A cassette (10) for photo-stimulable ("PSL") radiography, comprising a flat rigid base (12) and a cap (14) for the base which is releasably securable thereto so as lighttightly to cover a layer of PSL material applied to the inside face of the base, which cassette comprises a rigid removable PSL plate (13) which can freely rest on the base plate within the cap, and which is arranged for absorbing a portion of the X-ray radiation image which will expose the PSL layer on the base and which has four extensions (17) for its lifting, the cap (14) and the removable PSL plate (13) being arranged in such a way that both the cap alone, and the cap together with the PSL plate can be lifted from the base, in order to allow the separate reading-out of the image of the base and of the PSL plate.