Comparison of histopathological finding with diffusion-weighted imaging, perfusion MR and MR spectroscopy in the grading of cerebral gliomas.

The aim of this study is to research the usefulness of functional MR techniques,which is a noninvasive approach, in the grading of cerebral gliomas by comparinghistopathologic grading with grading of gliomas using Diffusion MR, Perfusion MR andMR spectroscopy techniques.20 patients who were diagnosed with glial tumor by means of operation orstereotactic biopsy (4 grade 2, 5 grade 3 and 11 grade 4) were included in this study. All thepatients were evaluated by means of conventional MR, diffusion MR, MR spectroscopyand perfusion MR imaging before the interventional procedure.The effect of the mass, edema, bleeding, necrosis, cystic area and contrastenhancement were evaluated by conventional MR. With diffusion MR, Apparent diffusioncoefficient (ADC) measurements were conducted at the values of b1000 mm²/sec. Choline(Cho), N-acetyl aspartate (NAA), Creatine (Cr), Cho/Cr, Cho/NAA and Lipid-Lactat (LL)metabolites were evaluated by MR spectroscopy, and relative cerebral blood volume(rCBV), relative cerebral blood flow (rCBF) and mean transit time (MTT) values werecalculated with dynamic susceptibility contrast enhanced (DSC) MR perfusion technique.At the end of the evaluation between low and high grade glial tumors, nostatistically meaningful difference was observed among tumoural, peritumoural edema andnormal parancima (ADCtm, ADCpte and ADC np) ADC values. Between high and lowgrade glial tumour?s TmLL, rCBV and rCBF values were statistically meaningful differencewhich was increasing at high grade, but no meaningful difference was observed betweenMTT values.Diffusion MR, Proton MR and perfusion MR are useful functional MR methods inthe grading of glial tumors, and they provide more information in comparison toconventional MRG. rCBV measurement is the best parameter for the evaluation of grading.The combination of ADC, LL, rCBV and rCBF will provide the best result in the gradingof glial tumors.Key Words: cerebral glial tumors, grading, diffusion MR, MR spectroscopy,Perfusion MR