A collimator simulator which is an accessory in radiology equipment, has been made. This was created as a learning medium to complete students' understanding studying x-rays part of electromagnetic waves. The research divided into two stages, namely the manufacture simulators and implementation teaching materials. equipped with blades that are used limit radiation field area. In this study, lam...

The aim of this study was to develop a phantom and analysis software that could be used to quickly and accurately determine the location of radiation isocenter to an accuracy of less than 1 mm using the EPID (Electronic Portal Imaging Device). The proposed solution uses a collimator setting of 10 × 10 cm2 to acquire EPID images of a new phantom constructed from LEGO blocks. Images from a number...

The problems caused by miniaturization of the goniometer are discussed from the viewpoint of the stress error caused by mis-setting of the specimen and misalignment of the collimator and detector for the Q assembly X-ray stress analyzer using a position sensitive detector. The stress errors were calculated using a model and a simulation method. It was found that they tend to increase with the d...

PURPOSE To develop a real-time target position estimation method using stereoscopic kilovoltage (kV)/megavoltage (MV) imaging and external respiratory monitoring, and to investigate the performance of a dynamic multileaf collimator tracking system using this method. METHODS AND MATERIALS The real-time three-dimensional internal target position estimation was established by creating a time-var...

The dose distributional properties of a p(50) Be neutron beam using a continuously variable multi-leaf collimator are presented and compared with a 6 MV photon beam. The differences in physical dose delivery between these two radiation modalities are generally insignificant for radiation therapy, and stringent comparisons of neutron and photon treatments should therefore be possible. The flexib...

In the present paper, we propose a method to fabricate a ‘‘micro-collimator’’ with a thickness of 15mm. A commercially available PADC film with a thickness of 100mm was first chemically etched with NaOH/ethanol solution to obtain a thin PADC film. This thin PADC film was then irradiated by 5MeV a particles through a ‘‘macro-collimator’’ with a thickness of 5mm and a hole diameter of 1mm. This P...

In single photon emission computed tomography (SPECT), a varying-focal-length cone-beam collimator can be used to reduce the truncation problem and to maintain sensitivity when imaging the organ of interest. The collimator is constructed so that the collimator holes focus to a circular symmetric, spatially varying, focal point function. The focal length increases radially from the shortest foca...

The performance of future linear colliders are limited by the effect of short-range collimator wakefields on the beam. The beam quality is sensitive to the positioning of collimators at the end of the linac. The determination of collimator wakefields has been difficult, largely because of the scarcity of measurement data, and of the limitation of applicability of analytical results to realistic...

The use of a multileaf collimator in the dynamic mode to perform intensity modulated radiotherapy became a reality at our institution in 1995. Unlike treatment with static fields using a multileaf collimator, there are significant dosimetric issues which must be assessed before dynamic therapy can be implemented. We have performed a series of calculations and measurements to quantify head scatt...

PURPOSE AND METHODS The noninvasive microsphere (NIMS) method quantifies cerebral blood flow with N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) without blood sampling of a patient, but when a fan beam collimator is used for collecting raw data in single photon emission computed tomography (SPECT), the procedure is complicated because we have to change the collimator. In phantom and clinical s...