Fig. 7.

Performance differences in differential tractography due to different b-values. (a) Diffusion-weighted images of a patient at b-values of 0, 3000, and 7000 s/mm². Signals at high b-values are sensitive to restricted diffusion but have a lower signal-to-noise ratio. Thus most clinical scans only acquire b-value lower than 3000 s/mm². (b) Differential tractography using reduced b-values between 0 and 3,000 s/mm² shows 54% fewer findings than those from the full dataset using b-values between 0 and 7,000 s/mm². Although the reduced b-value dataset also shows a grossly similar result, its FDR is substantially higher (FDR=0.32) and thus not as reliable as the full dataset that includes high b-value data. The result indicates the important role of high b-value acquisition in detecting early neuronal injury.