Real-time MRI of speaking at a resolution of 33 ms: Undersampled radial FLASH with nonlinear inverse reconstruction
Real-time MRI of speaking at a resolution of 33 ms: Undersampled radial FLASH with nonlinear inverse reconstruction
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DOI：
10.1002/mrm.24276
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发表时间：
2013-02-01
影响因子：
3.3
通讯作者：
Frahm, Jens
中科院分区：
文献类型：
--
作者：
Niebergall, Aaron;Zhang, Shuo;Frahm, Jens
在说话、唱歌或吞咽期间的上气道的动态MRI研究由于需要高时间分辨率以及可能引起图像伪影（诸如信号空白和几何失真）的空气-组织界面的存在而变得复杂。这项工作利用了最近开发的实时MRI技术，以解决这些挑战，监测语音生产在3 T。该方法结合了短回波时间径向FLASH MRI序列（脉冲重复时间/回波时间= 2.22/1.44 ms;翻转角5度），具有明显的欠采样（每个图像15个径向辐条）和通过正则化非线性反演进行的图像重建。在1.5 mm平面内分辨率和33.3 ms采集时间下得到的系列图像无运动或磁化率伪影。这个应用程序的重点是在自然语音生产（标准现代德语）的主要发音的动态可视化。每秒30帧的实时MRI电影清晰地展示了嘴唇、舌头、软腭和喉在产生元音、辅音和共同发音时的时空协调。个别语音事件的定量结果与以前的非MRI结果一致。Magn Reson Med，2013年。(C)2012 Wiley Periodicals，Inc.
Dynamic MRI studies of the upper airway during speaking, singing or swallowing are complicated by the need for high temporal resolution and the presence of air-tissue interfaces that may give rise to image artifacts such as signal void and geometric distortions. This work exploits a recently developed real-time MRI technique to address these challenges for monitoring speech production at 3 T. The method combines a short-echo time radial FLASH MRI sequence (pulse repetition time/echo time = 2.22/1.44 ms; flip angle 5 degrees) with pronounced undersampling (15 radial spokes per image) and image reconstruction by regularized nonlinear inversion. The resulting serial images at 1.5 mm in-plane resolution and 33.3 ms acquisition time are free of motion or susceptibility artifacts. This application focuses on a dynamic visualization of the main articulators during natural speech production (Standard Modern German). Respective real-time MRI movies at 30 frames per second clearly demonstrate the spatiotemporal coordination of lips, tongue, velum, and larynx for generating vowels, consonants, and coarticulations. The quantitative results for individual phonetic events are in agreement with previous non-MRI findings. Magn Reson Med, 2013. (C) 2012 Wiley Periodicals, Inc.