Gamma ray imaging by single grating aperture

A time varying coded aperture of containing single sinusoidal grating which is translated between the radiative source plane and the detector plane is discussed. To the detector, the aperture behaves as a variable frequency grating that scans the objects over a two dimensional frequency domain by changing its orientation and position. 1-131 isotope was used as the gamma ray source in the experiment. We used summation filtered back projection algorithm to reconstruct the image. The disc and annulus was reconstructed successfully. Because of this single grating aperture has simple geometry and easier data acquisition compared with Fourier aperture. We could use it as a gamma ray imaging device in nuclear medicine. The tomographic image capabilities of this system are discussed also.