“…X-ray phasecontrast CT imaging techniques are based on the phase shift of X-ray waves that occurs due to refraction and have approximately a thousand-fold higher sensitivity for detecting light elements, such as hydrogen, carbon, nitrogen and oxygen, than conventional X-ray absorption-contrast techniques (Momose et al, 1996). In fact, X-ray phase-contrast CT imaging has successfully visualized the microstructure of normal and pathological tissues including brain (Connor et al, 2009), kidney (Wu et al, 2009), artery (Shinohara et al, 2008), blood vessel (Hu et al, 2012) and eye (Hoshino et al, 2011(Hoshino et al, , 2012. In addition, the phase factor in the complex refractive index, on which this imaging contrast is based, is proportional to mass density (Momose et al, 1996;Hoshino et al, 2011).…”