THE IMPACT OF SCATTERING AND PEAK SPECTRUM OF I-123 IN SCINTIGRAPHY BY I-123 MIBG

摘要

Metaiodobenzylguanidine (MIBG) scintigraphy is used to image tumors of neuroendocrine origin and study disorders of sympathetic innervation of the myocardium. Scintigraphic imaging methods offer the possibility of qualitative and quantitative assessment of tracer concentration. Accurate correction for the physical degrading factors (attenuation, scatter, partial volume effects) is demanded. An analytical study of the I-123 energy spectrum, scattering and attenuation contribution to the resulting image of an I-123 MIBG scintigraphy, has been undergone, so as to improve the data that could be collected by I-123-M1BG use. In this work, quantitative data were gathered at various source depths, volumes and crystal to phantom distances to determine the effect of these variables on source activity data. The final image is being extracted from the combination of three different images, each and every one being acquired by a different energy window. The middle one has been obtained from the main I-123 photopeak and the others, from the left and right peaks respectively. The problem of Compton scattering as the dominant photon interaction phenomenon and its impact on both the quality of clinical images and the accuracy of quantitative analysis is taken into consideration for a scatter modeling in non-uniform media.