Tatsuyo Ishidoya

  • Citations Per Year
Learn More
A radiophotoluminescent (RPL) glass rod dosimeter (GRD) and a small active volume p-type silicon diode detector are used for the measurement of the output factors from Gamma-Knife fields. The GRD system consists of small rod-shaped glass chip detectors and an automatic readout device. The output factors measured with the GRD from the 14, 8 and 4 mm helmets(More)
In a 15-month-old girl with patent ductus arteriosus (PDA) with pulmonary hypertension, division of the PDA was undertaken, but she died of heart failure 7 months post-operatively. Morphometric study of biopsy and autopsy lungs showed that medial hypertrophy and pulmonary intimal lesions developed markedly after surgery. Severe pulmonary hypertension and(More)
The time-resolved photoluminescence from a phosphate-glass photoluminescence dosimeter (GD-300) was compared for different quality radiations: relativistic heavy ions (12C and 40Ar) and 60Co gamma rays. The intensities of photoluminescence afterglow at 2-7 micro(s) after pulsed UV excitation, i.e., in the time range used for conventional dosimetry, soon(More)
A radiophotoluminescence dosimetry has been proposed using a spherical silver-activated phosphate glass with a diameter of 1.5 mm. A 6 MV photon dose of 2 Sv (2 Gy) was delivered to 14 spherical glass samples placed between two solid water phantoms at a depth of 10 cm. The samples were positioned within a 20 x 20 mm(2) centred at beam axis to ensure uniform(More)
An autopsy case of a hepatocellular carcinoma (HCC) with unusual metastasis to the mucosa of the small intestine is reported. The patient was a 73 year old female. At autopsy, the liver weighed 970 g, and an ovoid and necrotic 6 x 5 cm sized tumor was found in the right posterior lobe with many daughter tumors within the cirrhotic liver. The tumor embolus(More)
A radiophotoluminescent (RPL) glass rod dosimeter (GRD) and a small active volume p-type silicon diode detector are used for the measurement of the helmet output factors from five Gamma-Knife units, which include four Model B units and a Model C unit. The output factors for the five units measured with the GRD from 14, 8 and 4 mm helmets relative to the 18(More)
A simplified system for measuring time-resolved photoluminescence (PL) induced by UV laser pulses (lambda = 337 nm) is designed by a combination of a commercial PL reader and a digital oscilloscope. Using this system, PL emissions after pulsed UV excitation from a chip of sapphire (Al2O3) are successfully measured with intervals of 10 ns. It is thus(More)
Transmission of visible light and ultraviolet radiation was examined for a phosphate-glass photoluminescence dosimeter irradiated with Co source gamma rays in the dose range of 1-60 Gy (H2O). The transmission for the wavelengths (lambda) less than 600 nm decreased with increasing irradiation dose beginning at 6 Gy. An approximate 20% reduction of(More)