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.
A 67-year-old man was admitted to our hospital with a history of weakened left limbs and muscle twitching. On physical examination the muscle strength of the left upper limb was grade 2 and grade 4 on the lower limb. T2-weighted MRI revealed the lesion involving the right centrum ovale and part of the precentral gyrus. The FA value of the affected white matter was slightly lower (0.28) compared with the contralateral side (0.40). DTI-based fiber-tracking displayed a right CST passing through the lesion without interruption (fig. ). The patient refused surgery, therefore no histopathological diagnosis was made. However, an increased choline concentration (maximum choline/creatine and choline/N-acetylaspartate ratios of 3.04 and 4.51, respectively) was detected in the lesion with MRS study, which was highly suggestive of tumor.