High resolution quantitative relaxation and diffusion mri of three different experimental brain tumors in rat

Abstract

The potential of quantitative parameter images of the relaxation times T₁ and T₂, the proton density p and the apparent diffusion coefficient (ADC) to characterize three different experimental rat brain tumors (F98 glioma, RN6 Schwannoma, and E376 neuroblastoma) was studied. All parameter values, as determined in histologically confirmed regions 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 T₂ delivered statistically significant (P < 0.01) differentiation between tumor and edema. Multidimensional parameter combinations improved differentiation between different tissues. However, the three tumor types could not be differentiated. All parameter maps allowed the identification of the whole tumoredema area. On T₂ images, edema could be identified best, whereas the tumor itself was hardly visualized. In many cases, tumor presentation using T₁ maps corresponded best with histology, nevertheless suffering from a poor tumoredema differentiation.