Image Reconstruction in Optical Tomography

Monday, March 17, 1997 - 11:00am - 12:00pm
Keller 3-180
S. R. Arridge (University College)
Optical Tomography is a new medical imaging modality that is at the threshold of realisation. A large amount of clinical work has shown the very real benefits that such a method could provide. At the same time a considerable effort has been put into theoretical studies of its probable success. At present there exist gaps between these two realms. In this paper, the underlying basis for the image reconstruction process is reviewed, and examples are presented that show the realistic resolution, contrast and specificity that may be expected. In particular we discuss problems of acquistion time, computational efficiency and reconstruction artefacts. We suggest in particular that both time-resolved, and intensity-modulated systems can reconstruct variations in both optical absorption and scattering, but that unmodulated, non-time-resolved systems are prone to severe artefact. Furthermore, classical back-projection style reconstructions are insufficient and iterative methods are required.