基于双对比机制和三维容积采集的磁共振指纹式成像方法的研究

A novel simultaneous multiple quantitative MRI method called MR fingerprinting (MRF) was published on Nature in 2013. European Society of Radiology has stated that MRF is a promising new approach to replace most traditional qualitative MRI methods and obtain standardized imaging biomarkers with high accuracy and reproducibility from MRI. Even though MRF has been improved in various aspects since then, several main obstacles remain that still prevent MRF from wide clinical adoption. The disadvantages include the less accurate T2 quantification, and low image resolution. To improve upon all these, we propose two dual-contrast MRF schemes, one additionally use 0 0 phase cycling in bSSFP-based MRF to remove banding artifact and the other introduce an additional Echo-like signal into the FISP-based MRF to improve T2 contrast; we also propose 3D volume MRF schemes to improve intrinsic SNR and to increase image resolution; finally, we propose to combine the dual-contrast scheme and 3D volume acquisition to achieve accurate (mean error < 10%), high spatial resolution (1mm isotropic) and high efficient (whole brain acquisition < 10 min) MRF, which will greatly improve the feasibility for clinical diagnosis.

一种创新的多参数同时定量成像的磁共振指纹式成像（MRF）方法在13年的Nature杂志发表。欧洲放射学会声明MRF可用于替代包括T1、T2加权的大部分常规临床扫描并提供更准确的可重复的标准化的多参数生物指标。近几年来，MRF已经获得了多方面改进。然而，MRF还存在诸多不足，包括T2的定量准确性有待提升、图像的分辨率有待提高，这些不足限制了MRF向临床的推广。针对以上不足，本项目提出两类基于双对比机制的MRF，更充分地利用射频相位的可调控性和信号类型的可调控性，用于去除原MRF中的带状伪影以提高图像质量和提高对T2定量的敏感度与准确性；还提出基于三维容积的MRF用于提升信号内在的信噪比以用于图像分辨率的提升；两大方法的有机结合将极有可能实现准确的（平均误差小于10%）高分辨率的（1mm各项同性）快速的（全脑采集<10分钟）MRF，极大提升MRF实用性，以便更好的用于临床诊断。

一种创新的多参数同时定量成像的磁共振指纹式成像（MRF）方法在13年的Nature杂志发表。欧洲放射学会声明MRF可用于替代包括T1、T2加权的大部分常规临床扫描并提供更准确的可重复的标准化的多参数生物指标。近几年来，MRF已经获得了多方面改进。然而，MRF还存在诸多不足，包括T2的定量准确性有待提升、运动伪影和系统误差有待校正、图像的分辨率有待提高、临床应用有待验证等，这些不足限制了MRF向临床的推广。针对以上不足，本项目提出基于FISP和PSIF的双回波的MRF，用于提高对T2定量的敏感度与准确性；提出超短回波时间的MRF，用于同时测量短T2成分和长T2成分的组织参数；提出运动校正的MRF，提高MRF在实际应用中的鲁棒性；提出同时磁共振激发和接收场定量和校正的磁共振指纹式成像，通过编码系统误差并解码实现系统误差的校正；提出基于三维容积的MRF用于提升信号内在的信噪比以用于在较短采集时间的同时提升图像分辨率；以及将MRF用于提高颞叶癫痫病人的海马硬化检测的准确性。