Application of refocused steady-state free-precession methods at 1.5 and 3 T to in vivo high-resolution MRI of trabecular bone: Simulations and experiments
Application of refocused steady-state free-precession methods at 1.5 and 3 T to in vivo high-resolution MRI of trabecular bone: Simulations and experiments
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DOI：
10.1002/jmri.20348
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发表时间：
2005-06-01
影响因子：
4.4
通讯作者：
Majumdar, S
中科院分区：
文献类型：
--
作者：
Banerjee, S;Han, ET;Majumdar, S
用途：为了评估潜力的完全平衡的稳态自由旋进（SSFP）序列在体内高分辨率（HR）MRI的骨小梁的场强为1.5和3 T的模拟和实验methods.Materials和方法：使用模拟研究，重新聚焦的SSFP采集进行了优化，我们的成像目的，重点是信噪比（SNR）和SNR效率。使用骨小梁和骨髓的静磁模型估计骨小梁中的信号行为。8名正常志愿者在GE Signa扫描仪上以1.5 T和3 T对股骨近端、跟骨和胫骨远端进行成像，使用优化的单次采集SSFP序列（三维FIESTA）和优化的多次采集SSFP序列（三维FIESTA-c）。图像也获得了一个快速梯度回波（FGRE）序列的SNR性能SSFP methods.Results的评价：重新聚焦SSFP图像优于FGRE收购在两个领域的强度在SNR和SNR效率。在3 T时，在FIESTA和FGRE图像中可见敏感性效应，在FIESTA-c图像中大大降低。结论：单次采集SSFP（1.5T）和多次采集SSFP（3 T）在骨小梁HR-MRI中具有很大的潜力。(c)2005 Wiley-Liss，Inc.
Purpose: To evaluate the potential of fully-balanced steady-state free-precession (SSFP) sequences in in vivo high-resolution (HR) MRI of trabecular bone at field strengths of 1.5 and 3 T by simulation and experimental methods.Materials and Methods: Using simulation studies, refocused SSFP acquisition was optimized for our imaging purposes with a focus on signal-to-noise ratio (SNR) and SNR efficiency. The signal behavior in trabecular bone was estimated using a magnetostatic model of the trabecular bone and marrow. Eight normal volunteers were imaged at the proximal femur, calcaneus, and the distal tibia on a GE Signa scanner at 1.5 and at 3 T with an optimized single-acquisition SSFP sequence (three-dimensional FIESTA) and an optimized multiple-acquisition SSFP sequence (three-dimensional FIESTA-c). Images were also acquired with a fast gradient echo (FGRE) sequence for evaluation of the SNR performance of SSFP methods.Results: Refocused SSFP images outperformed FGRE acquisitions in both SNR and SNR efficiency at both field strengths. At 3 T, susceptibility effects were visible in FIESTA and FGRE images and much reduced in FIESTA-c images. The magnitude of SNR boost at 3 T was closely predicted by simulations.Conclusion: Single-acquisition SSFP (at 1.5 T) and multiple-acquisition SSFP (at 3 T) hold great potential for HR-MRI of trabecular bone. (c) 2005 Wiley-Liss, Inc.