Intracranial Cerebrovascular Evaluations: Transcranial Doppler Ultrasound and Transcranial Color Duplex Imaging

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VASCULAR TECHNOLOGY PROFESSIONAL PERFORMANCE GUIDELINES Intracranial Cerebrvascular Evaluatins: Transcranial Dppler Ultrasund and Transcranial Clr Duplex Imaging This Guideline was prepared by the

1 VASCULAR TECHNOLOGY PROFESSIONAL PERFORMANCE GUIDELINES Intracranial Cerebrvascular Evaluatins: Transcranial Dppler Ultrasund and Transcranial Clr Duplex Imaging This Guideline was prepared by the Prfessinal Guidelines Subcmmittee f the Sciety fr Vascular Ultrasund (SVU) as a template t aid the vascular technlgist/sngrapher and ther interested parties. It implies a cnsensus f thse substantially cncerned with its scpe and prvisins. The guidelines cntain recmmendatins nly and shuld nt be used as a sle basis t make medical practice decisins. This SVU Guideline may be revised r withdrawn at any time. The prcedures f SVU require that actin be taken t reaffirm, revise, r withdraw this Guideline n later than three years frm the date f publicatin. Suggestins fr imprvement f this guideline are welcme and shuld be sent t the Executive Directr f the Sciety fr Vascular Ultrasund. N part f this guideline may be reprduced in any frm, in an electrnic retrieval system r therwise, withut the prir written permissin f the publisher. Spnsred and published by: Sciety fr Vascular Ultrasund 4601 Presidents Drive, Suite 260 Lanham, MD Tel.: Fax: svuinf@svunet.rg Internet: Cpyright by the Sciety fr Vascular Ultrasund, 2017.

2 Intracranial Cerebrvascular Evaluatin s: TCD and TCDI 02/2018 ALL RIGHTS RESERVED. PRINTED IN THE UNITED STATES OF AMERICA. Intracranial Cerebrvascular Evaluatins: Transcranial Dppler Ultrasund and Transcranial Clr Duplex Imaging PURPOSE Transcranial Dppler ultrasund (TCD) and transcranial clr duplex imaging (TCDI) studies measure bld flw velcities and directin within prtins f the intracranial arteries. TCD and TCDI evaluate the anterir and psterir circulatin territries t assess and manage patients with cerebrvascular disease. Testing is ften perfrmed t detect and mnitr vasspasm after subarachnid hemrrhage and screen children with sickle cell disease fr strke risk. Additinally, these exams can identify intracranial stensis and cclusin. TCD can detect intracranial embli and assess vasmtr reactivity. APPROPRIATE INDICATIONS Cmmn indicatins fr perfrmance f this examinatin include, but are nt limited t: Screening children with sickle cell disease fr strke risk Identificatin and mnitring f vasspasm after subarachnid hemrrhage Detectin f intracranial arterial stensis r cclusin Assessment f cerebral vasmtr reactivity Supprt the clinical diagnsis f brain death Mnitring the effects f thrmblytic therapy in acute strke patients Evaluatin f extracranial stensis n intracranial hemdynamics Detectin f cerebral emblizatin Cntrast enhanced detectin f right-t-left cardiac/extracardiac shunts Intra-perative mnitring during cartid endarterectmy r crnary artery bypass graft prcedures CONTRAINDICATIONS AND LIMITATIONS Cntraindicatins and limitatins may include the fllwing: Inadequate acustic windws and/r pr patient psitining Restless r uncperative patients U.S. Fd and Drug Administratin (FDA) recmmends the pwer utput f the transducer be reduced t the lwest pwer that allws a cmplete rbital examinatin Remve cntact lenses prir t the exam Output pwer must nt exceed 10% f maximum emitted pwer r 17mW per cm2 r equivalent In emergent r critical care situatins, it may be difficult t perfrm a cmplete exam TCD/TCDI perfrmance during interventinal prcedures requires additinal precautins fr the examiner, due t the presence f radiatin Cpyright by Sciety fr Vascular Ultrasund, All Rights Reserved. Printed in the United States f America. 2

3 Intracranial Cerebrvascular Evaluatin s: TCD and TCDI 02/2018 PATIENT COMMUNICATION Prir t beginning the exam, the sngrapher r examiner shuld: Intrduce self and explain why the examinatin is being perfrmed and indicate hw much time the examinatin will take. Verify the patient s name and date f birth r utilize facility specific patient identifiers. Explain the prcedure, taking int cnsideratin the age and mental status f the patient and ensuring that the necessity fr each prtin f the evaluatin is clearly understd. Respnd t questins and cncerns abut any aspect f the evaluatin. Educate the patient abut risk factrs fr cerebrvascular disease (when apprpriate). Refer specific diagnstic, treatment r prgnsis questins t the patient's physician. Explain the necessity f and remve patient s eyeglasses, cntacts and/r headcverings. PATIENT ASSESSMENT Patient assessment shuld be cmpleted befre the evaluatin is perfrmed. This includes assessment f the patient's ability t tlerate the prcedure and evaluatin f any cntraindicatins t the prcedure. The sngrapher r examiner shuld btain a cmplete, pertinent histry by interview f the patient r patient's representative and review f the patient's medical recrd, if available. A pertinent histry includes: Previus cardivascular surgeries Current medicatins r therapies Presence f risk factrs fr cerebrvascular disease Presence f symptms f cerebrvascular disease Results f ther relevant diagnstic prcedures Review f prir examinatins t ensure the evaluatin duplicates prir imaging and Dppler parameters Verify the requested prcedure crrelates with the patient's clinical presentatin PATIENT POSITIONING Review patient psitining requirements fr the examinatin and determine patient s ability t maintain prper psitining fr all prtins f the exam: Sitting r supine psitin with head supprted r stabilized fr transtempral, rbital and sub-mandibular apprach Turned t side with neck flexed/chin tward chest t ptimize access t framen magnum fr sub-ccipital (transframenal) apprach Alternatively, the sub-ccipital exam can be perfrmed with patient in sitting psitin, arms crssed and supprted by stretcher r bedside table, head resting n arms s that neck is supprted and relaxed Patient shuld be kept awake thrughut the exam due t changes in CO2 during sleep which may affect velcities and result in misdiagnsis The TCD examiner shuld be psitined at the patient s head with arms supprted Cpyright by Sciety fr Vascular Ultrasund, All Rights Reserved. Printed in the United States f America. 3

4 Intracranial Cerebrvascular Evaluatin s: TCD and TCDI 02/2018 INSTRUMENTATION Equipment used fr TCD and TCDI is separate and distinct. The majrity f velcity reference standards fr intracranial studies were btained at a zer degree angle with nn-imaging TCD equipment. Decreased velcities and inferir penetratin are reprted when cmparing TCDI t TCD studies. Transcranial Dppler Ultrasund Equipment (TCD) Utilizes a single crystal MHz pulsed Dppler prbe Equipment and sftware specifically designed fr TCD applicatins Displays all data in real time including: Sample vlume, sample depth Time averaged maximum mean velcity Peak systlic velcity/end diastlic velcity Acceleratin time Pulsatility (PI) r resistive indices (RI) Dppler pwer utput and frequency Directin sensitive Dppler bld flw meter Bi-directinal Dppler wavefrm display Audible utput and permanent recrding f the spectral wavefrm Transcranial Clr Duplex Imaging Equipment (TCDI) Duplex imaging scanner with B-Mde, clr and spectral Dppler capabilities Utilizes a 1-5MHz transducer prbe Displays all data in real time including: Sample vlume, sample depth, Dppler angle Time averaged maximum mean velcity Peak systlic velcity /end diastlic velcity Acceleratin time Pulsatility (PI) r resistive indices (RI) Dppler pwer utput and frequency Directin sensitive Dppler bld flw meter Bi-directinal Dppler wavefrm display Visual display, audible utput and permanent recrding f the spectral Cpyright by Sciety fr Vascular Ultrasund, All Rights Reserved. Printed in the United States f America. 4

5 Intracranial Cerebrvascular Evaluatin s: TCD and TCDI 02/2018 EXAM PROTOCOL wavefrms with crrespnding B-Mde/Clr image TCD and TCDI studies fllw a standard imaging prtcl fr the examinatin. A cmplete evaluatin includes spectral Dppler analysis f all accessible prtins f the majr intracranial arteries. Velcities can be measured by autmatic tracing r manual cursr placement. Bilateral evaluatins are essential fr a cmplete evaluatin. Transcranial Dppler- Cmplete Examinatin Prtcl Bth TCD and TCDI include Spectral Dppler wavefrms frm the fllwing vessels and appraches t btain mean flw velcities (withut angle crrectin): Submandibular Windw: Distal cervical internal cartid arteries (ICA) Transtempral Windw: Terminal internal cartid arteries (TICA) M1 segment f the middle cerebral arteries (MCA) Shuld btain prximal, mid and distal measurements A1 segment f the anterir cerebral arteries (ACA) Anterir cmmunicating artery, if detectable (ACA) P1 and P2 segments f the psterir cerebral arteries Psterir cmmunicating arteries, if detectable (PCA) Transframenal/Subccipital Windw: Terminal vertebral arteries (VA) Prximal and distal segments f the basilar artery (BA) Orbital Windw: (may nt be apprpriate fr all patients) Ophthalmic Artery (OA) Cartid siphn Transcranial Dppler-Vasmtr Reactivity Prtcl Vasmtr reactivity testing is cmmnly rdered t evaluate cerebral reserve capacity in patients with unilateral cartid cmprmises and r basilar artery cmprmises. A MHz transducer is used t insnate the MCA s either bilaterally r unilaterally. The patient is then asked t hld his breath fr thirty secnds while the targeted artery is mnitred. A nrmal respnse is fr the mean flw velcity t reduce and then versht the baseline velcity as time expires and breathing resume. Many strke and TIA patients cannt hld their breath that lng s t test reserve capacity an injectin f acetlyzlimide (Diamx) can be used which takes abut 10 Cpyright by Sciety fr Vascular Ultrasund, All Rights Reserved. Printed in the United States f America. 5

6 Intracranial Cerebrvascular Evaluatin s: TCD and TCDI 02/2018 minutes t maximally dilate the arteries, r a tank f air with high pco2 can be inhaled t precipitate vasdilatin. This is the ultrasund versin f a perfusin study withut requiring a cntrast medium. Transcranial Dppler Embli Mnitring Prtcl Transcranial Dppler is the nly mdality that can detect and lcalize native embli in real-time. A blind pulsed-dppler transducer is fcused n the MCA and in many times fixed t a headband s the test is hands-free after set-up. Sme headbands have servmtrs inside them that allws fr remte steering f the prbe at the machine site. In 50-60% f strke patients bilateral MCA mnitring can be achieved. This can cut the exam time in half. Mnitring the basilar artery is difficult and generally dne with prbe-in-hand, recrding beats per vessel. Embli riginating frm ne artery will be lcalized t an ipsilateral cartid r vertebral surce. Embli riginating frm a cardiac surce will spew embli thrugh all the vessels targeted. M-mde spectral analysis can imprve the display f the mving embli as well as allw a calculatin f embli transit time. Testing always fllws a cmplete transcranial Dppler Study. Transcranial Dppler fr Detectin f Right-t-Left Cardiac Shunts One r bth MCA s can be mnitred with a MHz pulsed-dppler transducer. In the ut-patient lab an RN is brught in t set an IV line in preferably the brachial vein. On inpatient studies, the IV-line is already set reducing exam time. An agitated blus f 9 cc s saline and 1 cc f air is injected withut Valsalva. The number f embli are cunted flwing thrugh the target artery within 1 minute f the injectin. A secnd injectin is perfrmed with a maximum Valsalva maneuver perfrmed when the blus if halfway injected. The number f micrbubbles are cunted flwing thrugh the target arteries n this secnd maneuver. Since the patient is awake and participating many shunts will be detected that are missed by transesphgeal echcardigraphy. If the patient has n acustic access thrugh the tempral windw mnitring the basilar artery is a suitable alternative. A cmplete TCD study is recmmended befre the Bubble prvcatin t check fr mild intracranial stensis and native embli. Cpyright by Sciety fr Vascular Ultrasund, All Rights Reserved. Printed in the United States f America. 6

7 Intracranial Cerebrvascular Evaluatin s: TCD and TCDI 02/2018 DISTINCTIONS BETWEEN TCDI AND TCD EXAMSTranscranial Duplex Imaging (TCDI) TCDI cmbines real time B-Mde imaging f cerebral parenchyma with clr Dppler imaging and spectral Dppler analysis f the majr intracranial arteries. The standard examinatin prtcl includes bilateral assessment f the distal extracranial ICA, ACA, MCA, PCA, vertebral and basilar arteries. Primarily used t assess strke risk in children with sickle cell disease and t detect and mnitr vasspasm fllwing spntaneus subarachnid hemrrhage Mean flw velcities and ratis remain the primary criteria fr diagnsis f cerebrvascular disease Wavefrms btained at 2-5mm increments with a 3-6mm sample vlume size Spectral analysis includes peak systlic velcity, end diastlic velcity, systlic upstrke r acceleratin time, pulsatility index, and time-averaged maximum mean velcity Angle crrected flw velcities may be higher than nn-angle crrected flw velcities (shuld use a zer degree angle) Mst diagnstic standards are based n nn-imaging TCD studies Prvides accurate B-Mde and clr Dppler imaging f intracranial anatmy Gray scale imaging f bny landmarks r parenchymal abnrmalities lesser wing f the sphenid bne, petrus ridge f the tempral bne and cerebral peduncles Clr Dppler imaging f the majr intracranial arteries Shuld depict the ACA, MCA, PCA and vertebrbasilar arteries May detect intracranial aneurysms 6mm in size Limitatins cmpared t TCD remain: pr beam penetratin with lwer vessel detectin rates subptimal mnitring f embli r vasmtr reactivity testing Transcranial Dppler (TCD) TCD prvides spectral Dppler analysis f the majr intracranial arteries. Diagnstic criteria shuld be based n published studies r internally validated criteria. The majrity f reference standards were btained with nn-imaging TCD equipment. The standard examinatin prtcl includes bilateral assessment f the distal extracranial ICA, ACA, MCA, PCA, vertebral and basilar arteries. TCD can be used t assess strke risk in children with sickle cell disease and t detect and mnitr vasspasm fllwing spntaneus subarachnid hemrrhage. Cpyright by Sciety fr Vascular Ultrasund, All Rights Reserved. Printed in the United States f America. 7

8 Intracranial Cerebrvascular Evaluatin s: TCD and TCDI 02/2018 Prvides infrmatin related t intracranial stensis r cclusin and cerebral circulatry arrest. Gld standard t detect, lcalize and quantify cerebral emblism in real-time Useful fr mnitring thrmblysis f acute intracranial cclusins, detecting extracranial ICA stensis, cerebral micremblism, right-t left cardiac shunts and t assess cerebral vasmtr reactivity Mean flw velcities and ratis are the primary criteria fr diagnsis f cerebrvascular disease Wavefrms btained at 2-5mm increments with a 3-6mm sample vlume size Vessel identificatin is based n depth and directin f flw Spectral analysis includes peak systlic velcity, end diastlic velcity, systlic upstrke r acceleratin time, pulsatility index, and time-averaged maximum mean velcity Calculate mean flw velcity ratis Evaluate Dppler wavefrm characteristics Dcument randmly ccurring high intensity signals (HITS) assciated with emblic phenmenn Benefits f TCD when cmpared t TCDI: better beam penetratin and vessel detectin rates can quickly evaluate intracranial arteries t perfrm prvcatinal testing, mnitring f embli and vasmtr reactivity testing REVIEW OF THE DIAGNOSTIC EXAM FINDINGS The sngrapher r examiner shuld: Review data acquired during the exam t ensure a cmplete and cmprehensive evaluatin has been perfrmed and dcumented. Explain and dcument any exceptins r limitatins t the prtcl. Dcument any changes cmpared with previus exams. Recrd technical findings n a wrksheet r ther apprpriate methd (e.g., cmputer sftware), and classify results accrding t the labratry diagnstic criteria. Dcument the exam date, clinical indicatins, perfrming sngrapher and exam summary in patient s medical recrd. PRESENTATION OF EXAM FINDINGS The sngrapher r examiner shuld: Prvide preliminary results when necessary as prvided fr by labratry specific guidelines. Cpyright by Sciety fr Vascular Ultrasund, All Rights Reserved. Printed in the United States f America. 8

9 Intracranial Cerebrvascular Evaluatin s: TCD and TCDI 02/2018 Present recrd f diagnstic images, data, explanatins, and technical wrksheet t the interpreting physician. Interpretatin must be available within tw business days. Sngrapher and interpreting physician name must appear n the final reprt. Finalized/signed reprt shuld be available within fur business days. Alert vascular labratry Medical Directr r apprpriate health care prvider when immediate medical attentin is indicated based n departmental guidelines and prcedures. EXAM TIME RECOMMENDATIONS High quality, accurate results are fundamental elements f TCD and TCDI examinatins. A cmbinatin f indirect and direct exam cmpnents is the fundatin fr maximizing exam quality and accuracy. Indirect exam cmpnents include: Pre-exam activities: btaining previus exam data, initiating exam wrksheet and paperwrk, equipment and exam rm preparatin, patient assessment and psitining, patient cmmunicatin Pst-exam activities: exam rm cleanup, cmpiling and prcessing exam data fr preliminary and/r frmal interpretatin, and exam billing activities. Direct exam cmpnents include: Equipment ptimizatin and the actual hands-n, examinatin prcess. Cpyright by Sciety fr Vascular Ultrasund, All Rights Reserved. Printed in the United States f America. 9

10 Intracranial Cerebrvascular Evaluatin s: TCD and TCDI 02/2018 REFERENCES Aaaslid R. Cerebral Hemdynamics and Transcranial Dppler Training. Rmmer B, BellnerJ, Kngstad P, Sjhlm H. Elevated transcranial Dppler flw velcities after severe head injury: cerebral vasspasm r hyperemia? J Neursurg. 1996; 85: di: /jns Bulas DI, Jnes AM, Seibert JS, et.al. Transcranial Dppler (TCD) screening fr strke preventin in sickle cell anemia: Pitfalls in technique variatin. Pediatr Radil. Nvember 2000;30(11): di: /s Jnes AM, Adams RJ, Seibert JS, Nichls FT, et al. Cmparisn f transcranial Dppler and transcranial Dppler imaging in patients with sickle cell anemia. Pediatr Radil. July 2001;31(7): di: /s Slan MA, Alexandrv AV, Tegeler CH, et al. Assessment: Transcranial Dppler ultrasngraphy: reprt f the Therapeutics and Technlgy Assessment Subcmmittee f the American Academy f Neurlgy. Neurlgy. 2004;62: di: di.rg/ /wnl Alexandrv AV, Slan MA, Wng LK, et al. Practice standards fr transcranial Dppler ultrasund: part I-- test perfrmance. J Neurimaging. 2007;17: di: /j x Tpcuglu MA, Unal A, Arsava EM. Advances in transcranial Dppler clinical applicatins. Expert Opin Med Diagn. July 2010;4(4): di: / Alexandrv AV. Cerebrvascular Ultrasund in Strke Preventin and Treatment. 2 nd ed. Hbken, NJ:Wiley-Blackwell; ISBN: Purkayastha S, Srnd F. Transcranial Dppler ultrasund: technique and applicatin. Semin Neurl. 2012; 32(04): di: /s Alexandrv AV, Slan MA, Tegeler CH, et al. Practice Standards fr Transcranial Dppler (TCD) Ultrasund. Part II. Clinical Indicatins and Expected Outcmes. J Neurimaging. 2012;22: di: /j x Jawad N, Kk Hi Y, Gulraiz A, Jnathan G. Transcranial Dppler Ultrasund: A Review f the Physical Principles and Majr Applicatins in Critical Care. Int J Vasc Med. Vlume 2013 (2013), Article ID Cpyright by Sciety fr Vascular Ultrasund, All Rights Reserved. Printed in the United States f America. 11

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