HIGH-RESOLUTION QUANTITATIVE RELAXATION AND DIFFUSION MRI OF 3 DIFFERENT EXPERIMENTAL BRAIN-TUMORS IN RAT

The potential of quantitative parameter images of the relaxation times T-1 and T-2, the proton density rho and the apparent diffusion coeffi cient (ADC) to characterize three different experimental rat brain tum ors (F98 glioma, RN6 Schwannoma, and E376 neuroblastoma) was studied, All parameter values, as determined in histologically confirmed region s of interest (ROI), were higher in edema than in tumor, which in turn were elevated with respect to normal brain, ROI values of ADC and T-2 delivered statistically significant (P < 0.01) differentiation betwee n tumor and edema. Multidimensional parameter combinations improved di fferentiation between different tissues, However, the three tumor type s could not be differentiated, All parameter maps allowed the identifi cation of the whole tumor-edema area, On T-2, images, edema could be i dentified best, whereas the tumor itself was hardly visualized, In man y cases, tumor presentation using T-1, maps corresponded best with his tology, nevertheless suffering from a poor tumor-edema differentiation .