Fiber density index, fractional anisotropy, adc and clinical motor findings in the white matter of patients with glioblastoma.

Whether fractional anisotropy (FA), apparent diffusion coefficient (ADC), and fiber density index (FDi) values differ in the white matter close to glioblastomas of both symptomatic and asymptomatic patients was investigated. Twenty patients with glioblastomas underwent magnetic resonance imaging study. The FDi, FA and ADC values were calculated in areas of white matter in close proximity to the tumor (perWM) and encompassing fibers of cortico-spinal tract and in the contralateral normal-appearing white matter (nWM). The clinical compromise of the cortico-spinal tract was graded using Brunnstrom's criteria. FA and FDi were significantly decreased and ADC increased in perWM compared with the contralateral. Mean FDi, FA, and ADC values comparing perWM and nWM in symptomatic patients showed similar differences. Comparing the perWM of symptomatic and asymptomatic patients, mean FDi and ADC values were lower in symptomatic patients than in asymptomatic ones. A positive correlation was found between the clinical score (CS) and, separately, FDi, FA and ADC per WM values. In a multiple stepwise regression among the same factors, only the ADC of perWM values showed a positive correlation with the CS. An increased ADC plays a major role in reducing the number of fibers (reduced FDi) in symptomatic patients.