定量磁化率成像重建方法及其应用

Quantitative Susceptibility Mapping

磁共振成像(MRI)中,相位图像包含丰富的组织磁化率变化信息,获取相位图像不需要额外的扫描时间.组织中的顺磁性物质会影响组织磁化率差异,从而导致局部磁场不均匀.对组织内顺磁性物质的定量有利于许多脑血管疾病和神经系统疾病的诊断,但利用局部相位信息重建组织磁化率分布是一个不适定逆问题,目前仍然有许多问题亟待解决.该文着重介绍定量磁化率成像(QSM)的原理、重建方法及其在MRI中的应用.

Phase images of magnetic resonance imaging （MRI）＇contain abundant information about local susceptibility changes among different types of tissues, and getting phase images requires no additional scan time. The diagnosis of cerebrovascular diseases and nervous system diseases may benefit from the quantification of paramagnetic substances in tissues. Quantitative susceptibility mapping （QSM）, which uses the local phase information, has become a hot topic in basic and clinical studies, l^aramagnetic substances in tissues cause local susceptibility changes and lead to local inhomogeneous magnetic field. However, the reconstruction of susceptibility distribution from induced magnetic field is an ill-posed inverse problem, and there are still many problems to be solved at present. This article focuses on the theory of QSM, reconstruction methods and its applications in MRI.