Fig. 2

The LAC as determined by bi-linear CT calculation and the theoretical mixture model. MRAC-derived LAC values are shown for comparison only and were not used to correct PET data. CT and mixture model are closely correlated, showing an increase of approximately 2% up to 66 mM. The MRAC segmentation routine fails to determine accurate LAC at higher mM concentrations due to T1-shortening effects caused by the presence of high concentrations of GBCA