A 38-year-old right-handed male presented with left glioblastoma, suffering from weakness in his right upper and lower extremities. MRI examination revealed an intra-axial tumor in the left temporal-parietal region. His language function was normal. The FA map showed decreased intralesional FA value, indicating the infiltration and destruction of WM tracts. The color-coded map showed complete disruption of the WM tracts of inferior fronto-occipital fasciculus (IFO) fibers. 3-D fiber tractography showed the intact left corticospinal tract (CST) in close relation to the lesion. The left CST was shown to be compressed and deviated medially by the mass lesion. The left arcuate fasciculus (AF) was seen away from the lesion, and unaffected by the same. Normal intact left-sided CST, IFO and AF tracts are shown for comparison. The tumor was resected maximally, avoiding the CST and AF, and was followed by chemoradiation (Figure ).
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.