Fig. 6.

High-grade glioma. Conventional MRI: a, b Axial and coronal post-contrast T1W sequences, showing a well-defined lesion at the ponto-medullary junction. Multiparametric MRI: c ADC map demonstrates low ADC (590 × 10⁻⁶ mm² s⁻¹). d PWI shows high perfusion (rCBV 2.8, arrow). e, f MRS shows a high Cho/Cr ratio (2.9, arrow), low NAA/Cr ratio and presence of lipid peaks. MRI findings of a low ADC (< 1000 × 10⁻⁶ mm² s⁻¹), high rCBV (> 2) and high Cho/Cr ratio (> 1.8) are consistent with a high-grade glioma rather than a granuloma or abscess. The presence of high choline levels in the perilesional area (not shown) favour high-grade glioma over a metastatic lesion. In this patient, an initial biopsy was inconclusive and as a result of the multiparametric MRI findings, a decision to undergo further biopsy was overturned. The patient underwent radiotherapy for presumed glioblastoma