Eiichi Sato, Etsuro Tanaka, Hidezo Mori, Hiroki Kawakami, Toshiaki Kawai, Takashi Inoue, Akira Ogawa, Mitsuru Izumisawa, Kiyomi Takahashi, Shigehiro Sato, Kazuyoshi Takayama, and Jun Onagawa
A microfocus x-ray tube is useful to perform magnification digital radiography, including phase-contrast effects. The 100‐μm-focus x-ray generator consists of a main controller for regulating the tube voltage and current, and a tube unit with a high-voltage circuit and a fixed anode x-ray tube. The maximum tube voltage, current, and electric power are 105 kV, 0.5 mA, and 50 W, respectively. Using a 3-mm-thick aluminum filter, the x-ray intensity is 26.0 μGy/s at 1.0 m from the source, with a tube voltage of 60 kV and a current of 0.50 mA. Because the peak photon energy is approximately 35 keV using the filter with a tube voltage of 60 kV, the bremsstrahlung x-rays are absorbed effectively by iodine-based contrast media with an iodine K-edge of 33.2 keV. Magnification angiography is performed by threefold magnification imaging with a computed radiography system using iodine-based microspheres 15 μm in diameter. In angiography of nonliving animals, we observe fine blood vessels approximately 100 μm with high contrasts. [ABSTRACT FROM AUTHOR]