Toward clinical X-ray phase-contrast CT: Demonstration of enhanced soft-tissue contrast in human specimen

Objectives: X-ray computed tomography (CT) using phase contrast can provide images with greatly enhanced soft-tissue contrast in comparison to conventional attenuation-based CT. We report on the first scan of a human specimen recorded with a phase-contrast CT system based on an X-ray grating interferometer and a conventional X-ray tube source. Feasibility and potential applications of preclinical and clinical phase-contrast CT are discussed. Materials and Methods: A hand of an infant was scanned ex vivo at 40 kVp tube voltage. The simultaneously recorded attenuation and phase-contrast CT images were quantitatively compared with each other, by introducing a specific Hounsfield unit for phase-contrast imaging. Results: We observe significantly enhanced soft-tissue contrast in the phase images, when compared with the attenuation data. Particularly, tendons and ligaments appear with strongly increased contrast-to-noise ratio. Conclusions: Our results demonstrate the huge potential of phase-contrast CT for clinical investigations of human specimens and, potentially, of humans. Because the applied technique works efficiently with conventional X-ray tubes and detectors, it is suitable for the realization of preclinical and clinical phase-contrast CT systems.