Tissue Characterization Using Intrinsic NMR Parameters and a Hierarchical Processing Algorithm

The multiparametric nature of NMR imaging allows the same section to be displayed in many different ways by either adjusting acquisition parameters or calculating additional images, creating a possibly overwhelming data set. The need for this many images may be reduced by creating tissue type maps where each tissue is identified according to its characteristic NMR parameters and painted using a color code. Although T1 and T2 values for normal tissue are reproducible, variability among patients, the wide range of T1,T2 and N(H) values for abnormal tissue and partial volume averaging make the determination of tissue signatures difficult without significant operator intervention. A hierarchical processing algorithm, pyramidal segmentation, allowing simultaneous analysis at multiple levels of spatial resolution provides the basis for a tissue mapping algorithm with significantly reduced operator supervision.