5 cm of antero-posterior diameter), usually involving the distal tract of the common carotid artery and extending through the bulb to the internal carotid artery origin, can be easily recognized. Moreover, the 3D reconstruction, rotating in the different planes, EX 527 mw allows a better global identification of the anatomy (Fig. 2). However, the reconstruction images have always to be considered with caution for final diagnostic decisions, as flow disturbances can cause several artifacts in the post-processing image reconstruction:

final 3D pictures cannot be considered alone and without the previous or concomitant mandatory analysis of the bidimensional images. Extracranial vessels course abnormalities are frequent and generally asymptomatic in the general population [15]. According to their angle in respect to the vessel, they can be classified in “tortuosities” and “kinkings”, when changes in the vessel course are greater than 90°. Even though these alterations are asymptomatic and without clinical relevance in the normal subject, tortuosities and kinkings have to be identified prior to surgical procedures, since they may hinder – for example – the intravascular positioning of a stent, while the anatomical approach and clamping of the internal carotid artery may be easier during endarterectomy [16]. Bidimensional standard US imaging with Duplex, Color and Power Doppler easily reveal

the changes of the blood flow direction according to the vessel direction change. While in the bidimensional images it is usually necessary to repeatedly correct the color box insonation Tacrolimus chemical structure angle or to adjust the probe orientation to obtaining optimal complete vessel recognition, the

3D reconstruction can be of help to gain the whole visualization “at a glance” [to view the figure, please visit the online supplementary file]. 3D imaging of carotid stenosis have been performed with different techniques: (1) by the 3D reconstruction of the internal carotid artery plaque structure from either the US B-Mode and/or from the vessel wall parenchymal (CT/MRI) imaging; (2) by the 3D reconstruction of the inner residual lumen, visualized Acetophenone with the Power Doppler or with other imaging techniques. These two methods may have their own disadvantages, fundamentally represented by the possibility of under interpretation of the stenosis in case 2, because the vessel considered as normal reference is – actually – only supposed-to-be-so, not being the vessel wall directly visualized. In Fig. 3 (Clip 3), the 3D reconstruction of a cases of internal carotid artery stenosis is presented. Note as the visualization of the “missing part” of the vessel lumen in 3D US, reconstructed on the basis of the residual flow. Increased blood flow velocities may induce an underestimation of the stenosis in the 3D ultrasound reconstruction, because the image is computed on the base of the flow signal – increased in this case – from the inward flow.