OBJECTIVE Clip artifacts limit the visualization of intracranial structures in CT scans from patients after aneurysmal clipping with cobalt alloy clips. This study is to analyze the parameters influencing the degree of clip artifacts. METHODS Postoperative CT scans of 60 patients with straight cobalt alloy-clipped aneurysms were analyzed for the maximal diameter of white artifacts and the ang...

PURPOSE This study investigates potential gains of an improved beam angle arrangement compared to a conventional fixed gantry setup in intensity modulated proton therapy (IMPT) treatment for localized prostate cancer patients based on a proof of principle study. MATERIALS AND METHODS Three patients with localized prostate cancer retrospectively selected from our institution were studied. For ...

In this investigation, the multi-objective selection and optimization of a gantry machine tool is achieved by analytic hierarchy process, multi-objective genetic algorithm, and Pareto-Edgeworth-Grierson–multi-criteria decision-making method. The objectives include maximum static deformation, the first four natural frequencies, mass, and fabrication cost of the gantry. Further structural optimiz...

This article presents the design system for high efficiency gantry crane system using elevator and conveyor system. The basic concept for the proposed gantry crane system can be used with modification of the classical gantry crane instead of changing lots of them. However, the proposed crane system can reduce the cycle time more than the classical gantry crane. The high efficiency gantry crane ...

The computed tomographic (CT) appearance of the jugular foramen was examined in detail, and anatomic and CT sections were correlated. The pars nervosa and pars vascularis were identified, and, with intravenous contrast enhancement, a rapid sequence of scans at a gantry angle of +30 degrees to the canthomeatal line demonstrated cranial nerves IX, X, and XI. The osseous margins of the jugular for...

This paper describes solutions that can be applied to pneumatic manipulator problems in positioning, both for angle trajectories and for long linear trajectories, used in construction tasks. Optimal positioning of a pneumatic manipulator along angle trajectories with minimum control energy consumption is given. The implementation of the control system is presented. Control algorithms for a long...

Recently, the MRI-linac prototype at UMC Utrecht was upgraded with a ring-based gantry, where all linac components are mounted on a ring around the MR scanner. Although adaptations have been made to both linac and MR magnets in order to account for mutual magnetic interference, interference problems cannot be ruled out completely. Therefore, in this paper the impact of gantry position dependent...

AIM In this study, the dosimetric properties of the electronic portal imaging device were examined and the quality assurance testing of Volumetric Modulated Arc Therapy was performed. BACKGROUND RapidArc involves the variable dose rate, leaf speed and the gantry rotation. The imager was studied for the effects like dose, dose rate, field size, leaf speed and sag during gantry rotation. MATE...

By comparing predicted dose images with physically acquired images, radiotherapy fields may be verified. A good portal dose verification chain should be accurate and unrestricted in terms of gantry angle and patient-imager air gap distance. We present latest enhancements and rigorous tests of a portal dose prediction framework based on Monte Carlo (MC) radiation transport. We also present initi...