磁共振指纹技术:通过MRI获得标准化影像生物标志物的新方法

Magnetic Resonance Fingerprinting——a promising new approach to obtain standardized imaging biomarkers from MRI

目前常规MRI检查依靠采集对比"加权"定性图像评价有多种组织特性(磁性)的混合物。最近引入的一种新的方法——磁共振指纹(MR Fingerprinting,MRF),以一种全新的方法对数据进行采集、后处理和实现可视化。MRF使用一种伪随机采集(a pseudo randomized acquisition)方法取代过去为获得个体感兴趣的参数特征,而使用重复系列数据采集方法,这种方法从不同组织中产生信号,并使之具有唯一的信号演变或"指纹",即同时获得所研究的不同物质特性的功能。数据采集后的处理过程涉及一个模式识别算法,将"指纹"与预测信号演变的预定义资料库(a predefined dictionary)匹配。然后,这些指纹被转换成兴趣区的磁性参数定量图。理论上,磁共振指纹(MRF)可以应用于大部分的传统MRI定性方法,并取代它们获取真正定量的组织参数。因此,MRF有望比传统MRI更准确和更具可重复性,并促进多中心研究,在影像诊断时显著减少阅片者的偏倚。

Current routine MRI examinations rely on the acquisition of qualitative images that have a contrast ＂weighted＂ for a mixture of（magnetic） tissue properties. Recently, a novel approach was introduced, namely MR Fingerprinting（MRF） with a completely different approach to data acquisition, postprocessing and visualization. Instead of using a repeated, serial acquisition of data for the characterization of individual parameters of interest, MRF uses a pseudo randomized acquisition that causes the signals from different tissues to have a unique signal evolution or ＇fingerprint＇ that is simultaneously a function of the multiple material properties under investigation. The processing after acquisition involves a pattern recognition algorithm to match the fingerprints to a predefined dictionary of predicted signal evolutions. These can then be translated into quantitative maps of the magnetic parameters of interest.MR Fingerprinting（MRF） is a technique that could theoretically be applied to most traditional qualitative MRI methods and replaces them with acquisition of truly quantitative tissue measures. MRF is, thereby, expected to be much more accurate and reproducible than traditional MRI and should improve multi-center studies and significantly reduce reader bias when diagnostic imaging is performed.