Large lung specimen imaging full-field micro-CT using a high-megapixel single lens reflex camera and synchrotron radiation

We have been developing large-field and high-resolution x-ray micro-CT systems using a 36M-pixel digital single lens reflex camera. The systems are highly specialized for large human lung specimen imaging of centimeter-sized objects with micrometer-range spatial resolution. The x-ray detector systems consist of a fluorescent screen for converting x-rays to a visible image, a pair of two interchangeable lenses, and the camera. The optical magnification in the lens system is determined using a ratio of two lens focal lengths. The lens coupling efficiency from the fluorescent screen to the camera through the lenses is important for high sensitivity. It is also determined by the two lenses. By changing the lens combination, widely various magnifications and sensitivities are readily obtainable. After the development of prototype systems for determining an optimum structure of an x-ray detector, a new practical system will be developed for higher sensitivity and higher resolution imaging.