| 摘要 |
A differential phase contrast imaging (DPCI) apparatus and an anode for an X-ray tube of such DPCI apparatus are proposed. The anode (39) comprises a rotatable anode disk (41) with a focal track region (51) close to a circumference (59) thereof. Upon impact of accelerated electrons, an X-ray (5) is emitted from a focal spot (53). The anode (39) further comprises a ring-like modulating absorption grid (55) fixedly connected to the anode disk (41). This modulating absorption grid (55) comprises wall portions (57) of an X-ray absorbing material and slits (67) between neighboring wall portions (57). Spacings between neighboring slits (67) are smaller than a width wf of the focal spot (53), for example smaller than 100 μm, preferable less than 20 μm, and the slits (67) have a width of less than 50 μm, preferably less than 10 μm. Upon rotation of the anode (39), the modulating absorption grid (55) may serve as a source grid in the DPCI apparatus, such that the generated electron beam (5) is periodically modulated. Accordingly, in such DPCI apparatus, a phase-shift grid and a phase analyzer grid may be stationary thereby avoiding a risk of positioning inaccuracies e.g. upon moving of the components of the DPCI apparatus during X-ray imaging. |
