A5062266373- Radiation Dose and Imaging
- Advanced Radiotherapy Techniques
- Digital Radiography and Breast Imaging
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Radiation Therapy and Dosimetry
- Radiation Detection and Scintillator Technologies
- Radiation Effects and Dosimetry
- Advanced MRI Techniques and Applications
- Optical Systems and Laser Technology
- Radiology practices and education
- AI in cancer detection
- Infrared Target Detection Methodologies
- Photoacoustic and Ultrasonic Imaging
- Acute Ischemic Stroke Management
- Color Science and Applications
- Radiomics and Machine Learning in Medical Imaging
- Image Enhancement Techniques
- Magnetic Properties and Applications
- Advanced Semiconductor Detectors and Materials
- Image and Video Quality Assessment
- Welding Techniques and Residual Stresses
- Atomic and Subatomic Physics Research
- Luminescence Properties of Advanced Materials
- Cerebral Venous Sinus Thrombosis
Junshin Gakuen University
2012-2025
Nagasaki Medical Center
2006
National Kyushu Medical Center
2001-2005
Clinical Research Institute
2005
Osaka University
2002
Abstract The GAFCHROMIC LD‐V1 radiochromic film is widely used in dosimetry because it can provide high‐resolution two‐dimensional dose distributions without processing. This study aimed to evaluate the response characteristics at different effective energies, from low‐energy range of mammography high‐energy computed tomography. Net pixel value (NPV)‐absorbed calibration curves for were generated using x‐rays with energies 18, 30, 50, and 80 keV reflect those diagnostic radiographic...
Abstract In recent years, radiochromic films have begun to be used for dosimetry in mammography; however, the most sensitive GAFCHROMIC XR-QA2 (XR-QA2) film is no longer available owing its discontinuation. this study, we evaluated sensitivity characteristics of LD-V1 (LD-V1) as an alternative field mammography, at a low dose and energy. Our results show that average ratio concentration change divided by each absorbed was 53.7%, indicating approximately half XR-QA2. addition, linearity...
The physical characteristics of a direct amorphous Selenium (a-Se) digital fluoroscopy and radiography system were investigated. Pre-sampled modulation transfer functions (MTF) measured using slit method. Noise power spectra determined for different input exposures by fast Fourier transform uniformly exposed samples. MTFs systems showed significantly higher values than those indirect screen-film systems. noise levels compared with under roughly the same exposure conditions. Contrast-detail...
The effects of lead equivalent and lens area radiation-protective eyewear on exposure control were examined. simulated patient underwent 10-min X-ray fluoroscopy, the dose surgeon wearing radiation protection glasses was measured using dosemeters attached to corner eye eyeball. In total, 10 types selected for measurement. Correlation analysis in with equivalence performed. negatively correlated lens. eyeball showed a strong negative correlation equivalence. Lens worn at may overestimate eye....
Abstract The effective energy calculated using the half-value layer (HVL) is an important parameter for quality assurance (QA) and control (QC). However constant monitoring has not been performed because measurements ionization chamber (IC) are time-consuming complicated. To solve these problems, a method radiochromic film (GAFCHROMIC EBT2 dosimetry (GAF-EBT2) with slight dependency errors), mobile scanner step-shaped aluminum (SSAl) filter developed. results of were compared those...
Abstract In this paper, we propose a novel radiochromic film (RCF)-based computed tomography (CT) dosimetry method, which is different from the method based on CT dose index. RCF using Gafchromic QA2 films was performed two lengths of film-folding phantoms. The phantom exposed to X-ray through single scan, while sandwiched between We analysed profile curve in directions investigate distribution. observed difference distribution as size changed. Our results contradict with previous studies...
This study developed a phantom with shape similar to that of the breast and use GAFCHROMIC films can be placed inside measure detailed dose distribution in mammography. EBT3 was on block cube irradiated mammography device absorbed horizontal depth directions. The plane highest centre chest wall side, it decreased fan shape. Along phantom, doses across entire cross-section were 16.15 mGy at surface 7.51, 3.25 1.68 depths 10, 20 30 mm, respectively. Compared mean glandular dose, proposed...
In a computed radiography (CR) system, there are number of different mechanisms that cause blurring. The aim this study was to analyze intrinsic system factors CR systems could affect the modulation transfer function (MTF), such as afterglow during readout and anti-alias filter before analog digital converter. Methods Materials: Mathematical slit edge images were generated from analytical functions. These arranged perpendicularly laser scan plate directions, respectively. influence simulated...
In mammography units, the X-ray tube focal spot is located directly above chest wall edge of detector. Therefore, beam incident at a different angle along cathode-anode axis. When on imaging plate (IP) relatively large angle, resolution property new with dual-sided reading system would be degraded compared conventional because parallax effect, which produces shift in image two sides plate. To evaluate oblique incidence effect degradation properties and detection simulated microcalcifications...
Radiochromic film dosimeters have a disadvantage in comparison with an ionization chamber that the dosimetry process is time-consuming for creating density-absorbed dose calibration curve. The purpose of this study was development simplified method curve from radiochromic within short time. This performed using Gafchromic EBT3 low energy dependence and step-shaped Al filter. compared standard method. curves created methods exhibited approximately similar straight lines, gradients were...
Mammography is one of the most effective diagnostic methods for early detection breast cancer; however, it poses risk radiation exposure. To date, mammography dosimetry has been performed according to mean glandular dose; actual exposure in not assessed. Here, we have measured dose distributions and depth doses using both radiochromic films mammographic phantoms, a three-dimensional intra-mammary assessment was conducted. The absorbed distribution at surface markedly higher on chest wall...
Purpose: The modulation transfer function (MTF) in Computed Radiography (CR) for the laser scan direction is generally lower than that plate direction. In a CR system, there are number of different mechanisms cause blurring. We analyzed intrinsic system factors could affect MTF, such as afterglow, during readout and anti-alias filter analog to digital converter (ADC) directions. Methods Materials: Mathematical slit edge images were generated from analytical functions. These arranged...