PERFUSION MAPPING WITH MULTIECHO MULTISHOT PARALLEL IMAGING EPI

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 基于动态磁化率对比(DSC)的灌注加权成像(PWI)可以直观地显示脑血管血流动力学。因此，确定急性卒中患者的危险组织可能是一项重要的资产。当与弥散加权成像(DWI)一起使用时，它可以帮助对可能从静脉注射tPA治疗或机械血栓切除术中受益的患者进行分类。在DSC成像中，外源性顺磁示踪剂(例如，Gd-DTPA或Dy-DTPA)被快速注入静脉系统，并通过脑血管床中与浓度相关的T2*变化来跟踪其通过。 平面回波成像(EPI)是动态磁化率-对比度(DSC)灌注磁共振成像的标准技术。然而，EPI存在着众所周知的几何失真，这种失真可以通过增加k空间相速度来减小。此外，DSC中使用的长回波时间(TES)导致动脉输入信号的信号饱和，从而导致血流动力学信息的严重量化误差。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Dynamic susceptibility contrast (DSC)-based perfusion-weighted imaging (PWI) can visualize cerebrovascular hemodynamics. Therefore, it may be an important asset to determine tissue-at-risk in acute stroke patients. When used with diffusion-weighted imaging (DWI), it can help to triage patients who would potentially benefit from IV tPA treatment or mechanical thrombectomy. In DSC imaging, an exogenous paramagnetic tracer (e.g., Gd-DTPA or Dy-DTPA) is rapidly injected into the venous system and its passage is tracked through concentration-related T2* changes in the cerebral vascular bed. Echo-planar imaging (EPI) is the standard technique for dynamic susceptibility-contrast (DSC) perfusion MRI. However, EPI suffers from well-known geometric distortions, which can be reduced by increasing the k-space phase velocity. Moreover, the long echo times (TEs) used in DSC lead to signal saturation of the arterial input signal, and hence to severe quantitation errors in the hemodynamic information.