The disclosed CT scanner includes a tomography system for generating data during a scan. The tomography system includes a detector characterized by at least one afterglow amplitude and at least one afterglow time constant, and a sampling device for generating a plurality of samples x.sub.i for all i from zero to MAX minus one of the detector output signal. The scanner also includes a set of N sub-processors for processing the samples x.sub.i, each of the sub-processors being represented by a unique integer q selected from zero to N minus one and receiving only the samples X.sub.iN+q. Each sub-processor includes a device for generating a compensated signal according to a function of at least a portion of the received samples and parameters representative of the afterglow amplitude and the afterglow time constant.