ARTIFACT REDUCTION IN ECHO PLANAR IMAGING W/ PHASE ENCODED REFERENCE SCAN

回波平面成像(EPI)对磁场很敏感 导致信号丢失和几何失真的不均匀性 这个形象。磁感应产生的磁场不均匀 在人体中遇到的易感性差异会增加 随着磁场强度的增加。因此，这是一个挑战 在强磁场上实现高分辨率EPI技术 系统。此外，在EPI图像中，每条k空间线具有不同的 如果存在流，则在相位编码方向上进行去相，导致 相位编码方向上的伪影。在上一次拨款期间， 我们开发了一种新的用于EPI的相位编码参考方案 证明了新的参考方案实际上消除了N/2 尽管有很强的场不均匀性，但在高场中仍存在鬼影。 EPI AS中Bo不均匀性可能引起的图像失真 以及其他超快成像序列也在 去年使用了一种新的技术来纠正这种图像退化。

Echo-planar imaging (EPI) is sensitive to magnetic field inhomogeneities which lead to signal loss and geometric distortions of the image. The magnetic field inhomogeneities induced due to susceptibility differences, as encountered in the human body, increase with the magnetic field strength. Thus, it is a challenge to implement high resolution EPI techniques on high magnetic field systems. Furthermore, in EPI images, each k-space line has different dephasing in the phase-encoding direction if flow is present, causing artifacts in the phase-encoding direction. In the last grant period, we developed a new phase-encoded referencing scheme for EPI and demonstrated that the new referencing scheme virtually eliminates N/2 ghosts despite the strong field inhomogeneity present at high fields. The image distortion that may arise from Bo inhomogeneity in EPI as well as other ultrafast imaging sequences was also addressed in the last year with a new technique for correction such image degradation.