High Resolution Multi-Echo FLASH MRI of Fixated Human Brain with Combined Magnetization Transfer (MT) & T2* Weighting

Gunther Helms¹, Katrin Brunnquell¹, Arne Wrede², Walter J. Schulz-Schaeffer², Peter Dechent¹

A method for 3D gradient echo MRI of fixated human brains at 0.5 mm isotropic resolution is presented. Averaging the signals of 8 alternating echoes at TE = 2.46 to 19.68 ms increases the SNR and, by mild T2*-weighting, imposes a sensitivity to vessels and micro-bleedings. Magnetization transfer increases the contrast between gray and white matter. Measurement time is 35 min with an 8-channel receive array, 140 mins with a knee coil. Susceptibility effects are reduced by a bandwidth of 500 Hz/pixel. Structural details of fronto-basal and deep brain nuclei are visualized, while cortical substructures are at the resolution limit.