Diagnostic Utility of Magnetisation Transfer Ratio (MTR) in Differentiating Tuberculoma from Neurocysticercosis in Ring-Enhancing Brain Lesions: A Cross-Sectional MRI-Based Study

Abstract

Introduction: Intracranial ring-enhancing lesions are a frequent imaging finding in patients presenting with seizures or other neurological symptoms. In regions like India, tuberculoma and neurocysticercosis (NCC) are the most common causes, often sharing overlapping features on MRI. Accurate differentiation is essential, as NCC typically responds to antiparasitic and antiepileptic therapy, while tuberculoma requires long-term antitubercular treatment. Traditional MRI sequences may not provide sufficient distinction. Magnetisation Transfer Imaging (MTI), particularly through Magnetisation Transfer Ratio (MTR) measurement, offers a quantitative tool that reflects underlying tissue composition, helping differentiate between infectious etiologies.

Aim and Objective: To assess the effectiveness of MRI using Magnetisation Transfer Ratio (MTR) in accurately differentiating tuberculoma from neurocysticercosis in patients presenting with ring-enhancing lesions on brain imaging.

Materials & Methods: This was a cross-sectional, observational study conducted over 1.5 years at Sree Balaji Medical College and Hospital, Chennai. Thirty patients with ring-enhancing brain lesions and clinical suspicion of CNS granulomas were evaluated. MRI was performed with MTR sequences, and values were compared between tuberculoma and NCC subtypes (colloid vesicular, granular nodular, vesicular). ANOVA and post-hoc statistical tests were applied to determine significance.

Results: The mean MTR for tuberculoma was 18.4 ± 2.46. Among NCC subtypes, colloid vesicular showed 11.3 ± 1.13, granular nodular 21.5 ± 1.57, and vesicular 13.9 ± 4.5. ANOVA indicated significant intergroup differences (p < 0.00001), while post-hoc analysis validated key pairwise distinctions, supporting MTR’s role in lesion differentiation.

Conclusion: MTR is a reliable, non-invasive imaging biomarker that significantly improves diagnostic accuracy in distinguishing tuberculoma from different NCC stages, facilitating appropriate treatment planning in endemic regions.