Quantification of microbubble concentration through x-ray phase contrast imaging

The use of microbubbles as a contrast agent for x-ray phase contrast imaging could both transform x-ray imaging into a “functional” modality and enable much needed monitoring of targeted drug delivery. To realize these benefits, it is essential to be able to quantify bubble concentration in a given tissue volume. We developed and validated a model that enables this to be achieved not only for phase-retrieved images obtained by processing multiple frames but also on “single-shot” images, a likely necessity in in-vivo implementations. Our experimental validation was based on analyzer-based imaging, but extension to other phase-based modalities is straightforward.