The Use of Anti-CD4 mAb-Fragment for Imaging of Local Inflammation in Patients With Carotid Artery Stenosis

Inclusion Criteria: * male and female with either symptomatic (\> 60%) or asymptomatic (\> 80%) carotid artery stenosis between 50 and 80 years of age * Symptomatic stenosis of the A. carotis interna is defined as occurence of focal ischemic symptoms in the area of the supplying vessel, occurence of a transischemic attack (TIA), occurence of focal neurologic dysfunction or unilateral blindness. * informed consent in accordance with ICH GCP and § 40 AMG and StrahlSchV * sonography status from the patient is present (printout is available) * patients available for carotid surgery within 3 months after diagnosis of carotid artery stenosis * In patients with bilateral disease, only the stenosis considered for surgery will be included in the endpoint evaluation. Exclusion Criteria: * patients \> 80 years * major disease of the cardiovascular system, respiratory system, hepatobiliary system or CNS, which prevents patients from the study participation as to the opinion of the investigator * hepatic (transaminases \> 3 x norm) or renal (serum creatinine increase \> 2x norm) insufficiency * regular drug intake of biologics. Intake of all other drugs must be judged by investigator and must be the strictly documented * previous administration of xenogenous proteins * history of anaphylactic reaction to any drug administered by a parenteral pathway * previous participation in a radiopharmaceutical drug trial (unless the effective dose acquired by participation in the current trial will remain below 10 mSv) * participation in any clinical drug trial within 3 months prior to enrolment * women of child-bearing potential (child-bearing potential to be ruled out by one of the following: at least 2 years past menopause, hysterectomy, bilateral oophorectomy, bilateral tubal ligation) * Patients presenting clinical signs of severe systemic infection (CRP \> 50 mg/dl) * Carotid Surgery (TEA) not possible within a time frame of 7 days after imaging * Patients with bilateral carotid stenosis if clinically regarded as critical by the angiologists.