Iterative reconstruction algorithms in nuclear medicine

Iterative reconstruction algorithms produce accurate images without streak artifacts as in filtered backprojection. They allow improved incorporation of important corrections for image degrading effects, such as attenuation, scatter and depth-dependent resolution. Only some corrections, which are im portant for accurate reconstruction in positron emission tomography and sin gle photon emission computed tomography, can be applied to the data before filtered backprojection. The main limitation for introducing iterative algo rithms in nuclear medicine has been computation time, which is much longer for iterative techniques than for filtered backprojection. Modern algorithm s make use of acceleration techniques to speed up the reconstruction. These acceleration techniques and the development in computer processors have in troduced iterative reconstruction in daily nuclear medicine routine. We giv e an overview of the most important iterative techniques and discuss the di fferent corrections that can be incorporated to improve the image quality. (C) 2001 Elsevier Science Ltd. All rights reserved.