[18F]AlF-NOTA-octreotide PET/MRI in Carotid Artery Disease

Inclusion Criteria: 1. Participant is aged over 18 years. 2. Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedure 3. CT angiography imaging at baseline should be available as part of routine care 4. Participant is diagnosed with a recent ischemic stroke or high-risk TIA (ABCD2 ≥ 4) in the carotid artery territory and ≥ 30% carotid artery stenosis. The stroke/TIA has occurred no more than 21 days prior to tracer administration. Exclusion Criteria: 1. Female who is pregnant or breast-feeding 2. Participants with a cardio-embolic stroke, small vessel stroke or other defined stroke etiology according to the TOAST classification (23) 3. Participant has a previous or ongoing recurrent or chronic disease at high risk to interfere with the performance or evaluation of the trial, according to the judgment of the investigator 4. Participants treated with carotid endarterectomy or carotid artery stenting within the past year 5. Subject has a contra-indication for or cannot tolerate MR scanning 6. Subject has an impaired renal function estimated glomerular filtration rate (eGFR) \< 40 ml/min/1.73m² (the last known value may not date from more than 3 months prior to the study PET/MR; if not available a blood analysis may be performed as part of the trial) 7. Concurrent treatment with corticosteroids and/or somatostatin analogues 8. Subject is unwilling or unable to perform all of the study procedures, or is considered unsuitable in any way by the principal investigator