Patent Number: 
Section: description

The production of an inventive detector arrayxe2x80x94as shown in FIG. 1xe2x80x94is based on a rectilinear layer 1 composed of scintillator material M. For example, the scintillator material M is of the type referred to as UFC, as described in U.S. Pat. No. 5,296,163. The height H of the layer 1 is approximately 0.1 cm. As shown in the result of FIG. 2, separating channels 3, which are parallel to one another and perpendicular to the plane of the drawing, in a second step, are sawed or milled into the layer 1 from above. Each separating channel 3 is a part of an intermediate area 5 by which individual scintillator elements 7 are separated from one another. The separating channels 3 have a depth that is smaller than the height H of the scintillator elements 7. The height h of remaining compounds 8 from scintillator material M between adjacent scintillator elements 7 is approximately 0.03 cm. Therefore, the connections 8 fashioned as bridges or webs are a part of the intermediate areas 5, so that scintillator material M is present in these intermediate areas 5. FIG. 3 shows the result of a third step of the production method. In this step, the separating channels 3, the side faces of the scintillator elements 7A situated most remote and the side faces that can be faced toward the X-rays 10 to be detected are filled or covered with a reflector material and/or absorber material R. The separating channels 3 thus become insulating areas 9 which reduce crosstalk between adjacent scintillator elements 7, 7A. FIG. 4 shows the end product resulting from a fourth step of the production method. In the fourth step, a substrate 13 having individual photo-electrical receivers 11 is optically coupled to the side of the scintillator elements 7 facing away from the X-rays 10. An optically transparent adhesive, for example, is used for this purpose. Respectively one photo-electrical transducer 11 is allocated to one of the scintillator elements 7 in position and size. The light quanta 15 generated by the arriving X-rays 10 in the scintillator elements produce an electrical signal in the respective photo-electrical transducers 11. Those electrical signal are supplied via contacts (not shown) of an evaluation electronic unit. X-ray quanta 16 radiating into the insulating area 9 also generate light quanta 17, 18, namely in the compound 8. These light quanta 17, 18 arrive at adjacent transducers 11. The end product of the production method shown in FIG. 4 shows an inventive one-dimensional detector array. Analogous to the FIGS. 2 and 3, separating channels and insulating areas are introduced perpendicular to the separating channels 3 or insulating areas 9 shown therein such that they intersect in order to generate a two-dimensional, matrix-like detector array 23 (see explanations of FIG. 5). In the inventive detector array 21, the scintillator layer 1 is not structured in full depth. A compound 8 or a web composed of scintillator material M remains between the individual pixels or scintillator elements 7. An optical separation of the pixels is still assured, although not in a complete manner. A large portion of the X-ray quanta striking the intermediate area 5 between two pixels is absorbed in the scintillator web, so that the efficiency of the detector array 21 is improved. The depth of the structuring depends on the level of the tolerable crosstalk and on the absorption properties of the scintillator material M. Some crosstalk is tolerable whenxe2x80x94given a constant and known crosstalkxe2x80x94the crosstalk effect, in the image reconstruction, is xe2x80x9ccalculated outxe2x80x9d of the computed tomography image by convolution with a suitable convolution kernel, for example. The absorption properties of the scintillator material M determine how many quanta are absorbed in the connection 8 or in the web. Approximately 50% of the arriving X-ray quanta are absorbed by a web having a thickness of only h=0.03 cm, for example, given an absorption coefficient of 10 cmxe2x88x921. These X-ray quanta contribute to the useful signal. Therefore, the quanta efficiency of the detector array 21 is increased in comparison to a detector array having pixels that are completely separated from one another. The spatial resolution of the detector array 21 is maintained at the same time. Such a detector array 21 is particularly advantageous in modern multi-slice computer tomography apparatuses having a number of separating channels. FIG. 5 shows a schematic plan view of an inventive two-dimensional detector array 23. It is composed, for example, of 6xc3x973 individual sensor elements arranged in three rows and six columns. The individual sensor elements each havexe2x80x94see the one-dimensional detector array 21 of FIG. 4xe2x80x94a scintillator element and an allocated photo-electrical receiver. As an example, three scintillator elements are referred to as 25, 27, 29. The detector array 23 is installed into a computed tomography apparatus (not shown) such that the rows are oriented in the (xcfx86-direction (detector channel direction) of the computed tomography apparatus, i.e., in the circumferential direction of an X-ray emitter rotating on a gantry. The columns extend in the z-direction, i.e., in the direction of the patient. In the two-dimensional detector array 23 of FIG. 5, scintillator material M is present in the intermediate areas 31 generating the insulation between the scintillator elements 25, 29 in one of the two array dimensions. In the second dimension, scintillator material M is not present in the intermediate area 33 between the scintillator elements 25, 27. The preferred and exemplary embodiments described in connection with the one-dimensional detector array 21 are also valid for the two-dimensional detector array 23. Although modifications and changes may be suggested by those skilled in the art, it is in the intention of the inventor to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of his contribution to the art.