Enhanced gray and white matter contrast of phase susceptibility-weighted images in ultra-high-field magnetic resonance imaging

Purpose: To evaluate if magnetic susceptibility sensitive phase postprocessed images can be used to enhance the inherent brain/gray white matter contrast in gradient echo (GE) images at 8-Tesla (T) magnetic resonance (MR). Materials and Methods: Phase and magnitude images of high-resolution GE MR 8-T images were created. Comparisons were made between the magnitude; the product of the magnitude and phase, and pure phase images. Results: The pure phase images significantly improved the contrast between the gray and white matter structures. In general, the higher the iron content or subvoxel field inhomogeneities, the higher was the contrast, and the greater were the resultant phase shifts. The phase images best demonstrated anatomy that was not apparent on the standard magnitude images. Conclusion: Phase imaging can significantly improve the demonstration of the internal anatomical brain structures over standard magnitude GE imaging techniques at high field.