Characterizing the contrast of white matter and grey matter in high-resolution phase difference enhanced imaging of human brain at 3.0 T

The purpose of this study was to address the feasibility of characterizing the contrast both between and within grey matter and white matter using the phase difference enhanced (PADRE) technique. PADRE imaging was performed in 33 healthy volunteers. Vessel enhancement (VE), tissue enhancement (TE), and PADRE images were reconstructed from source images and were evaluated with regard to differentiation of grey-to-white matter interface, the stria of Gennari, and the two layers, internal sagittal stratum (ISS) and external sagittal stratum (ESS), of optic radiation. White matter regions showed decreased signal intensity compared to grey matter regions. Discrimination was sharper between white matter and cortical grey matter in TE images than in PADRE images, but was poorly displayed in VE images. The stria of Gennari was observed on all three image sets. Low-signal-intensity bands displayed in VE images representing the optic radiation were delineated as two layers of different signal intensities in TE and PADRE images. Statistically significant differences in phase shifts were found between frontal grey and white matter, as well as between ISS and ESS (p < 0.01). The PADRE technique is capable of identifying grey-to-white matter interface, the stria of Gennari, and ISS and ESS, with improved contrast in PADRE and TE images compared to VE images. (orig.)