Fast multi-parametric imaging in abdomen by B1+corrected dual-flip angle sequence with interleaved echo acquisition
Fast multi-parametric imaging in abdomen by B1+corrected dual-flip angle sequence with interleaved echo acquisition
复制标题
通过 B1 校正双翻转角度序列和交错回波采集进行腹部快速多参数成像
DOI：
10.1002/mrm.29127
复制
发表时间：
2021-12-10
影响因子：
3.3
通讯作者：
Zou, Chao
中科院分区：
文献类型：
--
作者：
Peng, Hao;Cheng, Chuanli;Zou, Chao
目的在单次宽度保持内实现腹部T-1、（w）/质子密度脂肪分数（PDFF）/R2* 的同步标测，并采用最新测量方法验证其准确性。理论与方法采用优化的多回波梯度回波（GRE）序列双翻转角采集，实现水T-1（T-1，（w））/PDFF/R2* 的同步定量。针对油水分离问题，提出了一种基于T-1差分的油水模糊度求解方法（SORT）。该方法基于以下发现：与真实解相比，脂肪-水分离问题的错误（或混叠）解由于脂肪和水之间的T-1差异而显示出对所应用的翻转角的额外依赖性。应用B1+测量序列校正T-1，（w）弛豫法的B1+不均匀性。采用2D并行成像，以实现腹部单次屏气内的采集。结果该方法的多参数定量结果与参考方法在体模实验中的结果一致（PDFF定量：R-2 = 0.993，平均误差0.73%; T-1，（w）定量：R-2 = 0.999，平均误差4.3%; R2* 定量：R-2 = 0.949，平均误差4.07 s（-1））。对于志愿者研究，实现了稳健的脂肪-水分离，没有明显的脂肪-水交换。基于精确的脂肪-水分离，在单次屏气内实现了全肝的T-1，（w）/PDFF/R2* 的同时定量。结论该方法可在单次屏气内准确定量全肝的T-1，（w）/PDFF/R2*。该技术可作为肝脏脂肪变性患者疾病管理的定量工具。
Purpose To achieve simultaneous T-1,(w)/proton density fat fraction (PDFF)/R2* mapping in abdomen within a single breadth-hold, and validate the accuracy using state-of-art measurement. Theory and Methods An optimized multiple echo gradient echo (GRE) sequence with dual flip-angle acquisition was used to realize simultaneous water T-1 (T-1,(w))/PDFF/R2* quantification. A new method, referred to as "solving the fat-water ambiguity based on their T-1 difference" (SORT), was proposed to address the fat-water separation problem. This method was based on the finding that compared to the true solution, the wrong (or aliased) solution to fat-water separation problem showed extra dependency on the applied flip angle due to the T-1 difference between fat and water. The B1+ measurement sequence was applied to correct the B1+ inhomogeneity for T-1,(w) relaxometry. The 2D parallel imaging was incorporated to enable the acquisition within a single breath-hold in abdomen. Results The multi-parametric quantification results of the proposed method were consistent with the results of reference methods in phantom experiments (PDFF quantification: R-2 = 0.993, mean error 0.73%; T-1,(w) quantification: R-2 = 0.999, mean error 4.3%; R2* quantification: R-2 = 0.949, mean error 4.07 s(-1)). For volunteer studies, robust fat-water separation was achieved without evident fat-water swaps. Based on the accurate fat-water separation, simultaneous T-1,(w)/PDFF/R2* quantification was realized for whole liver within a single breath-hold. Conclusion The proposed method accurately quantified T-1,(w)/PDFF/R2* for the whole liver within a single breath-hold. This technique serves as a quantitative tool for disease management in patients with hepatic steatosis.