Hansen Esben Szocska Søvsø, Kim Sun, Miller Jack J, Geferath Marcus, Morrell Glen, Laustsen Christoffer
MR Research Centre, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford; Danish Diabetes Academy, Odense, Denmark.
Department of Neurology & Neurological Sciences, Stanford Hospital & Clinics, Palo Alto, California.
Tomography. 2016 Jun;2(2):117-124. doi: 10.18383/j.tom.2016.00154.
The fast Padé transform (FPT) is a method of spectral analysis that can be used to reconstruct nuclear magnetic resonance spectra from truncated free induction decay signals with superior robustness and spectral resolution compared with conventional Fourier analysis. The aim of this study is to show the utility of FPT in reducing of the scan time required for hyperpolarized C chemical shift imaging (CSI) without sacrificing the ability to resolve a full spectrum. Simulations, phantom, and in vivo hyperpolarized [1-C] pyruvate CSI data were processed with FPT and compared with conventional analysis methods. FPT shows improved stability and spectral resolution on truncated data compared with the fast Fourier transform and shows results that are comparable to those of the model-based fitting methods, enabling a reduction in the needed acquisition time in C CSI experiments. Using FPT can reduce the readout length in the spectral dimension by 2-6 times in C CSI compared with conventional Fourier analysis without sacrificing the spectral resolution. This increased speed is crucial for C CSI because T1 relaxation considerably limits the available scan time. In addition, FPT can also yield direct quantification of metabolite concentration without the additional peak analysis required in conventional Fourier analysis.
快速帕德变换（FPT）是一种光谱分析方法，与传统傅里叶分析相比，它可用于从截断的自由感应衰减信号中重建核磁共振谱，具有更高的稳健性和光谱分辨率。本研究的目的是展示FPT在不牺牲全谱分辨能力的情况下，用于减少超极化碳化学位移成像（CSI）所需扫描时间的效用。用FPT处理模拟、体模和体内超极化[1-C]丙酮酸CSI数据，并与传统分析方法进行比较。与快速傅里叶变换相比，FPT在截断数据上显示出更高的稳定性和光谱分辨率，其结果与基于模型的拟合方法相当，从而能够减少碳CSI实验中所需的采集时间。与传统傅里叶分析相比，在碳CSI中使用FPT可在不牺牲光谱分辨率的情况下，将光谱维度的读出长度减少2至6倍。这种速度提升对于碳CSI至关重要，因为T1弛豫会极大地限制可用扫描时间。此外，FPT还可直接对代谢物浓度进行定量，而无需传统傅里叶分析中额外的峰分析。
