Images are derived from flow physiology, not direct luminal imaging. Artifacts peculiar to specific machines and acquisition techniques must be considered in interpretation. M.R.A. is particularly useful for non-invasive imaging of the major venous sinuses. The sensitivity and specificity of the new technique compared to arteriography and M.R.A. have not been fully defined. The major modifiable risk factors for cerebrovascular atherosclerosis are shown here.
Smoking is especially related to cervical carotid atherosclerosis.
Patients with several risk factors multiply their stroke, so that smokers with hypertension have a 10 to 20 times increased risk. Thus, risk factor reduction is especially critical in the presence of multiple risk factors.