A CLINICAL PERSPECTIVE OF ACCELERATED STATISTICAL RECONSTRUCTION

Although the potential benefits of maximum likelihood reconstruction h ave been recognised for many years, the technique has only recently fo und widespread popularity in clinical practice, Factors which have con tributed to the wider acceptance include improved models for the emiss ion process, better understanding of the properties of the algorithm a nd, not least, the practicality of application with the development of acceleration schemes and the improved speed of computers, The objecti ve in this article is to present a framework for applying maximum like lihood reconstruction for a wide range of clinically based problems, T he article draws particularly on the experience of the three authors i n applying an acceleration scheme involving use of ordered subsets to a range of applications, The potential advantages of statistical recon struction techniques include: (a) the ability to better model the emis sion and detection process, in order to make the reconstruction conver ge to a quantitative image, (b) the inclusion of a statistical noise m odel which results in better noise characteristics, and (c) the possib ility to incorporate prior knowledge about the distribution being imag ed, The great flexibility in adapting the reconstruction for a specifi c model results in these techniques having wide applicability to probl ems in clinical nuclear medicine.