Diagnostic Performance of the Resistance Index (RI) for the Assessment of Cerebral Vasoreactivity in Transcranial Doppler

Inclusion Criteria:

• The patient must have given their free and informed consent and signed the consentform

• The patient must be a member or beneficiary of a health insurance plan

• Stenosis ≥ 70% in diameter reduction in NASCET equivalent or occlusion ofatheromatous origin of the cervical internal carotid artery, asymptomatic orsymptomatic.

• Presence of a temporal window sufficient to record the homolateral and contralateralmiddle cerebral artery.

• Patient of legal age with free and informed consent.

• Patient who has signed the consent form.

• Patient affiliated or beneficiary of a health insurance plan.

Exclusion Criteria:

• The subject is participating in an interventional study, or is in a period ofexclusion determined by a previous study

• The subject refuses to sign the consent

• It is impossible to give the subject informed information

• The patient is under safeguard of justice or state guardianship

• Contraindication to Acetazolamide Diamox® injection.

• Absence of temporal acoustic window (non visualization of the cerebral parenchyma,no recordable intracranial vessel).

• Insufficient temporal window (visualizable brain parenchyma, no recordable MCA)

• Internal or common carotid artery stenosis ≥70% or occlusion, contralateral to theprimary lesion.

• Stenosis ≥50% of the middle cerebral artery homolateral or contralateral to thecervical lesion.

• Patient in exclusion period determined by another study.

• Patient under court protection, guardianship, or conservatorship.

• Patient refusing to sign the consent form.

• Patient unable to express his or her will (dementia, disturbed consciousness, etc.)

• Patient for whom it is impossible to give informed information for health reasons orbecause of a language barrier.

• Pregnant, parturient, or breastfeeding patient.