Purpose. This study aims to investigate the feasibility of different acquisition methods for time-resolved magnetic resonance fingerprinting (TR-MRF) in computer simulation. Methods. An extended cardiac-torso (XCAT) phantom is used to generate abdominal T1, T2, and proton density maps for MRF simulation. The simulated MRF technique consists of an IR-FISP MRF sequence with spiral trajectory acquisition. MRF maps were simulated with different numbers of repetitions from 1 to 15. Three different methods were used to generate TR-MRF maps: (1) continuous acquisition without delay between MRF repetitions; (2) continuous acquisition with 5 s delay between MRF repetitions; (3) triggered acquisition with variable delay between MRF repetitions to allow the next acquisition to start at different respiration phase. After the generation of TR-MRF maps, the image quality indexes including the absolute T1 and T2 values, signal-to-noise-ratio (SNR), tumor-to-liver contrast-to-noise ratio, error in the amplitude of diaphragm motion and tumor volume error were used to evaluate the reconstructed parameter maps. Three volunteers were recruited to test the feasibility of the selected acquisition method. Results. Dynamic MR parametric maps using three different acquisition methods were estimated. The overall and liver T1 value error, liver SNR in T1 and T2 maps, and tumor SNR from T1 maps from triggered method is statistically significantly better than the other two methods (p-value<0.05). The other image quality indexes have no significant difference between the triggered method and the other two continuous acquisition methods. All image quality indexes exhibit no significant difference between the acquisition methods with 0 s and 5 s delay. The triggered method was successfully performed in three healthy volunteers. Conclusion. TR-MRF technique was investigated using three different acquisition methods in computer simulation where the triggered method showed better performance than the other two methods. The triggered method has been tested successfully in healthy volunteers.

目的。本研究旨在研究计算机模拟中时间分辨磁共振指纹 (TR-MRF) 的不同采集方法的可行性。方法。扩展心脏躯干 (XCAT) 体模用于生成用于 MRF 模拟的腹部 T1、T2 和质子密度图。模拟 MRF 技术由具有螺旋轨迹采集的 IR-FISP MRF 序列组成。MRF 图用从 1 到 15 次不同的重复次数进行模拟。使用三种不同的方法来生成 TR-MRF 图：(1) 在 MRF 重复之间无延迟的连续采集；(2) 在 MRF 重复之间延迟 5 秒的连续采集；(3) 在 MRF 重复之间具有可变延迟的触发采集，以允许下一次采集在不同的呼吸阶段开始。生成TR-MRF图后，图像质量指标包括绝对T1和T2值、信噪比（SNR）、肿瘤与肝脏的对比噪声比、横膈膜运动幅度误差和肿瘤体积误差用于评估重建的参数图。招募了三名志愿者来测试所选采集方法的可行性。结果。使用三种不同的采集方法估计动态 MR 参数图。总体和肝脏 T1 值误差、T1 和 T2 图中的肝脏 SNR 以及触发方法的 T1 图中的肿瘤 SNR 在统计上显着优于其他两种方法（p值 <0.05）。其他图像质量指标与触发方式和其他两种连续采集方式无显着差异。所有图像质量指标在具有 0 s 和 5 s 延迟的采集方法之间没有显着差异。触发方法在三名健康志愿者中成功执行。结论。在计算机模拟中使用三种不同的采集方法研究了 TR-MRF 技术，其中触发方法显示出比其他两种方法更好的性能。触发方法已在健康志愿者中成功测试。