Multimodality stereotaxic correlation between XCT, PET, MRI and histology for tumoral tissue evaluation in the brain

This paper presents the design and implementation of a protocol and software system which, after acquisition and transfer, allows the registration and combination of images and data from various and complementary biomedical imaging modalities (X C T , P E T , M R I ). This combination is initially used for locating, inside the referential of a commercial stereotaxic frame, and either on morphological and/or metabolical grounds, the best target contender (i.e. the highest grade tumor tissue) for neurosurgical biopsy. Following initial localization, the system is also used to locate the biopsy samples into the multimodality volume, and for correlating the actual histology findings with the relative and/or modelled (dynamic acquisitions) data values at the samples locations. For now, we mostly rely on XCT and ¹⁸FDG PET for locating the ´metabolical center´ of a tumor, later on we will also use other PET tracers and more of MRI data. The system, which deals with file management, multimodality image registration & display, and pharmacokinetic data modeling, should be even more routinely used when PACS becomes available to link all our imaging equipments.