Abstract: A radiation imaging device of the type employing a scintillator and a position-sensitive photomultiplier tube eliminates or reduces edge effects and thereby increases the linear field of view by compensating for nonlinearities which distort an image close to the edge. Specifically, (1) a light guide is placed about the edge of the scintillator to channel light that would otherwise be reflected from the edge of scintillator to a light absorbing material so that edge reflected light is not detected by the position-sensitive photomultiplier tube and (2) variable resistors are employed to compensate for distortions in the image caused by current leakage along the edge of the position-sensitive photomultiplier tube.

Abstract: An imaging apparatus with a flexible light guide which a surgeon can easily manipulate within the patient to control the field of view. Specifically, a scintillator receives radiation rays and converts these radiation rays into light signals at a position inside the body. A flexible bundle of optical fibers optically connected to the scintillator, channels the light signals from the scintillator to a position sensitive light signal detector located outside the body. The position sensitive light signal detector creates a digital signal to relay the position information about the detected event to a computer which accumulates these digital signals, converts these digital signals into images and displays the images.