Real-time accelerated interactive MRI with adaptive TSENSE and UNFOLD
Real-time accelerated interactive MRI with adaptive TSENSE and UNFOLD
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DOI：
10.1002/mrm.10504
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发表时间：
2003-08-01
影响因子：
3.3
通讯作者：
McVeigh, ER
中科院分区：
文献类型：
--
作者：
Guttman, MA;Kellman, P;McVeigh, ER
使用时间自适应灵敏度编码 (TSENSE) 减少视场 (FOV) 加速或通过使用时间维度对重叠进行傅里叶编码 (UNFOLD) 消除混叠可以改善实时 MRI 中运动的描绘。然而，需要增加计算资源来维持图像重建和显示的高帧速率和低延迟。高性能软件系统已被实施，用于通过交互式在线显示执行实时 MRI 的 TSENSE 和 UNFOLD 重建。图像显示在扫描仪室中以研究图像引导程序。显示了使用稳态自由进动 (SSFP) 序列的正常志愿者和动物心脏介入实验的示例。为了保持介入手术足够的图像质量，在加速因子为 2 且体素尺寸为 1.8 x 3.5 x 8 mm 后，成像速率被限制为每秒 7 帧。初步经验表明，TSENSE 和 UNFOLD 都可以改善实时成像中空间和时间分辨率之间的折衷，并且可以在交互式成像中发挥良好作用。 UNFOLD 对接收线圈没有额外的限制，因此比 SENSE 方法更灵活；然而，时间图像滤波会模糊运动并降低有效加速度。提出了一些方法来克服在交互式成像中使用 TSENSE 带来的挑战。更改成像平面后，TSENSE 可能会暂时禁用，以避免灵敏度系数适应时出现瞬态伪影。对于表面线圈和介入线圈组合的成像，提出了一种混合重建方法，其中 UNFOLD 用于介入线圈，并且带有或不带有 UNFOLD 的 TSENSE 用于表面线圈。 2003 年出版 Wiley-Liss, Inc.
Reduced field-of-view (FOV) acceleration using time-adaptive sensitivity encoding (TSENSE) or unaliasing by Fourier encoding the overlaps using the temporal dimension (UNFOLD) can improve the depiction of motion in real-time MRI. However, increased computational resources are required to maintain a high frame rate and low latency in image reconstruction and display. A high-performance software system has been implemented to perform TSENSE and UNFOLD reconstructions for real-time MRI with interactive, on-line display. Images were displayed in the scanner room to investigate image-guided procedures. Examples are shown for normal volunteers and cardiac interventional experiments in animals using a steady-state free precession (SSFP) sequence. In order to maintain adequate image quality for interventional procedures, the imaging rate was limited to seven frames per second after an acceleration factor of 2 with a voxel size of 1.8 x 3.5 x 8 mm. Initial experiences suggest that TSENSE and UNFOLD can each improve the compromise between spatial and temporal resolution in real-time imaging, and can function well in interactive imaging. UNFOLD places no additional constraints on receiver coils, and is therefore more flexible than SENSE methods; however, the temporal image filtering can blur motion and reduce the effective acceleration. Methods are proposed to overcome the challenges presented by the use of TSENSE in interactive imaging. TSENSE may be temporarily disabled after changing the imaging plane to avoid transient artifacts as the sensitivity coefficients adapt. For imaging with a combination of surface and interventional coils, a hybrid reconstruction approach is proposed whereby UNFOLD is used for the interventional coils, and TSENSE with or without UNFOLD is used for the surface coils. Published 2003 Wiley-Liss, Inc.