Han SoHyun, Cho HyungJoon
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
J Magn Reson Imaging. 2016 Jul;44(1):138-47. doi: 10.1002/jmri.25136. Epub 2015 Dec 29.
To enhance the temporal resolution of calibration-free dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) by implementing compressed sensing assisted turbo spin echo (CS-TSE) acquisition.
The dynamic sparse sampling variables including acceleration factor, randomized phase encoding distributions, and reconstruction constraints were retrospectively optimized by minimizing the difference from fully sampled dynamic TSE at 7T. The degree of contrast enhancement and the calibration-free quantification of gadolinium (Gd) concentration were evaluated among fast low-angle shot (FLASH), TSE, and CS-TSE acquisitions with multiple phantoms (0.1-6 mM). The kidney-feeding in vivo arterial input function (AIF) was measured at multiple administration doses (0.1-0.3 mmol/kg) to evaluate the benefit of CS-TSE for quantifying rapidly changing high Gd concentrations in C57BL/6 mice (n = 22).
In phantom studies, both calibration-free and calibrated conversions estimated equivalent Gd concentrations for CS-TSE (scatterplot slope = 0.9801, r(2) = 0.9998, P < 0.001). In in vivo studies, 4-fold higher temporal resolution (0.96 sec) of CS-TSE over the corresponding TSE enabled robust measurement of AIF first-pass peak and resulting peak enhancement with CS-TSE were observed, with 1.1439- and 2.1258-fold times higher than those with TSE and FLASH acquisitions, respectively, at the 0.1 mmol/kg dose. Calibration-free estimates of AIF peak concentration with CS-TSE were in good agreement with the calibrated approach at multiple administration doses (scatterplot slope = 0.7800, r(2) = 0.8014, P < 0.001).
Temporal resolution-improved CS-TSE provides practical subsecond (0.96s) calibration-free dynamic MR quantification of high Gd concentration. J. Magn. Reson. Imaging 2016;44:138-147.
通过实施压缩感知辅助的涡轮自旋回波（CS-TSE）采集来提高无校准动态对比增强磁共振成像（DCE-MRI）的时间分辨率。
通过最小化与7T下全采样动态TSE的差异，对包括加速因子、随机相位编码分布和重建约束在内的动态稀疏采样变量进行回顾性优化。在使用多个体模（0.1 - 6 mM）的快速低角度激发（FLASH）、TSE和CS-TSE采集中，评估对比增强程度和钆（Gd）浓度的无校准定量。在多个给药剂量（0.1 - 0.3 mmol/kg）下测量C57BL/6小鼠（n = 22）的肾脏供血体内动脉输入函数（AIF），以评估CS-TSE在量化快速变化的高Gd浓度方面的优势。
在体模研究中，无校准和校准后的转换都估计CS-TSE的Gd浓度相当（散点图斜率 = 0.9801，r² = 0.9998，P < 0.001）。在体内研究中，CS-TSE的时间分辨率比相应的TSE高4倍（0.96秒），能够稳健地测量AIF首过峰值，并且在0.1 mmol/kg剂量下，CS-TSE产生的峰值增强分别比TSE和FLASH采集高1.1439倍和2.1258倍。CS-TSE对AIF峰值浓度的无校准估计与多个给药剂量下的校准方法高度一致（散点图斜率 = 0.7800，r² = 0.8*014，P < 0.001）。
时间分辨率提高的CS-TSE提供了实用的亚秒级（0.96秒）无校准动态MR高Gd浓度定量。《磁共振成像杂志》2016年；44:138 - 147。
