This is a biomedical, single-center, and prospective study of a consecutive patients cohort in acute ischemic stroke with carotid plaque.

The main objective of this study is to evaluate the prevalence of the contrast taking carotid plaques in these acute ischemic strokes.

The secondary objectives are:

• to determine the clinical, sonographic, CT scanner and MRI characteristics of patients in constituted acute cerebral ischemia with carotid atherosclerotic plaque taking contrast to the doppler ultrasound.
• to explore of the plaque contrast enhancement at 6 months (new injection).

Inclusion Criteria:

• All patients aged at least 18 years hospitalized with ischemic stroke signs in the carotid territory, objectified on brain MRI with positive DWI.
• Carotid plaque > 2.5 mm thickness in the ipsilateral carotid territory to the AIC, low echogenicity (Type 1, 2, 3, and 4a of the classification Geroulakos) measured by the assessment "GSM" (median gray level).
• Free and informed consent patient or his representative for contrast injection microbubble.
• Affiliated to health insurance.

Exclusion Criteria:

• Severe cerebral infarction with NIHSS> 25
• No-indications to the contrast medium injection
• Recent myocardial infarction, unstable angina.
• Heart failure stage III / IV New York Heart Association.
• Cardiac shunt left-right, respiratory distress.
• Allergy to albumin or contrast agents.
• Carotid plaques and hyperechoic calcified (however these plaques will be counted to determine their prevalence in acute AIC).
• Carotid dissection