MR Perfusion Imaging as a Problem- Solving Tool for Differentiating High-grade Glioma and Tumefactive Demyelination: A Report of Two Cases

Abstract

Clinically, it is nearly impossible to differentiate between high-grade glioma, specifically Glioblastoma Multiforme (GBM), and Tumefactive Demyelination (TMD). Radiologically, distinguishing between GBM and TMD is challenging since they show similar findings on Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). To avoid invasive procedures that may increase patient morbidity, the use of MR perfusion imaging is highlighted in these case reports. We present two cases of young adult females with neurological deficits. The first case involves an 18-year-old female who presented with a dull, intermittent, holocephalic headache for eight months, along with heaviness and recent onset of pain in the right upper limb. MR spectroscopy revealed an increased choline/creatinine ratio at the margins of the lesion, measuring approximately 2.4, with a decrease in N-Acetylaspartate (NAA) and NAA/Creatinine. Based on these findings, the possibility of either high-grade glioma or TMD was considered. Further evaluation using perfusion imaging showed a substantial increase in the mean relative Cerebral Blood Volume (rCBV) within the lesion, suggesting a higher likelihood of high-grade glioma rather than TMD. Biopsy confirmed the diagnosis as high-grade glioma (GBM), revealing marked mitotic changes with nuclear pleomorphism and multinucleated cells. The second case involves a 22-year- old female who presented with left upper limb and lower limb weakness for 10 days. MR spectroscopy showed reduced NAA values and an elevated choline peak with small lactate at a few places. A choline/creatine ratio of 1.9 was obtained. On perfusion imaging, the observed mean rCBV values were substantially low (rCBV measuring approximately 1.07). Consequently, a final radiological diagnosis of TMD was considered. A biopsy confirmed the presence of inflammatory demyelination.