Influence of Orbital Implant Length and Diameter on Stress Distribution: A Finite Element Analysis.

Purpose: A mathematical simulation of stress distribution around orbital implants was used to determine which length and diameter of implants would be best to dissipate stress.

Methods: An integrated system for computed tomography data was utilized to create a 3-dimensional model of craniofacial structures. The model simulated implants placed in the 7, 11, and 12 o'clock positions of the orbital rim.

[Cone-beam pseudo lambda tomography under FDK framework].

The medical CT scanner is rapidly evolving from the fan-beam mode to the cone-beam geometry mode. In this paper, a new cone-beam pseudo Lambda tomography was proposed based on the Noo's fan beam super-short scan formula and FDK framework. The proposed pseudo-LT algorithm, which avoids the computation of any PI line and any differential operation, has a significant practical implementation, thus leading to the images with quality improvement and reduced artifacts.

[Elimination of direct derivative of the projection data for image reconstruction based on hybrid filter in helical cone-beam CT].

Objective: We present an alternative approach for precise reconstruction of the images from helical cone-beam projections combining Hilbert filter and Ramp filter.

Methods: Based on the Katsevich algorithm framework, the proposed algorithm combined the FDK-type algorithms and Katsevich algorithm for their respective advantages, to completely avoid the direct derivatives with respect to the coordinates on the detector plane.

Results: The experimental results validated the accuracy of the new algorithm, and this approach significantly improved the resolution of the reconstructed images with much reduced artifacts.