Download citation
Download citation
link to html
A high-sensitivity HARPICON camera was developed for medical X-ray imaging using a fluorescent screen. It is an avalanche-multiplication-type image pick-up tube and is 32 times more sensitive than conventional tubes. The camera also has a wider dynamic range than conventional medical-imaging cameras because a maximum output signal current of 2.3 μA is obtained and, in high-illumination-intensity regions, photocurrent is not proportional to illumination intensity. The fluorescent screen is an intensifying screen of the type used for radiographic screen-film combinations in medical examination. An X-ray image on the screen is focused on the photoconductive layer of the pick-up tube using a coupling lens with f/0.65. Experiments were performed using monochromated X-rays at the Photon Factory. An image of a spatial resolution test chart was taken in a 525 scanning-line mode of the camera. The chart pattern of 5 line-pairs mm−1 (spatial resolution of 100 μm) was observed at an X-ray input field of 50 × 50 mm. Real-time digital images of the heart of a 12 kg dog were obtained at a frame rate of 60 images s−1 after injection of a contrast medium into an artery. The images were stored in digital format at 512 × 480 pixels with 12 bits pixel−1. High-spatial-resolution and high-contrast images of coronary arteries were obtained in aortography using X-rays with energy above that of the iodine K edge; the image quality was comparable with that of conventional selective coronary angiography.
Follow J. Synchrotron Rad.
Sign up for e-alerts
Follow J. Synchrotron Rad. on Twitter
Follow us on facebook
Sign up for RSS feeds