Diffusion tensor imaging in brainstem tuberculoma.

Integrity of descending white matter tracts can be evaluated by diffusion tensor imaging. In rim-enhancing intraparenchymal lesions, this technique can assist in the differentiation of demyelinating disease from tumor or abscess. Diffusion tensor imaging characteristics of tuberculoma have not been previously reported to our knowledge. A patient with headaches, dizziness, and mild left-sided weakness underwent MRI with diffusion tensor imaging. A large, rim-enhancing lesion within the pons was discovered, which subsequently was diagnosed as tuberculoma. Tractography maps prepared from diffusion tensor imaging data revealed predominantly displaced descending fiber tracts in the region of the rim-enhancing lesion. A few tracts adjacent to the lesion appeared truncated, and this abnormal finding correlated to the patient's clinical deficit. The tractography characteristics of diffusion tensor imaging in this patient potentially are distinct from those seen with demyelinating lesions, which may show more extensive tract truncation. Together with the consonance of exam findings and tract truncation seen in this patient, tractography may prove useful in the diagnosis of suspected tuberculoma.