The invention relates to a semiconductor device with a semiconductor body comprising a CMOS image sensor with an active region having viewed in projection first sides and second sides perpendicular to the first sides said active region comprising a matrix of active pixels arranged in rows and columns, each pixel having a photosensitive region, the device further comprising a plurality of circuit elements for operating the pixel in the image forming process, the plurality of circuit elements comprising a first set of circuit elements for read-out of the columns and a second set of circuit elements for controlling the rows.According to the invention a first part of the plurality of circuit elements is positioned outside the matrix along one of the first sides and a second part of the plurality of circuit elements is positioned within the matrix of active pixels remote from the second sides. Preferably the first part elements comprises the read-out circuitry of the columns and the second part elements comprises the control circuitry of the rows, the latter preferably being distributed over a number of centrally positioned columns. A device according to the present invention is very suitable for X-ray medical imaging.