Group A - patients (age >40 years), that had a CT scan (chest/abdomen) for any indication, will be evaluated for aortic calcifications. The patients will be additionally examined for carotid artery stenosis by Doppler ultrasound. (100 patients) Group B - Patients that were diagnosed by Doppler ultrasound, and were found to have a severe carotid artery stenosis. These patients are scheduled for a computed tomography-angiography (regardless for the research) of the cervical arteries, will be additionally complete abdominal/chest tomography scan, without additional contrast. (50 patients).