Novel X-ray Sources for Medical Imaging: Making Old Physics Do New Tricks

The diagnosis of medical conditions often relies on medical imaging. Imaging applies basic physics and the techniques deployed have often found their origin in experimental methods. While some of these imaging modalities are new and have rapidly evolved, x-ray imaging has remained relatively stagnant since the introduction of Computed Tomography (CT) and more recently digital x-ray detectors. The availability of low-noise detectors, high speed desk-top computers and new algorithms offers incremental improvements on established x-ray imaging, but also challenges the practitioners in optimally deploying these resources as a primary concern is patient lifetime dose. New x-ray sources are often needed for advanced imaging approaches such as digital tomosynthesis, phase contrast imaging or improved interventional radiology. These novel sources often rely on field enhanced emission and carry new challenges into clinically deployed devices including ultra high vacuum, high voltage switching and the need for active feedback controls. I will describe some of these challenges, the regimes of operation under consideration by various groups, and the practical implications of the physics parameters to radiology.