Published in:
Open Access 01-08-2010 | Topic Article
Optimum b value for resolving crossing fibers: a study with standard clinical b value using 1.5-T MR
Published in: Neuroradiology | Issue 8/2010
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Introduction
We sought to investigate the optimum b value for resolving crossing fiber using high-angular resolution diffusion imaging (HARDI)-based multi-tensor tractography. The study tested the standard b values that are commonly used in the routine clinical setting.
Methods
Ten normal volunteers (five men and five women) with a mean age of 26.3 years (range, 22–32 years) were scanned using a 1.5-T clinical magnetic resonance unit. Single-shot echo-planar imaging was used for diffusion-weighted imaging with a diffusion-sensitizing gradient in 32 orientations. The b values of 700, 1,400, 2,100, and 2,800 s/m2 were used. Data postprocessing was performed using multi-tensor methods. The depiction of the optic nerves, optic tracts, and decussation of superior cerebellar peduncles were assessed.
Results
The depictions of the nerve fibers were independent of the b values tested.
Conclusion
The depiction of crossing fibers by HARDI-based multi-tensor tractography is not substantially influenced by b values ranging from 700 to 2,800 s/m2. Thus, the optimum b value within this range may be the lowest one considering the higher signal to noise ratio.