A 34-year-old right-handed female developed an episode of partial epilepsy with transient language disorder. She recovered completely after few minutes of a seizure episode. MRI showed the left insular lesion characteristic for low-grade glioma. Pre-operative DTI was done to demonstrate the relationship of a lesion to eloquent areas to allow maximum tumor resection and to avoid tumor recurrence and damage to vital areas, such as language and motor function. Axial whole brain tractography showed destruction and distortion of the left frontal fibers and the left IFO tract. Anterior part of arcuate fasciculus (AF) was seen in close relation to the anterior-superior part of the lesion. The left CST was intact, yet medially deviated (Figure ).
A 37-year-old man was admitted to our hospital with weakness of the right limbs and speech and memory loss. Muscle strength in the right-side extremities was grade 4 according to Lovett's testing. A mass lesion involving the left basal ganglia, thalamus and internal capsule was detected on routine magnetic resonance imaging (MRI) with low T1-signal intensity and high T2-signal intensity. The DTI showed a lower value of FA in the affected white matter (0.08-0.24) compared to the contralateral side. DTI-based fiber-tracking displayed a reduced fiber tract on the left CST, and partially interrupted in the lesion area (fig. ). Fiber bundles slightly increased but were still interrupted using an FA cut-off value of 0.10 for fiber-tracking. Diagnosis of diffuse astrocytoma was made after biopsy and histopathological results.