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 headache and weakened left limbs. Muscle strength on the left side was grade 4. Routine MRI displayed a mass lesion close to the posterior horn of the right lateral ventricle with low T1-signal intensity and high T2-signal intensity. Peritumoral edema was markedly presented and showed lower FA (0.08-0.22) compared to the contralateral whiter matter (0.40). Fibers displayed interruption distally to the right CST (fig. ) and did not significantly improve using an FA cut-off value of 0.10 for fiber-tracking. The mass was confirmed to be a metastatic tumor from a renal cell carcinoma of the right kidney after histopathological findings.