Towards high-sensitivity and low-dose medical imaging with laser x-ray sources

Phase contrast X-ray imaging can be much more sensitive to soft tissue lesions than conventional absorption contrast X-ray imaging, being a potential game changer for medical imaging. A phase contrast method well suited for clinical implementation is the grating interferometry. We show that by using μm period multi-meter long interferometers one can strongly increase the phase sensitivity and lower the dose towards soft tissue imaging applications such mammography. Conventional X-ray tubes do not provide, however, sufficient X-ray flux for clinical imaging with such long interferometers. Instead, 100-TW class lasers could produce highly directional and intense X-ray sources ideal for high sensitivity medical interferometry. We present the X-ray source characteristics required for clinical interferometry, advantages and disadvantages of betatron versus inverse Compton scattering sources for clinical application, and some practical considerations towards laser based interferometric medical imaging.