Registration between 2D and 3D Ultrasound Images to Track Liver Blood Vessel Movement.

Background: For the accurate positioning of surgical tools, conventional intraoperative navigation systems have been developed to recognize the relationship between target positions and the tools. However, since an internal organ is deformed during the operation, registration between realtime two-dimensional (2D) ultrasound images and three-dimensional (3D) CT or MRI images is not always effective. Therefore, this study developed image registration between 2D and 3D ultrasound images considering deformation for tracking target vessel movement in the liver.

Grain boundary sliding in pure and segregated bicrystals: a molecular dynamics and first principles study.

Sliding behaviors of Σ9(221) grain boundary bicrystals have been investigated in pure metals (Al, Ag, Au, Cu, Pt and Co) and in segregated metals (Cu segregated by Al, Ag, Au, Pt and Co) by molecular dynamics simulations and first-principles calculations. The grain boundary energy, the atomic size and the electronegativity of the segregated elements were not critical for the occurrence of grain boundary sliding. On the other hand, the sliding rate increased as the minimum charge density decreased at the bond critical point.