Magnetic susceptibility-weighted MR phase imaging of the human brain.

BACKGROUND AND PURPOSE MR gradient echo imaging is sensitive to the magnetic susceptibility of different tissue types. The purpose of this study was to investigate the diagnostic potential of MR phase imaging of the human brain. METHODS High-spatial-resolution, T2*-weighted, single-echo images were acquired in five volunteers and one patient with a brain tumor on a 1.5T system by applying a 3D, first-order, velocity-compensated gradient echo sequence by using a quadrature transmit-receive head coil. Phase images were reconstructed from the raw data and unwrapped by using a region-growing phase-unwrapping algorithm. Low-spatial-frequency components originating from static background susceptibility effects were removed by high-pass filtering. RESULTS Phase images showed excellent image contrast and revealed anatomic structures that were not visible on the corresponding magnitude images. CONCLUSION Improved processing of susceptibility-weighted MR phase images offers a new means of contrast for neuroimaging applications.