Simultaneously Neuromelanin-sensitive Imaging and Quantitative Susceptibility Mapping in the Whole Brain

Abstract

Three-dimensional (3D) gradient recalled echo (GRE) sequence with magnetization transfer (MT) can simultaneously image neuromelanin and magnetic susceptibility. However, the sequence requires long duration of MT saturation pulse and the effect of MT pulse on susceptibility values remains unclear. Therefore, this paper aims to shorten the MT pulse duration and evaluate the effect of MT pulse on susceptibility value. Results showed that 3D GRE sequence with 5 ms of MT pulse provided a saturation effect no less than that of 8 ms, 10 ms and 12 ms in highlighting neuromelanin, and yielded susceptibility values in the deep gray matter nuclei similar to sequence without MT pulse. In conclusion, short MT pulse provides a practical means to simultaneously image the neuromelanin and magnetic susceptibility.

Keywords

• neuromelanin-sensitive magnetic resonance imaging (nm-mri)
• magnetization transfer (mt)
• quantitative susceptibility mapping (qsm)
• deep gray matter nuclei