Department of Medical Physics, Uppsala University Hospital, Uppsala, Sweden.
Department of Radiology, Uppsala University Hospital, Uppsala, Sweden.
J Magn Reson Imaging. 2018 Feb;47(2):410-417. doi: 10.1002/jmri.25734. Epub 2017 Apr 17.
To evaluate the feasibility of an expiration multiple breath-hold H-MRS technique to measure glycogen (Glycg), choline-containing compounds (CCC), and lipid relaxation times T , T , and their concentrations in normal human liver.
Thirty healthy volunteers were recruited. Experiments were performed at 3T. Multiple expiration breath-hold single-voxel point-resolved spectroscopy (PRESS) technique was used for localization. Water-suppressed spectra were used for the estimation of Glycg, CCC, lipid methylene (CH ) relaxation times and concentrations. Residual water lines were removed by the Hankel Lanczos singular value decomposition filter. After phase correction and frequency alignment, spectra were averaged and processed by LCModel. Summed signals of Glycg resonances H2H4', H3, and H5 between 3.6 and 4 ppm were used to estimate their apparent relaxation times and concentration. Glycg, CCC, and lipid content were estimated from relaxation corrected spectral intensity ratios to unsuppressed water line.
Relaxation times were measured for liver Glycg (T , 892 ± 126 msec; T , 13 ± 4 msec), CCC (T , 842 ± 75 msec; T , 50 ± 5 msec), lipid (CH ) (T , 402 ± 19 msec; T , 52 ± 3 msec), and water (T , 990 ± 89 msec; T , 30 ± 2 msec). Mean CCC and lipid concentrations of healthy liver were 7.8 ± 1.3 mM and 15.8 ± 23.6 mM, respectively. Glycg content was found lower in the morning (48 ± 21 mM) compared to the afternoon (145 ± 50 mM).
Multiple breath-hold H-MRS together with dedicated postprocessing is a feasible technique for the quantification of liver Glycg, CCC, and lipid relaxation times and concentrations.
1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:410-417.
评估多次呼气暂停 H-MRS 技术测量正常人肝糖原（Glycg）、含胆碱化合物（CCC）和脂质弛豫时间 T 1 、T 2 及其浓度的可行性。
招募 30 名健康志愿者。在 3T 进行实验。采用多次呼气暂停单容积点分辨波谱（PRESS）技术进行定位。水抑制谱用于估计 Glycg、CCC、脂质亚甲基（CH 2 ）弛豫时间和浓度。通过汉克尔 Lanczos 奇异值分解滤波器去除残留水线。相位校正和频率对齐后，对光谱进行平均处理，并由 LCModel 进行处理。3.6 到 4ppm 之间 Glycg 共振 H2H4'、H3 和 H5 的总和信号用于估计其表观弛豫时间和浓度。从弛豫校正后的光谱强度比到未抑制的水线估计 Glycg、CCC 和脂质含量。
测量了肝 Glycg（T 1 ，892±126msec；T 2 ，13±4msec）、CCC（T 1 ，842±75msec；T 2 ，50±5msec）、脂质（CH 2 ）（T 1 ，402±19msec；T 2 ，52±3msec）和水（T 1 ，990±89msec；T 2 ，30±2msec）的弛豫时间。健康肝脏的平均 CCC 和脂质浓度分别为 7.8±1.3mM 和 15.8±23.6mM。上午（48±21mM）的 Glycg 含量低于下午（145±50mM）。
多次呼气暂停 H-MRS 与专用后处理相结合是一种可行的技术，可用于定量测量肝 Glycg、CCC 和脂质弛豫时间和浓度。
1 技术功效：第 2 阶段 J. Magn. Reson. Imaging 2018；47：410-417。
