Digital Subtraction Angiography (DSA) has long been considered the standard for evaluation of carotid stenosis but has well-known risks and limitations. DSA allows only a limited number of views, which can lead to an underestimation of the degree of stenosis by as much as 40%. DSA is also a relatively expensive technique that uses numerous resources. Finally and perhaps most importantly, there is a small but definite risk for major complications secondary to the procedure itself, the Asymptomatic Carotid Atherosclerosis Study Committee reported a 1.2% risk of persisting neurologic deficit or death following DSA.(Bruno et al., 2001).Carotid ultrasound has been used worldwide as a noninvasive diagnostic test for evaluating extra-cranial carotid artery diseases. Besides its noninvasiveness, ultrasound is cost-effective and easy to perform.(Gernot et al., 2002).Power Doppler imaging is a commercially available variant of color Doppler flow imaging instrumentation. With the aid of power Doppler imaging, the strength of the Doppler signal is displayed in color, so the image of the carotid artery produced by power Doppler imaging is more suitable for tortuous carotid vessels; Therefore the Doppler studies could be performed rapidly and efficiently.(Edward et al., 2000).Recent studies of 3D Doppler sonography show that 3D power Doppler sonography is an accurate method in screening atherosclerotic lesions of the carotid artery and additionally provides excellent 3D volumetric surveying that may be helpful in planning of surgery.(Keberle et al., 2003).Computed tomography angiography (CTA) is a noninvasive method of assessing the vascular system; which is evolving rapidly. The development and widespread availability of helical CT and advanced post-processing techniques has made CTA a practical alternative to angiographic studies. The rapid acquisition speed of helical CT allows a large volume to be imaged during the narrow temporal window of first pass peak vascular opacification during a single breath hold.(Peter et al., 2000). 3D reconstruction techniques have been developed recently employing CT angiography in addition to ultrasonography to overcome the limitation of the 2D of these modalities. 3D reconstruction techniques has volumetric potentialities which has important implications in assessing stenotic lesions. It demonstrates some encouraging findings in carotid artery imaging.(Schminke et al., 2003).