Objective To reduce the artifacts produced by cardiac or respiratory motion,through the application of exact reconstruction algorithm with triple-source CT in dynamic reconstruction.Methods Simulation studies on two dynamic phantoms were performed with exact reconstruction algorithms of both single-source and triple-source spiral CT.The performance of triple-source spiral CT in dynamic reconstruction was evaluated with comparing the reconstruction results from triple-source and single-source configurations.Results The triple-source configuration could effectively reduce the artifact in dynamic reconstruction.Conclusion The results of this paper confirm the validity of the exact reconstruction algorithm of multi-source CT,which has the potential to improve the image quality in cardiac imaging and small animal imaging.

Computed Tomography(CT) is one of the successful methods, in which mathematical theories are combined with engineering technology. Volume CT will replace the cross-sectional CT that has been widely used. In this paper two new cone vertex orbits, which are circle-and-arc and regular triangular pyramid lines, have been proposed and their complete conditions for exact reconstruction have been obtained. After having studied circle-and-n-line cone vertex orbit which is one of the important orbits in volume CT, we have given a better proof about the complete condition in circle-and-line and circle-and-2-line cone vertex orbit and have obtained some proper conclusions. Finally, we extend the above results to circle-and-n-line vertex orbit. These results will be useful for the design of direct volume imaging.
Algorithms ; Artifacts ; Computer Simulation ; Tomography, X-Ray Computed ; methods

BACKGROUND:Based on the integration of virtual reality technology with acupoints, acupuncture can be expressed three-dimensional y.
OBJECTIVE:To explore the structure of points through reconstructing digitalized three-dimensional visualization of Neiguan (PC6) structure based on VOXEL-MAN and Micro-XCT.
METHODS:Muscles and other tissues adjacent with Neiguan (PC6) were segmented and merged based on the VOXEL-MAN system combined with the anatomical knowledge of acupoints;nerves and blood vessels were performed with three-dimensional reconstruction;the needle-inserting animation of Neiguan (PC6) was obtained by running script file. Three-dimensional visualization and virtual needle-inserting researches of Neiguan (PC6) were performed. Nature of the acupoints was detected by the Micro-XCT-200 machine additional y.
RESULTS AND CONCLUSION:The visualization of the anatomical structure of local Neiguan (PC6) was completed, and the localization and expression of Neiguan (PC6) in the digitized virtual human were realized. The Neiguan (PC6) structure was researched with Micro-XCT-200, and showed there was no new tissue. Local three-dimensional reconstruction of the acupoint structure could help to display the anatomical structure of acupoints and simulate the acupuncture process. It could also help to observe the relationship between the needle body and the surrounding tissues during needle-inserting, which supplying a good basis not only for exploring the security of needle-inserting, but also for improving the clinical effect of acupuncture. The research on the structure of acupoint Neiguan (PC6) by Micro-XCT-200 provides further experimental evidence for the hypothesis of three-dimensional acupoint.

An effective MR and PET image registration method designed for clinical use is given in this paper. A new correlation ratio similarity measure for voxel intensity based medical image registration was adopted. Detailed discussion on methods of rigid transformation, resampling, multi-resolution medical image representation and optimization for accelerated multi-resolution registration scheme is also given in this paper. At last, experimental results based on clinical MR and PET medical images show that correlation ratio based multi-resolution registration method works well and is faster than most existing direct voxel intensity based registration methods under clinical scenario.
Algorithms ; Humans ; Image Processing, Computer-Assisted ; methods ; Magnetic Resonance Imaging ; Models, Statistical ; Tomography, Emission-Computed, Single-Photon

Computed tomography angiography (CTA) is a useful approach for diagnosing vascular diseases. In this paper, we proposed a reconstruction algorithm for dual-source spiral CT with variable pitch. The projection data are collected by the double-source double-multislice spiral CT (DSDMS-CT). However, the pitch of the DSDMS-CT is variable other than being constant. We have developed a new formula performing interpolation along Z-axis for dual-source spiral CT with variable pitch. The dual-source spiral CT with variable pitch can chase contrast bolus more flexibly and more effectively. The simulation results show the correctness and efficiency of the proposed algorithm.
Algorithms ; Coronary Angiography ; methods ; Humans ; Tomography, Spiral Computed ; instrumentation ; methods