Abstract: An opaque, generally flat flexible cassette is provided which receives and holds a storage phosphor screen while the screen is radiographed. The cassette has sufficient flexibility to be wrapped around an object to be radiographed. The cassette has a light-tight sealing device at or near its open end. The sealing device allows the cassette to be placed in either an open position for receiving or discharging the storage phosphor screen, or a closed position for holding the imaging storage medium therein during radiographing and transport. The cassette is designed so that the storage phosphor screen is discharged from the cassette without being physically handled by a person or being exposed to ambient light.