Carotid Plaque Imaging in Acute Stroke
Carotid Plaque Imaging in Acute Stroke
The purpose of this study is to determine the frequency, characteristics, and consequences of
 vulnerable carotid artery plaques ipsilateral to an acute ischemic stroke or TIA in the
 territory of the internal carotid artery.
Even with extensive diagnostic workup the underlying etiology remains unidentified in about
 25% of patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA).
 Non-invasive high-resolution magnetic resonance imaging (HR-MRI) of the carotid artery allows
 detecting vulnerable plaques (VP) and quantifying single plaque components. The hypotheses
 behind this study are that i) a substantial proportion of cases of AIS and TIA within the
 anterior circulation and no identified cause (cryptogenic AIS or TIA) are caused by VP in the
 carotid artery; ii) that these patients are at a high risk of developing a recurrent stroke,
 TIA, or clinically silent lesions detectable by brain MRI; and iii) that VP in the carotid
 artery are associated with specific infarct patterns as detected by diffusion-weighted MR
 imaging. Finally, the investigators will search for biomarkers associated with vulnerable
 carotid artery plaques. Motivating this study are the following considerations: i) data on
 the frequency and characteristics of VP in patients with cryptogenic AIS or TIA will provide
 valuable insights into stroke mechanisms; ii) depending on the results this study may have
 implications for diagnostic decision making and provide the basis for the planning of
 targeted interventional studies.
Inclusion Criteria:

 -  Age > 49 years old

 -  Acute ischemic stroke or transient ischemic attack (TIA)

 -  Neurological symptoms compatible with a stroke or TIA in the anterior circulation
 (territory of the internal carotid artery)

 -  Onset of symptoms within the last 7 days

 -  1 or more acute ischemic lesion(s) visible on MR diffusion-weighted imaging (DWI) in
 the territory of a single internal carotid artery

 -  Presence of carotid artery plaques in the ipsilateral or contralateral carotid artery
 as defined by ultrasound (criteria: plaque thickness at least 2mm; located within 1cm
 proximal or distal to the carotid bifurcation)

 -  Written informed consent

 Exclusion Criteria:

 -  Primary referral to an outside hospital (to avoid recruitment bias)

 -  DWI positive lesions outside the territory of a single internal carotid artery

 -  Carotid artery stenosis > 69% (North American Symptomatic Carotid Endarterectomy Trial
 (NASCET) criteria) ipsilateral to the stroke or TIA as defined by ultrasound (systolic
 peak flow velocity ≥ 300 cm/s)

 -  Standard contra-indications for MRI

 -  Documented allergy to MRI contrast media

 -  History of radiation to the neck area

 -  Renal clearance < 30 ml/minute

 -  Creatinine levels > 2 times the upper limit of the standard range of the respective
 laboratory within the last 30 days prior to MRI

 -  Surgical procedure within 24 hours preceding the MRI