Perfusion Weighted Imaging Directed Proton MR Spectroscopy: A New Approach to Identify Oligodendroglial Genotypes

Sanjeev Chawla¹, Yu Zhang², Jaroslaw Krejza¹, Sumei Wang¹, Gurpreet Kapoor³, Sangeeta Chaudhary¹, Arastoo Vossough¹, Donald O' Rourke³, Elias R. Melhem¹, Harish Poptani¹

To identify oligodendroglial genotypes, 1H-MRS voxels guided by perfusion weighted imaging were analyzed from 34 patients [1p/19q deletion (Group I, n=19), and intact alleles (Group II, n=15)]. 1H-MRS grid was overlaid on CBV maps. CBV values were obtained by drawing ROIs from the tumor and were normalized to contralateral white-matter to obtain relative rCBV values. 1H- MRS indices were computed from maximum rCBV regions and logistic regression analyses was performed. Using a combination of maximum rCBV and Cho/Cr from the maximum rCBV ROI resulted in a sensitivity of 73% and specificity of 84% in distinguishing the two groups of oligodendrogliomas.