Investigations of the Origin of Phase Differences Seen with Ultrashort TE Imaging of Short T2 Meniscal Tissue
Investigations of the Origin of Phase Differences Seen with Ultrashort TE Imaging of Short T2 Meniscal Tissue
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DOI：
10.1002/mrm.23075
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发表时间：
2012-04-01
影响因子：
3.3
通讯作者：
Chiang, Jing-Tzyh Alan
中科院分区：
文献类型：
--
作者：
Carl, Michael;Chiang, Jing-Tzyh Alan
超短回波时间 MRI 需要标称回波时间低至几微秒的专用脉冲序列，以检测来自肌肉骨骼系统中经常遇到的短 T-2 组织的信号。通常，重建震级图像并且这些图像通常显示低组织对比度。尽管回波时间非常短，但半月板的超短回波时间相位图像却显示出惊人的高对比度。在本文中，我们使用布洛赫方程、模拟、模型实验和组织研究研究了这种对比的来源。结果表明，在有限射频脉冲和读出周期期间，超短回波时间序列中会发生相位演化，并且在半月板中观察到纤维组之间先前未识别的磁化率差异。 Magn Reson Med 67:991-1003, 2012。(c) 2011 Wiley periodicals, Inc.
Ultrashort echo time MRI requires specialized pulse sequences with nominal echo times as low as a few microseconds to detect signals from the short T-2 tissues frequently encountered in the musculoskeletal system. Usually, magnitude images are reconstructed and these often show low tissue contrast. Ultrashort echo time phase images of the meniscus show surprisingly high contrast despite their very short echo time. In this article, we investigated the source of this contrast using the Bloch equations, simulations, phantom experiments, and tissue studies. Phase evolution was shown to occur in ultrashort echo time sequences during the finite radiofrequency pulse and readout periods, and previously unrecognized susceptibility differences between fiber groups were observed in the meniscus. Magn Reson Med 67:991-1003, 2012. (c) 2011 Wiley Periodicals, Inc.