U.S. Philips Corporation

Wilhelmus J Welters

Johannes Marra

Jacob Wijdenes

Nicolaas P Willard

Edward W Young

Herman Stegehuis

Petrus W Linders

Lambertus G Fokkink

X-ray examination apparatus including a filter An X-ray examination apparatus (1) includes an X-ray source (2), an X-ray detector (5) and an X-ray filter (6). The X-ray filter (6) is arranged between the X-ray source and the X-ray detector. The X-ray filter (6) includes a plurality of filter elements (7) whose X-ray absorptivity can be adjusted by adjusting a quantity of X-ray absorbing liquid (30) present in individual filter elements (7). The filter elements are formed by substantially parallel plates (8), respective plates being provided with separating members (10) which project approximately transversely from the plane of such a plate. The filter elements are formed notably by parallel corrugated plates or by parallel plates provided with partitions extending transversely from the plates.

X-ray examination apparatus including a filter

An X-ray examination apparatus includes an X-ray source (1) for emitting X-rays. An object to be radiologically examined is arranged in an examination space. An X-ray detector (2) derives an image signal, for example an electronic video signal, from an X-ray image of the object. An X-ray filter locally attenuates the X-rays partly. The X-ray filter is arranged between the X-ray source and the X-ray detector and the X-ray filter is provided with filter elements whose X-ray absorptivity can be adjusted on the basis of an amount of X-ray absorbing liquid present within the individual filter elements. The X-ray examination apparatus includes an X-ray collimator for locally intercepting the X-rays. The X-ray collimator is arranged between the X-ray source and the examination space and is provided with collimator elements which can be switched between an X-ray transmitting state and an X-ray intercepting state. Individual collimator elements are filled with an X-ray intercepting liquid in the X-ray intercepting state. The amount of X-ray absorbing liquid present in the filter elements is controlled by application of an electric voltage to the relevant filter elements. The collimator elements are switched between the X-ray intercepting state and the X-ray transmitting state by means of an electric voltage which is applied to the relevant collimator elements.

X-ray examination apparatus including an x-ray filter

An X-ray examination apparatus (1) is provided with an X-ray source (2) and an X-ray detector (5) wherebetween there is arranged an X-ray filter (6) which includes filter elements (7) whose X-ray absorptivity can be adjusted by controlling the quantity of X-ray absorbing liquid (31) in individual filter elements (7). The filter elements (7) are formed by spaces between electrically conductive tracks (9) provided on parallel plates (8). The parallel plates are arranged in a reservoir (31) for the X-ray absorbing liquid. The liquid level in the vicinity of an electrically conductive track is controlled on the basis of an electric voltage applied to the relevant electrically conductive track (9).

An X-ray examination apparatus (1) includes a filter (4) which is arranged between the X-ray source (2) and the X-ray detector (3). The X-ray filter includes a large number of filter elements (5); the X-ray absorptivity of the filter elements can be adjusted by controlling the quantity of X-ray absorbing liquid (6) than individual filter elements. The filter elements are formed by metal capillary tubes or the wall of the capillary tubes, or the wall of the capillary tubes is provided with a metal layer (7). On the metal layer there is provided a dielectric layer (8) and the dielectric layer is covered by a coating layer (9). The dielectric layer is, for example a glass, parylene or polystyrene layer. The coating layer is, for example a Teflon, silane or siloxane layer. The dielectric layer can be dispensed with when a Teflon coating layer is used.

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Eindhoven, Netherlands

Wilhelmus J Welters