Refraction-enhanced x-ray imaging of mouse lung using synchrotron radiation source.

The low divergent x-ray beam from the third-generation synchrotron radiation source such as SPring-8 enables us to observe refraction of x rays that is in the range of microradians. Under an experimental condition for which ray optics is a good approximation, we found that the refraction produces a high-contrast projection image of a mouse when it was recorded at 6.5 m behind the specimen. Especially, the lung is visualized far better than with the conventional imaging which utilizes absorption of x rays. This is a promising new technique for the diagnosis of diseases in the human lung with a low radiation dose.