POTENTIAL OF MR SPECTROSCOPY IN DIFFERENTIATING BETWEEN LOW GRADE AND HIGH GRADE CEREBRAL GLIOMAS KEEPING HISTOPATHOLOGY AS GOLD STANDARD

Abstract

Objective: To determine the diagnostic accuracy of magnetic resonance spectroscopy (MRS) using choline-creatine (Cho/Cr) ratio for preoperative grading of gliomas, taking histopathology as the gold standard. 

Study design: Cross-sectional study.

Place and Duration of study: Radiology department, Armed Forces Institute of Radiology, Rawalpindi, Pakistan from Oct 2023 to April 2025.

Methodology: Thirty-two patients with MRI-detected supratentorial gliomas underwent proton MR spectroscopy (¹H-MRS) using a 1.5 T MRI scanner. The Cho/Cr ratio was measured from the solid, enhancing component of the tumour. A ratio > 1.2 was considered suggestive of high-grade glioma, while ≤ 1.2 indicated low-grade. Findings were compared with histopathological grading. Diagnostic parameters including sensitivity, specificity, predictive values, accuracy, and p-value were calculated.

Results:  Of 32 patients, 29 were male and 3 females (mean age = 44.1 ± 12.7 years; range 17–65 years). Based on MRS, 23 were labelled high-grade (Cho/Cr > 1.2) and 9 low-grade (≤ 1.2). Histopathology confirmed 25 high-grade and 7 low-grade gliomas. True positives = 21, false positives = 2, false negatives = 4, true negatives = 5. Sensitivity = 84.0%, specificity = 71.4%, PPV = 91.3%, NPV = 55.6%, accuracy = 81.3%. The Chi-square test value was 6.22 (p = 0.013).

Conclusion:  MRS is a reliable, non invasive, radiological investigation for differentiating between high-grade and low-grade gliomas. The MRS parameter Cho/Cr ratio serves as a reliable metabolic parameter in determining the tumor grade and shows comparable results with histopathological diagnosis.