Three-dimensional imaging utilizing scattered radiation

An algorithm for 3-D image reconstruction in nuclear medicine is proposed in which scattered radiation, rather than multiple projected images, is used for determination of the source depth within the body. Images taken from numerous energy windows are combined for reconstruction of the source depth in the body. The singular value decomposition of the kernel matrices is used to break the reconstruction problem into distinct channels which relate energy spectra to source depth distributions. Based on this analysis, a nonlinear (and noniterative) reconstruction algorithm is proposed and tested which avoids nodal patterns and blurring. The algorithm does not degrade spatial resolution in the imaging plane, provides depth resolution with standard deviation of 4 cm without requiring any camera motion, and produces significant attenuation correction in the reconstructed source distribution. The results suggest that the algorithm might have great value when incorporated into standard SPECT (single photon emission computed tomography) algorithms.<>