόποι “εκµετάλευσης” του φαινοµένου Doppler

�ΣυνεχόμενοΣυνεχόμενοΣυνεχόμενοΣυνεχόμενο ΚύμΚύμΚύμΚύμαααα

�ΑδυνΑδυνΑδυνΑδυναμία διάκρισης του αμία διάκρισης του αμία διάκρισης του αμία διάκρισης του

σήμσήμσήμσήματος από αγγεία σε σειράατος από αγγεία σε σειράατος από αγγεία σε σειράατος από αγγεία σε σειρά

�ΠαΠαΠαΠαλμικόλμικόλμικόλμικό κύμκύμκύμκύμαααα

�ΑνάλυσηΑνάλυσηΑνάλυσηΑνάλυση φαφαφαφαινομένουινομένουινομένουινομένου από από από από τοντοντοντον

Ίδιοδιοδιοδιο κρύστκρύστκρύστκρύσταλοαλοαλοαλο

�PRF – Pulsed repetition Frequency

�Time Gating – Color wave

�Ανάλυσηνάλυσηνάλυσηνάλυση φάσμφάσμφάσμφάσματοςατοςατοςατος

C e r v i c a l v e s s e l s f o r B r a i n

General considerations - Clinical

�Symptomatic DiseaseSymptomatic DiseaseSymptomatic DiseaseSymptomatic Disease

� Last 6 months

• Hemispheric symptoms reversible within 24 h (TIA)

• Amaurosis fugax

• Ipsilateral stroke (subacute – chronic <6mo)

�Indication for emergency revascularization (CES/CAS)Indication for emergency revascularization (CES/CAS)Indication for emergency revascularization (CES/CAS)Indication for emergency revascularization (CES/CAS)

� Crescendo TIAs

� Progressive – Acute Stroke

US evaluation

�Β-modemodemodemode

� 3 distinct wall layers

• Hyperechoic– Mostly endothelium (intima)

• Hypoechoic – Mostly muscular – some outer wall (media)

• Hyperechoic –’Outer layer – perivascular (advenditia)

� Intima – Media Complex (IMT)

� Vertebral arteries cannot be evaluated in B-mode

Stenosis - What are we looking for?

StenosisStenosisStenosisStenosis Op riskOp riskOp riskOp risk Nat. HistoryNat. HistoryNat. HistoryNat. History Risk reductionRisk reductionRisk reductionRisk reduction pppp NNTNNTNNTNNT

<30% 6,7 10 -2,2% 0,05 -

30-49 8,4 18,2 3,2% 0,6 31

50-69 8,4 18,6 4,6 0,04 22

70-99 6,2 26 15,9 <0,001 6

Summary of results obtained in 6029 randomized patientECST (n=3018), the VA (Veterans Affairs) trial 309 (n=189), and the NASCET (n=2885)

W. Schäberle, Extracranial Arteries Supplying the Brain, in Ultrasonography inVascular Diagnosis - A Therapy-Oriented Textbook and Atlas, 2005

Treatment Recommendations

Clinical Presentation Clinical Presentation Clinical Presentation Clinical Presentation TreatmentTreatmentTreatmentTreatment

Not stenotic Plaques Asymptomatic or SymptomaticSymptomatic

Medical

Stenotic ICA Plaques Asymptomatic <70 %Asymptomatic >70 %

Symptomatic 50-70%Symptomatic >70%Stroke >70%

MedicalRevasc acceptable (?) only when perioperative risk <3%Revasc acceptableRevasc recommentedRevasc if sumptom resolution AND significant non-infarct territory

Occlusion Usually no Revasc

Flow evaluation

�ICA ICA ICA ICA – Vertebral arteryVertebral arteryVertebral arteryVertebral artery

� Low Resistance – Continuous flow

• Dynamic systolic increase

• Continuous diastolic flow

• Biphasic (?) Spectrum (or low-resistance)

�ECAECAECAECA

� Higher resistance

� Biphasic wave maintained (or triphasic ?)

�CCACCACCACCA

� Mixed Spectrum

Doppler Estimation of stenosis

Concentric lesions Vessel Diameter Cross Section Pre-stenotic V Post-stenotic V

6 113,0973355 60

3 (50%) 28,27433388 240

2 (66%) 12,56637061 540

2,4 18,09557368 375

�� � �� = �� � �� �� = �1 � �

�

Continuity LawContinuity LawContinuity LawContinuity Law: Flow rate (cross sectional area x velocity) remains constant

Diameter Reduction 50%

NASCETNASCETNASCETNASCET PSV ratioPSV ratioPSV ratioPSV ratio

50%

Χ4

75%

50%

Χ2

50%

Diameter reduction 66%

NASCETNASCETNASCETNASCET PSV ratioPSV ratioPSV ratioPSV ratio

66%

Χ9

>90%

66%

~ Χ3

65-70%

E . Grant, C. Benson, G Moneta et al, Radiology 2003

Plaque Morphology

�Flat Flat Flat Flat –––– fibrous plaquefibrous plaquefibrous plaquefibrous plaque

�Atheromatous Atheromatous Atheromatous Atheromatous –––– soft plaquesoft plaquesoft plaquesoft plaque

�CalcifiedCalcifiedCalcifiedCalcified

�UlcerativeUlcerativeUlcerativeUlcerative

�HemorrhagicHemorrhagicHemorrhagicHemorrhagic

�Supportive for borderline Supportive for borderline Supportive for borderline Supportive for borderline stenosesstenosesstenosesstenoses

Ultrasound Classification

�Type I: Type I: Type I: Type I: � Uniformly anechoic or hypoechoic

�Type II: Type II: Type II: Type II: � predominantly (>50%) hypoechoic

�Type III:Type III:Type III:Type III:� predominantly (>50%) hyperechoic

�Type IV: Type IV: Type IV: Type IV: � Uniformly hyperechoic

�Type VType VType VType V� Calcified plaque

Ελάττωση διαµέτρου 60%

NASCETNASCETNASCETNASCET ΛΟΓΟΣ ΤΑΧΥΤΗΤΩΝ

60%Χ6 (U=370cm/sec)U=370cm/sec)U=370cm/sec)U=370cm/sec)

>70707070%

60%X5 (U~250X5 (U~250X5 (U~250X5 (U~250----300 cm/sec)300 cm/sec)300 cm/sec)300 cm/sec)

>70>70>70>70%

Vertebral Artery Stenosis

�No Clinical trialsNo Clinical trialsNo Clinical trialsNo Clinical trials

�Possible Thromboembolism Possible Thromboembolism Possible Thromboembolism Possible Thromboembolism ���� same mechanism as CADsame mechanism as CADsame mechanism as CADsame mechanism as CAD

�Most common site the originMost common site the originMost common site the originMost common site the origin

� Difficulties in Evaluation

�Clinical role of USClinical role of USClinical role of USClinical role of US

� Raise the suspicion of significant Stenosis

• CTA, MRA, DSA

� Follow – up of VA Stenting

� Estimation of stenosis with Color Doppler

• Significant increase of PSV

Vertebral arteries

Kantarci et al, AJR 2006

Subclavian Stenosis – Steal Syndrome

P e r i p h e r a l A r t e r y D i s e a s e - P AD

~40%

PAD in lower extremities

~30%

~30%

LE PAD – Role of Ultrasound

�Chronic IschemiaChronic IschemiaChronic IschemiaChronic Ischemia

� Claudication

� Critical Ischemia - CLI

�Acute IschemiaAcute IschemiaAcute IschemiaAcute Ischemia

�Various DiseasesVarious DiseasesVarious DiseasesVarious Diseases

� Pseudoaneurysms

CHRONIC PAD

Fontaine Fontaine Fontaine Fontaine c lass i fcat ionc lass i fcat ionc lass i fcat ionc lass i fcat ion

• I Asymptomatic

• IIa Mild claudication

• IIb Moderate-severe claudication

• III Ischemic rest pain

• IV Ulceration or gangrene

Ruther ford c lass i f icat ionRuther ford c lass i f icat ionRuther ford c lass i f icat ionRuther ford c lass i f icat ion

• 0 Asymptomatic

• 1 Mild claudication

• 2 Moderate claudication

• 3 Severe claudication

• 4 Ischemic rest pain

• 5 Minor tissue loss

• 6 Ulceration or gangrene

PAD – Role of Ultrasound

� Clinical investigationClinical investigationClinical investigationClinical investigation

• Ankle – Brachial Index – ABI

– Normal >=1

�Ultrasound Ultrasound Ultrasound Ultrasound

� Confirm the clinical diagnosis

� Define level of obstruction

� Secondary

• Find critical stenoses

Ultrasound approach

�BBBB----mode in vessels near surfacemode in vessels near surfacemode in vessels near surfacemode in vessels near surface

� CFA

� Proximal SFA

� PopA – Prox ATA – DIST ATA,PTA – Dorsal Pedis

�Doppler Evaluation for Doppler Evaluation for Doppler Evaluation for Doppler Evaluation for StenosesStenosesStenosesStenoses

�Normal WaveformNormal WaveformNormal WaveformNormal Waveform

� Triphasic

• High resistance

• Vessel Elasticity

� Biphasic – monophasic

• In hypercirculation conditions

– Sympathetic stimulation– inflammation – fever – Hyperthyroidism

�Stenosis CriterionStenosis CriterionStenosis CriterionStenosis Criterion

� PSV Ratio >2 (Cross area reduction >50% � Significant stenosis)

�Post Post Post Post –––– stenotic stenotic stenotic stenotic abnormal Waveformabnormal Waveformabnormal Waveformabnormal Waveform

ULTRASOUND APPROACH

Critical Stenosis

Συµπτώµατα - Σηµεία

�Άλγος ηρεμίας

� Πόδι – δάκτυλα

� Δυσχέρεια ύπνου

�Ατροφία κνήμης

�Ψυχρότητα

�Έλκη

� Εντόπιση σε σημεία επαφής - βάρους

� δ/δ από νευροπαθητικά και φλεβικά έλκη

�Γάγγραινα

Occlusion

Acute Ischemia

�RareRareRareRare

�Embolic or acute thrombosisEmbolic or acute thrombosisEmbolic or acute thrombosisEmbolic or acute thrombosis

�Suggested bySuggested bySuggested bySuggested by

� Fairly hypoechoic – homogenous

� Good delination of the wall

� Preservation of smooth contour

� Absence of plaques

� Mostly in vessel bifurcations

Aneurysms

�True AneurysmsTrue AneurysmsTrue AneurysmsTrue Aneurysms

� Aorta – Popliteal arteries

� Saccular or spindle – shaped dilatations

� Usually Thrombosed

• Pseudo normal in DSA

Pseudoaneurysm

�Pseudo aneurysmsPseudo aneurysmsPseudo aneurysmsPseudo aneurysms

� Usually Iatrogenic

� Confined by tissues

� Color Doppler

� Yin Yang

� Ultrasound for diagnosis AND

treatment

FOLLOW UP

Conclusions

�Performance of vascular ultrasoundPerformance of vascular ultrasoundPerformance of vascular ultrasoundPerformance of vascular ultrasound

� Understanding of pathology

� Answer clinical questions

• Prevent stroke for CAD

• Treat symptoms for PAD

�Understand the ultrasound information in relation to clinical Understand the ultrasound information in relation to clinical Understand the ultrasound information in relation to clinical Understand the ultrasound information in relation to clinical

problemproblemproblemproblem

Thank you for

your attention

(Hopefully!!!)