Miloushev Vesselin Z, Di Gialleonardo Valentina, Salamanca-Cardona Lucia, Correa Fabian, Granlund Kristin L, Keshari Kayvan R
Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
J Magn Reson. 2017 Feb;275:120-126. doi: 10.1016/j.jmr.2016.12.009. Epub 2016 Dec 21.
The expected signal in echo-planar spectroscopic imaging experiments was explicitly modeled jointly in spatial and spectral dimensions. Using this as a basis, absorptive-mode type detection can be achieved by appropriate choice of spectral delays and post-processing techniques. We discuss the effects of gradient imperfections and demonstrate the implementation of this sequence at low field (1.05T), with application to hyperpolarized [1-C] pyruvate imaging of the mouse brain. The sequence achieves sufficient signal-to-noise to monitor the conversion of hyperpolarized [1-C] pyruvate to lactate in the mouse brain. Hyperpolarized pyruvate imaging of mouse brain metabolism using an absorptive-mode EPSI sequence can be applied to more sophisticated murine disease and treatment models. The simple modifications presented in this work, which permit absorptive-mode detection, are directly translatable to human clinical imaging and generate improved absorptive-mode spectra without the need for refocusing pulses.
在回波平面光谱成像实验中，预期信号在空间和光谱维度上进行了明确的联合建模。以此为基础，通过适当选择光谱延迟和后处理技术，可以实现吸收模式类型的检测。我们讨论了梯度缺陷的影响，并展示了该序列在低场（1.05T）下的实现，以及其在小鼠脑超极化[1-C]丙酮酸成像中的应用。该序列具有足够的信噪比，能够监测小鼠脑中超极化[1-C]丙酮酸向乳酸的转化。使用吸收模式EPSI序列对小鼠脑代谢进行超极化丙酮酸成像可应用于更复杂的小鼠疾病和治疗模型。本工作中提出的允许吸收模式检测的简单修改可直接转化为人体临床成像，并且无需重聚焦脉冲即可生成改进的吸收模式光谱。
