CurrentAetnaPolicy 0353

Transcranial Doppler Ultrasonography

Defines Aetna's medical necessity and investigational indications for transcranial Doppler ultrasonography and lists associated CPT and ICD-10 codes; applies to clinical use decisions for covered members and ordering providers.

Policy Summary

PayerAetna

PolicyTranscranial Doppler Ultrasonography

Policy CodePolicy 0353

Change TypeNo material changes

Effective DateSep 13, 1999

Next Review DateApr 11, 2024

Key ActionDocument that the indication meets a listed medically necessary reason and include an appropriate ICD-10 diagnosis when submitting covered CPT codes.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

13medically necessary indications

23experimental/investigational examples

4covered CPT codes

06/05/2023last review

Coverage Criteria for Transcranial Doppler Ultrasonography

inv-01: Medically Necessary Indications

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Covered when ANY of the following indications are present:

Medically necessary TDU indications: 1. Assessing collateral blood flow and embolization during carotid endarterectomy; 2. Assessing patterns and extent of collateral circulation in persons with known regions of severe stenosis or occlusion, including persons with Moyamoya syndrome; 3. Assessing persons suspected of having patent foramen ovale/paradoxical embolism (symptoms include visual disturbance, weakness, hemiplegia, or slurred speech); 4. Assessing persons with suspected brain death; 5. Assessing stroke risk of children (2 to 16 years of age) with sickle cell anemia (re-screening approximately every 6 months may be considered); 6. Detecting arteriovenous malformations (AVMs) and studying their supply arteries and flow patterns; 7. Detecting noncardiac right-to-left shunts; 8. Detecting microemboli in cerebral artery embolism following stroke or transient ischemic attack; 9. Detecting severe stenosis in the major basal intracranial arteries for members who have neurological signs or symptoms or carotid bruits; 10. Diagnosing and monitoring reversible cerebral vasoconstriction syndromes; 11. Diagnosing dissection of vertebral artery; 12. Evaluating and following persons with vasoconstriction of any cause, especially after subarachnoid hemorrhage; 13. Evaluating very low birth weight preterm infants with gestational age less than 30 weeks.

List taken verbatim from policy

inv-02: Experimental and Investigational (Not Covered)

Considered experimental and investigational for ALL other indications including, but not limited to:

Experimental/Investigational indications: Assessing autoregulation, physiologic, and pharmacologic responses of cerebral arteries; Brain tumors; Diagnosing cerebral vein and sinus thrombosis and other venous pathology; Diagnosing or monitoring response to antithrombotic therapy in ischemic cerebrovascular disease; Epilepsy; Evaluating adults with sickle cell anemia; Evaluating ataxia, head trauma/skull fracture; Evaluating children with neurofibromatosis; Evaluating neurocognitive disorders (e.g., depression); Evaluating dilated vasculopathies such as fusiform aneurysms; Familial and degenerative diseases of the cerebrum, brainstem, cerebellum, basal ganglia and motor neurons (e.g., Parkinson’s disease); Following placement of an intra-cerebral arterial stent; Guiding targeted adjunctive therapy in cerebral malaria; Infectious and inflammatory brain conditions; Managing traumatic brain injury; Migraine headaches; Monitoring brain injuries in individuals with left ventricular assist device; Monitoring during cardiopulmonary bypass and other surgical procedures other than carotid endarterectomy; Predicting hemorrhagic transformation of ischemic infarction; Predicting outcome in vertebrobasilar distribution stroke; Psychiatric disorders; Screening for carotid artery stenosis in asymptomatic adults; Screening for stenosis of cerebral arteries in persons with fibromuscular dysplasia.

Policy lists numerous non-covered investigational uses

inv-03: Established / supported clinical uses

TCD is considered clinically useful/established for the following indications when performed by qualified personnel:

Established indications: 1) Screening children aged 2–16 years with sickle cell disease for stroke risk; 2) Detection and monitoring of angiographic vasospasm after aneurysmal subarachnoid hemorrhage; 3) Assessment of cerebral vasomotor reactivity and autoregulation; 4) Documentation of circle of Willis functional status; 5) Identification of cerebral hypo- and hyper-perfusion, recanalization and re-occlusion; 6) Detection of cerebral emboli (microembolic signals); 7) Detection of right-to-left cardiac shunts via bubble study as a noninvasive screening test.

Supported by AAN, ASNM/ASN guidance and systematic reviews; TCD-BS shown safe and accurate for RLS in multicenter studies.

inv-04: Limited or uncertain utility / supplemental

TCD may provide useful information but has limitations or uncertain clinical impact for these indications:

Emerging or comparative utility: Intracranial steno-occlusive disease evaluation (value relative to MRA/CTA uncertain); cerebral circulatory arrest adjunct; monitoring thrombolysis for acute MCA occlusion (data limited); monitoring during carotid endarterectomy and coronary artery bypass grafting for emboli/flow changes (clinical impact unclear); vasospasm after traumatic subarachnoid hemorrhage; evaluation of basilar artery stenosis or in-stent restenosis (variable sensitivity/specificity; TCCS may be promising but requires larger studies).

Comparative accuracy vs imaging modalities often insufficient to replace angiography.

inv-05: Not routinely appropriate / investigational

Uses not routinely supported or of limited appropriateness:

Not routinely appropriate / investigational: Evaluation of ataxia and head trauma: ACR appropriateness criteria rate TDU as usually not appropriate; Use for Parkinson disease diagnosis remains investigational/adjunctive and not established as sole diagnostic test; TCD/TCCS is not sufficiently sensitive to exclude cerebral venous thrombosis and should not be the sole diagnostic test.

These settings may lead to non-coverage when used as primary diagnostic test without corroborative studies.

inv-06: Use in Acute Ischemic Stroke (AIS) / Suspected Large Vessel Occlusion

Evidence-based considerations for diagnostic use of TCD/TCCD in AIS:

AIS TCD/TCCD utility: TCD or TCCD may provide useful diagnostic information for detecting intracranial artery stenosis or occlusion, particularly MCA occlusion, when performed by experienced operators and within early time windows; can guide need for further vascular imaging where CTA/MRA are not immediately available.timing within 24 hours of symptom onset (some analyses better within 6 hours)

Summary sensitivity and specificity reported at ~95% each in a systematic review (9 studies, n=493) though heterogeneity exists; performance more consistent for MCA occlusion.

inv-07: Use for Micro-embolus Detection in Carotid Disease

Clinical considerations for MES/HITS detection by TCD:

MES as risk stratifier: Detection of micro-embolic signals (MES) by TCD has been shown to stratify stroke/TIA risk in patients with carotid atherosclerosis and may identify asymptomatic patients at higher risk who could benefit from intervention; increasing the positivity threshold to 10 MES/hour improves peri- and post-operative clinical usefulness. Example post-test probabilities: at 3% pre-test probability, positive TCD raises post-test to ~7.1% and negative to ~1.2%.10 MES per hour (positivity threshold improves specificity)

Meta-analysis and prospective studies support MES as a prognostic marker.

inv-08: Use for Basilar Artery Stenosis / In-stent Re-stenosis

Performance considerations from small studies:

Basilar artery assessment: TCD correlation with angiographic basilar artery stenosis is weak (Spearman rho≈0.35); ROC AUC ≈0.70 with sensitivity ~74% and specificity ~65% at PSV 124 cm/s. TCCS showed promising, but sample-limited, results for in-stent restenosis (reported AUC 1.00 using PSV 132 cm/s in a very small sample).PSV cut-offs reported: 124 cm/s and 132 cm/s

Authors concluded TCD validity was poor for basilar artery stenosis; TCCS requires larger validation studies.

inv-09: Use in Cerebral Malaria (Pediatric)

Phenotyping and prognostic associations identified by TCD:

Cerebral malaria TCD phenotypes: Distinct TCD flow phenotypes (hyperemia, low flow, microvascular obstruction, vasospasm, posterior hyperemia) were observed in children with cerebral malaria and were associated with different neurologic outcomes (e.g., low flow associated with higher mortality; vasospasm associated with survival with sequelae).Serial daily monitoring through hospital day 8 or until discharge/death

Authors suggest phenotypic grouping may guide targeted adjunctive therapies but recommend further validation.

inv-10: Monitoring in LVAD Patients

TCD for emboli monitoring and autoregulation:

LVAD monitoring: Transcranial Doppler embolus monitoring (TCD-e) has been used in patients with left ventricular assist devices; pooled observational data reported thromboembolic events in ~20% of patients and detected MES in ~27%; ischemic stroke prevalence was higher in patients with MES (43% vs 13%).None specified

Evidence is observational with heterogeneity in timing and protocols; combining serial TCD-e with LDH monitoring may be informative.

Use of transcranial Doppler ultrasonography (TDU/TCD) for indications listed in the policy’s experimental and investigational section is considered not covered. Examples include assessing autoregulation or pharmacologic responses, brain tumors, cerebral vein and sinus thrombosis, monitoring antithrombotic therapy, epilepsy, evaluation of adults with sickle cell anemia, neurocognitive or psychiatric disorders, migraine, many degenerative central nervous system diseases, guiding adjunctive therapy in cerebral malaria, monitoring during most surgical procedures (other than carotid endarterectomy), and other uses enumerated in the policy. Requests for TDU for these indications are subject to denial when submitted as primary justification for the test.

Transcranial Doppler (TCD/TCCS) is not sufficient as the sole diagnostic test to exclude conditions such as cerebral venous thrombosis or to evaluate head trauma/skull fracture. Ultrasonographic techniques may complement other imaging, but they are not sensitive enough to exclude cerebral venous thrombosis; the ACR appropriateness criteria rate TDU as usually not appropriate for head trauma/skull fracture.

Current UpToDate reviews of malaria management do not list transcranial Doppler as an established management tool, and the policy therefore does not consider TCD a standard of care for guiding targeted adjunctive therapy in cerebral malaria.

Clinical Policy Bulletins are developed to assist in administering plan benefits but are not offers of coverage and contain only a partial description of plan or program benefits; they do not constitute a contract or medical advice and may be updated.

Screening for carotid artery stenosis in asymptomatic adults and use of TCD for many neurologic, psychiatric, or degenerative conditions (examples listed in the non-covered ICD-10 codes and in the investigational section) are not supported by this policy and are considered non‑covered or investigational uses.

TCD provides physiologic flow information but should not replace anatomic imaging modalities required for procedural planning or interventions. When precise anatomic detail is required (e.g., for transcatheter PFO closure, intracerebral stent planning, or other endovascular procedures), confirmatory imaging such as TEE, CTA, MRA, or angiography is indicated rather than reliance on TCD alone.

For assessment of basilar artery stenosis, the policy notes that correlation between TCD-derived velocities and angiographic stenosis is weak and diagnostic performance is variable; authors have concluded that TCD validity for basilar artery stenosis is poor and therefore TCD alone is insufficient for definitive decision-making. Small studies suggest TCCS may be promising, but larger confirmatory studies are needed.

Coding — CPT and Diagnosis Codes

Covered CPT Codes (if selection criteria met)CPTCovered

93886	Transcranial Doppler study of the intracranial arteries; complete study
93888	Transcranial Doppler study; limited
93890	Transcranial Doppler vasoreactivity study
93892	Transcranial Doppler emboli detection without intravenous microbubble injection
93893	Transcranial Doppler emboli detection with intravenous microbubble injection

Other related CPT codesCPT

61635

Transcatheter placement of intravascular stent(s), intracranial (eg, atherosclerotic stenosis), including balloon angioplasty, if performed

ICD-10 Codes Listed as Covered (select examples)ICD-10

D57.00 - D57.819	Sickle-cell disorders [for evaluating children]
G93.1	Anoxic brain damage, not elsewhere classified
G93.5	Compression of brain
H34.00 - H34.9	Retinal vascular occlusions
H53.10	Unspecified subjective visual disturbances
H53.121 - H53.129	Transient visual loss
H53.131 - H53.139	Sudden visual loss
I28.0	Arteriovenous fistula of pulmonary vessels [for detecting noncardiac right-to-left shunts]
I60.00 - I65.9, I67.0 - I69.998	Cerebrovascular diseases
I74.9	Embolism and thrombosis of unspecified artery [paradoxical embolism]

1–10 of 25

1/3

ICD-10 Codes Not Covered / Not Indications (examples)ICD-10Not Covered

B50.0	Plasmodium falciparum malaria with cerebral complications
C71.0 - C71.9	Malignant neoplasm of brain
G40.00 - G40.919	Epilepsy and recurrent seizures
G43.001 - G43.919	Migraine
I77.3	Arterial fibromuscular dysplasia
Z13.6	Encounter for screening for cardiovascular disorders [screening for carotid artery stenosis in asymptomatic persons]

TCD velocity for high stroke risk in sickle cell disease — TAMM ≥ 200 cm/sec

TAMM thresholdTime-averaged mean velocity (TAMM) ≥ 200 cm/sec indicates high stroke risk in children with sickle cell disease (used to identify candidates for chronic transfusion).

Age groupScreening applied to children approximately 2–16 years of age per STOP trial and guideline recommendations.

Clinical consequenceElevated TAMM (≥200 cm/sec) in STOP trial cohort led to chronic transfusion that reduced stroke risk by >90%.

Basilar artery PSV cut-off for ≥50% stenosis

Basilar PSV cut-off (≥50% stenosis)Optimal cut-off of peak systolic velocity (PSV) 124 cm/s for detection of ≥50% basilar artery stenosis (Youden-index derived).

TCCS in-stent restenosis cut-offFor TCCS assessing in‑stent restenosis, PSV 132 cm/s yielded AUC 1.00 with 100% sensitivity and specificity in a small analysis.

Performance noteOverall correlation between PSV and angiographic stenosis was weak (rho = 0.35); sensitivity/specificity at 124 cm/s were 74% and 65%, respectively.

MES positivity threshold — Increasing to 10 MES/hour

MES positivity threshold changeRaising the threshold for MES positivity to 10 MES per hour improves clinical usefulness in peri- and post‑operative patients.

Meta-analysis contextAnalysis included 28 studies of MES with outcomes (stroke/TIA) and subgroup analyses examining increased positivity thresholds to improve predictive value.

Post-test impactAt a median pre-test probability of 3%, a positive MES test increased post-test stroke probability to ~7.1% and a negative test reduced it to ~1.2%.

Provider Actions, Prior Authorization, and Documentation

Documentation Required

Coverage tied to CPT/Diagnosis

Coverage for listed CPT codes is tied to documentation of a medically necessary indication and an appropriate covered ICD-10 diagnosis. Submit clinical documentation that links the requested CPT/HCPCS code(s) to one of the medically necessary indications described in the policy (for example, sickle cell disease screening, suspected PFO/paradoxical embolism, evaluation of suspected intracranial stenosis/occlusion, assessment during carotid endarterectomy, detection of AVM, evaluation of suspected brain death, etc.).

Ensure an appropriate ICD-10 code from the covered list is present and clearly connected to the clinical rationale.
Covered CPT codes (when selection criteria are met): 93886, 93888, 93890, 93892, 93893.
ICD-10 examples: D57.00-D57.819 (sickle-cell disorders), Q21.10-Q21.19 (atrial septal defect/PFO), I60-I69 (cerebrovascular diseases), I77.74 (dissection of vertebral artery), P05-P07 (preterm/low birth weight), etc.

Prior Authorization

Prior authorization not specified in excerpt

The policy excerpt does not specify a formal prior authorization program or a required prior authorization code. However, prior authorization may still be appropriate in some local payer or plan implementations — check member-specific plan rules.

No explicit prior authorization requirement is stated in this policy excerpt.
Providers should verify member benefits and any site-specific prior authorization processes before scheduling.
When indications requested are those for which alternative imaging is typically preferred (e.g., cardiac TEE for precise anatomy of PFO, MRA/CTA or carotid duplex for extracranial carotid disease), payers may request justification or preauthorization.

Note

Sickle cell screening pathway

When TCD is used for sickle cell disease screening, follow guideline-based pathways: screen children with sickle cell anemia (age 2–16 years) periodically (approximately every 6 months is suggested by accepted guidance) to identify those with elevated velocities who may be offered chronic transfusion therapy to reduce stroke risk.

TDU screening identifies high-risk children (time-averaged mean velocity ≥ 200 cm/sec) who may be candidates for chronic red blood cell transfusion to reduce stroke risk.
Document screening interval, results, and the clinical plan for elevated velocities (e.g., referral for chronic transfusion program).

Note

Confirmatory testing

When TCD/TCCS findings will determine invasive management (e.g., detection of right-to-left shunt or planning for PFO closure, or suspected intracranial stenosis requiring intervention), confirmatory or complementary testing is recommended to define anatomy and guide therapy.

For right-to-left shunt: consider transesophageal echocardiography (TEE) if precise anatomic detail is required prior to PFO closure.
For intracranial stenosis/occlusion or pre-procedural planning: consider MRA or CTA (or conventional angiography) as indicated.
When using TCD for emboli detection or assessing occlusion in acute ischemic stroke, consider follow-up vascular imaging (CTA/MRA) per local stroke protocols.

Documentation Required

Timing and operator documentation

Document the timing of the examination relative to symptom onset and the qualifications of the operator/ interpreter. For acute ischemic stroke or transient ischemic attack, include timing (hours since symptom onset) and level of experience of personnel performing and interpreting the study.

Include date/time of symptom onset and date/time of TCD examination when used for acute stroke/TIA evaluation.
Record the name, title, and credentialing/qualification of the individual acquiring and interpreting the TCD (per ASNM/ASN and professional society guidance).
Document service-specific diagnostic criteria and any on-going self-validation or quality assurance activities.

Note

Administrative links and policy history

This section contains administrative links and notes regarding policy history and local implementation variability. Providers should use the most current plan-specific administrative resources and review the policy history/definitions when applying coverage rules.

Effective date: 1999-09-13; review history and next review date noted in administrative header.
Local practice variation affects choice of imaging modality (MRA, CTA, CDUS, TCD) and any administrative prior authorization processes.
Refer to plan/member-specific resources for definitions and claim submission guidance.

Denial Risk

None specified in this part of the document

No additional provider actions are specified in this portion of the document beyond documentation, indication linkage, and adherence to professional qualifications; if an indication is not listed in the medically necessary section, TDU is considered experimental/investigational and may be denied.

Requests for TDU for indications listed as experimental/investigational in the policy excerpt (e.g., epilepsy, adults with sickle cell anemia, brain tumors, head trauma, migraine, etc.) may be denied.
Ensure clinical documentation supports a listed medically necessary indication and ties to a covered ICD-10 code to avoid denial risk.

Background and Definitions

Transcranial Doppler ultrasonography (TCD/TDU) is a noninvasive ultrasound technique that measures blood flow velocities in major intracranial arteries and provides physiologic assessment of cerebral hemodynamics. It is used to evaluate collateral circulation, detect micro‑embolic signals, screen children with sickle cell disease for elevated time‑averaged mean velocities (e.g., ≥200 cm/sec) indicating high stroke risk, assess vasospasm after subarachnoid hemorrhage, and detect right‑to‑left shunts using bubble contrast studies. TCD complements anatomic imaging by offering dynamic flow information but has limitations in insonating some arterial segments and requires qualified operators for reliable acquisition and interpretation.

Time-averaged mean velocity (TAMM) — Definition and relevance

DefinitionTime‑averaged mean velocity (TAMM) is a Doppler‑derived average flow velocity metric calculated from Doppler spectra (mean velocities over the cardiac cycle).

Clinical relevanceIn children with sickle cell disease, TAMM ≥200 cm/sec is used to identify high stroke risk and guide preventive chronic transfusion therapy.

Measurement contextTAMM is derived from TDU recordings of intracranial artery velocities obtained through cranial foramina using pulsed low‑frequency Doppler transducers.

Bubble contrast TCD — Agitated saline microbubble injection to detect right-to-left shunts

DefinitionBubble contrast TCD (TCD-BS) uses injection of agitated saline microbubble contrast into a peripheral vein during maneuvers (e.g., Valsalva) to detect right‑to‑left cardiac or extracardiac shunts by identifying microbubbles in cerebral circulation.

IndicationUsed as a noninvasive screening alternative when transesophageal echocardiography (TEE) is contraindicated or unavailable for detecting patent foramen ovale or other RLS.

PerformanceLarge prospective multicenter studies using standardized protocols have shown TCD-BS to be safe and highly sensitive for identifying RLS, with high concordance versus TOE in selected cases.

Microembolic signals (MES) — Definition and clinical meaning

DefinitionMicroembolic signals (MES) are transient high‑intensity signals detected by TCD representing particulate or gaseous emboli (thrombus, plaque debris, platelet aggregates, lipid, or air) passing through intracranial arteries.

Clinical meaningPresence of MES is associated with increased risk of future stroke/TIA in patients with carotid stenosis and other embolic sources; prevalences differ by symptomatic status (e.g., 43% symptomatic vs 10% asymptomatic carotid stenosis in pooled data).

Use casesMES detection has been studied for peri‑/post‑operative monitoring (CEA, CABG), stroke risk stratification, and research settings; thresholds for positivity affect predictive value.

TCD-BS (bubble study) — Definition and sensitivity vs TEE

DefinitionTCD‑BS (transcranial Doppler bubble study) is TCD performed during injection of agitated saline microbubbles to screen noninvasively for right‑to‑left shunts such as patent foramen ovale.

Sensitivity vs TEETCD‑BS is highly sensitive and technically feasible; reported TCD sensitivity versus TEE varies by study but standardized multicenter TCD‑BS protocols demonstrated high concordance with TOE in confirmed cases.

SafetyProspective multicenter studies reported a very low rate of ischemic complications during or after TCD‑BS (0% in one 508‑patient series; 95% CI: 0 to 0.6%).

MES / HITS — Definition and study contexts

DefinitionMES / HITS are transient Doppler‑detected high‑intensity signals (microembolic signals or high intensity transient signals) representing particulate or gaseous emboli traveling in cerebral arteries.

Study contextsDetected and studied across carotid stenosis cohorts, intra‑cranial stenosis, cervical dissection, aortic plaque, and perioperative monitoring (CEA, CABG); used as a risk stratification marker in multiple prospective studies and meta‑analyses.

Prevalence examplesPooled prevalences in carotid disease: 43% in symptomatic and 10% in asymptomatic patients; presence of even 1 MES was associated with increased odds of future events in pooled analyses.

Peak systolic velocity (PSV) — Definition and use to estimate arterial stenosis

DefinitionPeak systolic velocity (PSV) is the sonographic measurement of the highest blood flow velocity during systole obtained from Doppler spectra and is used to estimate degree of arterial stenosis.

Application examplesPSV cut‑offs have been proposed for basilar artery stenosis (e.g., 124 cm/s) and for TCCS detection of in‑stent restenosis (e.g., 132 cm/s) though correlations with angiographic stenosis may be modest.

Measurement contextPSV is reported from transcranial Doppler or transcranial color‑coded sonography recordings sampled from specified arterial segments and compared to angiographic standards in validation studies.

Clinical Policy Bulletin — Definition and administrative role of the document

DefinitionClinical Policy Bulletin: an Aetna document developed to assist in administering plan benefits; provides a partial, general description of plan or program benefits and is not a contract or medical advice.

Administrative roleUsed to define medical necessity and investigational indications, list associated CPT and ICD‑10 codes, and guide coverage decisions for members and providers.

Document updatesIncludes policy history with last review date (06/05/2023), original effective date (09/13/1999), and next scheduled review (04/11/2024).

Policy Summary

PayerAetna

PolicyTranscranial Doppler Ultrasonography

Policy CodePolicy 0353

Change TypeNo material changes

Effective DateSep 13, 1999

Next Review DateApr 11, 2024

Key ActionDocument that the indication meets a listed medically necessary reason and include an appropriate ICD-10 diagnosis when submitting covered CPT codes.

SourceLink

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