Beyond Biopsy: A Synergistic Approach To Brain Tumor Characterization Using Diffusion-Weighted Mri And Proton Mr Spectroscopy

Background: Non-invasive differentiation of benign and malignant brain tumors remains a significant clinical challenge. Conventional MRI, while sensitive, often lacks histopathological specificity. This study evaluates the synergistic diagnostic performance of advanced MRI techniques - Diffusion-Weighted Imaging (DWI) and Magnetic Resonance Spectroscopy (MRS) - in characterizing brain tumors, using histopathology as the gold standard.

Material and Method: This prospective observational study included 50 patients with suspected brain lesions. All patients underwent 3T MRI, including multi-sequence conventional imaging, axial DWI (b-values 0 and 1000 s/mm²) for Apparent Diffusion Coefficient (ADC) mapping, and multi-voxel MRS (TE 35/144 ms). Key metabolite ratios (Cho/Cr, Cho/NAA, NAA/Cr) and ADC values were calculated from tumoral and peritumoral regions. These imaging findings were directly correlated with post-surgical histopathological diagnoses.

Result: Histopathology identified 35 malignant (70%) and 15 benign (30%) lesions. Malignant tumors demonstrated significantly lower mean ADC values and higher Choline (Cho) to Creatine (Cr) ratios. Receiver Operating Characteristic (ROC) analysis identified the Cho/Cr ratio as the most robust biomarker, yielding an Area Under the Curve (AUC) of 0.932 with a sensitivity of 94.3% and specificity of 86.7% at a cut-off of 1.72. The tumoral ADC value was also a strong differentiator (AUC 0.898), with a cut-off of 0.85 providing 94% sensitivity and 75% specificity. The combined use of DWI and MRS demonstrated a diagnostic accuracy of 86.0%, a sensitivity of 91.4%, and a specificity of 73.3%.

Conclusion: The integration of DWI and MRS provides a reliable and accurate non-invasive method for differentiating malignant and benign brain tumors. The Cho/Cr ratio, in particular, serves as a powerful and specific biomarker for malignancy. This synergistic approach enhances diagnostic confidence, aids in pre-surgical planning, and can help guide targeted biopsies.