Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Stefan Michael Schneider

Herfried Karl Wieczorek

Josef Lauter

Olaf Such

Francisco Morales Serrano

Gereon Vogtmeier

Wolfgang Eckenbach

Peter Flisikowski

The invention relates to an anti-scatter grid for the absorption of X-rays, wherein the wall elements () of the grid consist of a thermoplastic () with heavy metal particles () embedded therein. By using such a mixture, it is possible to produce the wall elements by injection molding, whereby even very finely and complicatedly shaped, in particular two-dimensional, grids may be produced in cost-effective manner.

Grid for the absorption of X-rays

A data acquisition system which includes data generating and processing units (), each of which includes a respective data source () which serves to generate data. The data each time generated is processed by means of associated data processing means () in such a manner that each time a digital data word which comprises at least two bits is presented for output. The output of the digital data words takes place in synchronous-parallel fashion in dependence on first control signals (). Shift registers () which are coupled to one another so as to form a chain propagate the digital data words in synchronous-parallel fashion in dependence on second control signals () and are coupled to a respective associated data generating and processing unit ().

Data acquisition system

The invention relates to a grid () for the absorption of X-rays (). An anti-scatter grid for reducing the scattered radiation is readily manufactured by arranging a plurality of layers containing wire elements () that are spaced apart and an appropriate ruggedness is achieved also for large-area X-ray detectors.

An X-ray detector that includes a sensor matrix and a scintillator arrangement and in which wire elements are spaced apart in layers A and B in order to reduce the crosstalk in neighboring detector elements. Scintillators are inserted at least partly in the grid openings formed.

X-ray detector

The invention relates to a method for scatter correction while forming a computed X-ray tomogram. The distribution of the scattered radiation is determined by detector cells ( &prime;) which, because of the measuring method carried out, are shielded from direct irradiation in a two-dimensional, multi-cell detector field ( ). This distribution is used to perform a scatter correction in the neighboring, directly irradiated detector cells ( ). Furthermore, scatter correction can be performed by computer simulation of the scatter processes. To this end, use is preferably made of a Monte Carlo method and the effect of the geometry and the material composition of the measuring arrangement, of the patient size, of the irradiated tissue and the like, is taken into account.

Device and method for forming a computed X-ray tomogram with scatter correction

The invention relates to a detector for the detection of electromagnetic radiation ( ), including scintillators (S -S ), a photosensor device (F -F ) and an intermediate layer ( ). The optical crosstalk due to multiple reflection in the intermediate layer is prevented in that at least parts of the intermediate layer ( ) contain substances absorbing electromagnetic radiation ( ).

Detector for the detection for electromagnetic radiation

The invention relates to a computer tomograph provided with a charge-integrating read amplifier having a plurality of gain factors for a data acquisition system as well as a control circuit for the gain factor. In order to avoid noise in addition to the shot noise in computer tomographs of this kind and also to avoid degrading of the DQE (Detection Quantum Efficiency), according to the invention it is proposed that the control circuit automatically selects the gain factor in dependence on the expected integrated input signal of the next frame, the expectation being based on the maximum possible relative variation of the integrated input signal between two successive frames.

Computer tomograph with a multi-stage charge-integrated read amplifier

In order to increase the ruggedness and the scattered radiation attenuation quality, a grid ( ) with comb elements ( ) which absorb electromagnetic radiation and are intended to form a grid is constructed, in such a manner that comb lamellae ( ) extend transversely of an associated comb base surface which supports the comb lamellae ( ).

The invention relates to a computed tomography apparatus which includes a radiation source, a detector device and an analog-to-digital converter for converting the detector output signals into digital values. In order to realize a computed tomography apparatus in which the number of binary positions required for the encoding of the signal entering the analog-to-digital converter is reduced while using simple components which operate with a high degree of reliability, use is made of a read-out amplifier (,) which precedes the analog-to-digital converter (,), has a plurality of gain factors and a control system (,) for the relevant gain factor which, when a predetermined limit value of the integrated input signal is reached, automatically selects an appropriate, each time lower gain factor for the step-wise linear approximation of a proportional ratio between the digital values and the square root of the detector output signals.

Computed tomography apparatus

A computer tomograph detector for the detection of electromagnetic radiation transmitted by an object, which detector includes at least one detector row which consists of a plurality of detector elements, each detector element including a scintillator for converting radiation of a first energy level into radiation of a second energy level, as well as a photosensor for converting the radiation into an electrical current, each photosensor being associated with an amplifier element, is extended in such a manner that it can include a plurality of detector rows while the electronic noise is nevertheless reduced and at the same time a higher DQE is obtained; this is achieved by arranging a plurality of photosensors and the associated amplifier elements on the same substrate in integrated semiconductor technique.

Computer tomograph detector

In order to manufacture a scintillator layer for a detector for the detection of electromagnetic radiation, transmitted by an object, which has a high spatial resolution and only a slight interaction between the scintillator elements, it is proposed to pour a molten mass of a radiation-absorbing metal, having a melting point below 350&deg; C., into intermediate spaces which extend vertically between neighboring scintillator elements.

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Aachen, Germany

Stefan Michael Schneider