Objective <p>This study aimed to characterize the magnetic resonance imaging (MRI) features of ependymal tuberculosis in patients with intracranial tuberculosis.</p> Methods <p>A retrospective analysis was performed on 21 patients diagnosed with ependymal tuberculosis, defined as direct ventricular involvement caused by <i>Mycobacterium tuberculosis</i> infection, between July 2019 and May 2024. Craniocerebral MRI findings were reviewed, and the imaging characteristics and their temporal progression were systematically evaluated.</p> Results <p>Two distinct MRI patterns of ependymal tuberculosis were identified: nodular and mixed types. The nodular type was characterized by intraventricular nodular lesions demonstrating isointensity on T1-weighted imaging (T1WI), iso- to hypointensity on T2-weighted imaging, mild hyperintensity on T2 fluid-attenuated inversion recovery imaging, and absence of diffusion restriction on diffusion-weighted imaging. On contrast-enhanced T1WI, the nodules demonstrated either homogeneous or ring enhancement. The mixed type was characterized by intraventricular nodules associated with linear thickening of the ventricular wall. Both the nodules and the thickened ependymal lining demonstrated homogeneous or ring enhancement on contrast-enhanced T1WI. Leptomeningeal tuberculosis was identified as linear or nodular meningeal thickening involving the basal cisterns, Sylvian fissures, or cerebral convexities. In patients with concomitant parenchymal tuberculosis, nodular or ring-enhancing lesions were observed within the cerebral, cerebellar, or brainstem parenchyma and were occasionally associated with surrounding edema. Following anti-tuberculosis therapy, progression of ependymal tuberculosis was observed in 13 of 21 patients, whereas improvement was observed in 8 patients. Disease progression was characterized by enlargement of pre-existing intraventricular nodules, which in some cases resulted in localized hydrocephalus. Improvement was characterized by reduction in nodule size.</p> Conclusion <p>MRI findings of ependymal tuberculosis include homogeneously or ring-enhancing intraventricular nodules, with or without associated linear ependymal thickening, and possible development of hydrocephalus. Despite anti-tuberculosis therapy, a substantial proportion of patients may exhibit paradoxical worsening characterized by enlargement of pre-existing lesions.</p> Clinical trial <p>Not applicable.</p>