The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
To determine the accurate radiation dose for a specific small volume of tissue, confirmation of the temporal location of a target position is very important. The temporal location of the target can help improve the accuracy of target localization. A kilovoltage cone-beam computed tomography (CBCT) system mounted on a linear accelerator can verify the target on each treatment day, but this system requires...
The purpose of our research is to develop a fast image reconstruction algorithm with a ray-driven method using a general-purpose computing on graphics processing units (GPGPU). The ray-driven method based on a projection bin uses sample points that are located on the center of the bin. In the implementation with a ray-driven method using a GPU, a collision of memory accesses sometimes reduces the...
The purpose of our research is to develop a new pinhole SPECT system using a triple head gamma camera system. The proposed data acquisition geometry used multi-pinhole collimators attached to each gamma camera. Acquired data were reconstructed with the OS-EM method. We evaluated the feasibility of the system with simulations. In the simulations, we evaluated three types of the pinhole collimators...
To accomplish accurate irradiation to a target, image information about the target is very useful in radiotherapy. A kilo-voltage cone-beam computed tomography (kV-CBCT) system mounted on a linear accelerator can verify the accuracy of the set-up position and the size and location of the target on each treatment day. However, the gantry of the CBCT system is heavy and so requires a long data acquisition...
The purpose of this study is to remove the cervical vertebrae from a dental panoramic x-ray image with a tomosynthesis method. The elimination of the cervical vertebrae is based on the concept of the tomosynthesis method. We first measured the shift-amount that was required to reconstruct a panoramic x-ray image of the dental arch with a calibration phantom. Then, we made the shift-amount that was...
The development of a pixilated semiconductor detector such as CdTe or CdZnTe, which is available for x-ray imaging, has been pursued by many researchers. In the case of x-ray imaging, the photon flux is very high, and thus conventional CT systems adopt energy integration detectors. On the other hand, the reduction of patient dose becomes one of the major issues in state-of-art CT systems. Thus, detectors...
The purpose of our research is to develop a new brain single photon emission CT (SPECT) system with a semiconductor detector. For the detector we adopted CdZnTe semiconductor modular detectors to improve the energy resolution and spatial resolution. The size of a module was 39 × 39 mm2 (16 × 16 pixels) and the thickness of the CdZnTe crystal was 5 mm. With this modular detector we made three detector...
The purpose of our research is to measure the amount of contrast agents used in x-ray CT accurately. The use of contrast agents such as gold nano-particles enables molecular imaging with the x-ray CT system. To realize an energy discriminating measurement, we have developed a photon counting detector with a CdTe semiconductor that is able to measure x-rays with the count rate of 107 cps/mm2 with four...
We have developed an electron-tracking Compton camera (ETCC) for new medical imaging device. Conventional gamma camera, PET and SPECT, have the problem of energy limitation. This problem is one of the major problems for this study. However, our ETCC has a wide energy dynamic range (200–1300 keV). Also ETCC have the wide field of view because ETCC does not need a collimator and does not need to catch...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.