Conventional angiography is considered to be gold standard for evaluating the degree of carotid artery stenosis. However, this technique carries a risk of complications. Thus, noninvasive techniques have been developed to avoid conventional angiography. Among these techniques, duplex sonography certainly constitutes the most attractive method, providing both morphological and hemodynamic data by combining different acquisition modalities. Contrast-enhanced MR angiography (MRA) is a recent development providing information on the intracranial and cervical vascularization in a short acquisition time. Previous studies have showed the reliability of this technique to detect severe carotid stenosis. Helicoidal CT is a third noninvasive method providing a reliable evaluation of carotid artery stenosis by analyzing both the axial CT images and the 3D reconstruction. However, CT angiography requires a radiation does and injection of an iodinated contrast agent. Moreover, the surrounding venous and bone structures may obscure evaluation of the arterial lumen.