Extrapolation-Based References Improve Motion and Eddy-Current Correction of High B-Value DWI Data: Application in Parkinson’s Disease Dementia
Fig 3
Comparison of image contrasts.
A: Acquired without diffusion encoding. B: Acquired using a high b-value. C: Extrapolated using the CHARMED model. D: Extrapolated using the proposed method with CSF correction. The two bottom rows show magnifications of anterior segments of the brain for two diffusion encoding directions. The yellow lines show the outline of the brain at a fixed position across all of the images. Note how the anterior rim of CSF is completely attenuated in the high b-value image (compare A and B). Both extrapolation methods yielded images with gross contrast similar to the acquired images. However, the CHARMED model introduced a shift in the outline of the brain for some encoding directions (compare outlines between bottom two rows in column C). For the proposed method, the outline of the brain did not vary substantially with encoding direction (column D).