To use MR with diffusion tensor imaging (DTI) and conventional and high b value to assess diffusion changes in normal-appearing white matter (NAWM) in patients with unilateral, severe stenosis, or occlusion of the middle cerebral artery (MCA).Materials and Methods
In total, 28 patients with NAWM and unilateral, severe stenosis, or occlusion of the MCA underwent DTI with b values 1000 and 2200 s/mm2 at 3.0T MR. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), radial diffusivity (eigenvalues λ1, λ2), and axial diffusivity (eigenvalue λ3) were measured for the ipsilateral and contralateral corona radiata.Results
Mean FA was significantly lower for the ipsilateral than contralateral corona radiata with high b value, 2200 s/mm2, and ipsilateral corona radiata with conventional low b value, 1000 s/mm2 (all P < 0.01). Mean ADC, λ1, λ2, and λ3 were significantly higher for the ipsilateral than contralateral corona radiata with high b value (all P < 0.05) but not for ipsilateral than contralateral corona radiata with low b value (P > 0.05).Conclusion
DTI with a high b value detects diffusion changes in NAWM in patients with unilateral, severe stenosis, or occlusion of the MCA not seen with conventional b value or conventional MRI contrasts. J. Magn. Reson. Imaging 2013;38:650–654. © 2012 Wiley Periodicals, Inc.