The virtual 3D image presentation may be useful also for surgeons, to better study anatomical boundaries of the structures to be submitted to surgical procedures [6] and [7]. For carotid arteries, it has been applied to study carotid plaque morphology, surface and volume during atherosclerosis progression [8], [9], [10], [11], [12] and [13]. Recently we have published the possibility of 3D US bifurcation imaging in other conditions than carotid stenosis Gamma-secretase inhibitor [14], easily visualizing bifurcation anatomy changes of the caliber and vessels course modifications. Patients admitted to our US laboratory for vascular screening were submitted to standard carotid duplex and to 3D US reconstruction of

the carotid bifurcation. Forty normal

subjects, 7 patients with caliber alterations (4 carotid bulb ectasia and 3 internal carotid lumen narrowing), 45 patients with course variations (tortuosities and kinkings) and 35 patients with ICA stenosis of various degrees have been investigated. The Siemens S2000 US system with high frequency linear probes (9, 14 and 18 MHz) and proprietary 3D/4D reconstruction software (v 1.6) have been used. 3D volume scans were recorded manually. After fixing the proximal tract of the common carotid artery (CC) in the center of the display in the transversal plane, a test axial scanning was performed, from proximal CC to distal internal carotid artery (ICA) – at approximately 1 cm per second speed – to adjust the visualization. The 3D ultrasound software was then switched on to record the volume scan: the Power ABT-263 in vivo box was set to the orthogonal 90° angle position;

Pulse Repetition Frequency (PRF), color gain and color persistence were adjusted during a second test axial scan, in order to reduce artifacts due to the inward flow color signal overlapping the vessel wall and to minimize color “flashing” due to the blood pulsatility. The features of the software “axial reconstruction” and “medium resolution” – that is set for a length of 10 cm to be scanned in 12 s – were selected. Data acquisition was then started and over stopped manually; a bar control displayed on the screen the feedback for maintaining a constant straight direction and scan velocity. At the end of the scan, the 3D ultrasound “volume rendering” reconstruction of the acquired volume set was started on the system. After the global 3D image presentation, B-Mode imaging was excluded and Color Magnification (Color Priority) adjusted to optimize the final visualization of the vessels. Threedimensional US reconstruction in normal subjects allows a good visualization of the carotid bifurcation. In Fig. 1 (Clip 1), an example is reported: all the extracranial carotid arteries are easily identifiable (CC: common carotid artery; IC: internal carotid artery; EC: external carotid artery; green arrow: superior thyroidal artery), with the possibility of rotating the image through different planes.