Sajewski Andrea N, Santini Tales, DeFranco Anthony, Berardinelli Jacob, Jin Hecheng, Li Jinghang, Chu Cong, Berardo Jeremy J, Ibrahim Tamer S
Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Magn Reson Med. 2025 Oct;94(4):1804-1816. doi: 10.1002/mrm.30563. Epub 2025 May 20.
To develop an radiofrequency (RF) shimming approach for operating the 2nd Generation Tic Tac Toe RF coil system (60 transmit channels integrated with 32-channel receive insert) for routine use in 7T neuro MRI on the single transmit mode.
RF simulations were performed and used to develop non-subject-specific RF shim cases over three anatomically detailed head models: adult male, adult female, and child female. Multi-ROI shimming strategies were developed and implemented. maps and in vivo images were acquired on the single transmit mode of a 7T scanner using the RF shim cases derived from the computer simulations.
The availability of 60 transmit channels enables more control over efficiency, specific absorption rate (SAR) efficiency, and homogeneity using RF shimming. On the single transmit mode, the 2nd generation Tic Tac Toe RF coil system consistently provides homogeneous field distribution with extended coverage into the temporal lobes, cerebellum, reaching all the way to C5-C6. Safe levels of SAR are also achieved.
By using a non-subject specific RF shimming approach derived from computer simulations, the 2nd generation Tic Tac Toe RF coil system allows for robust, routine neuroimaging (>1750 in vivo scanning sessions over the past 28 months) at 7T in single transmit mode.
开发一种射频（RF）匀场方法，用于操作第二代井字棋射频线圈系统（60个发射通道与32通道接收插入件集成），以便在7T神经磁共振成像中以单发射模式进行常规使用。
进行了射频模拟，并用于在三个解剖学详细的头部模型上开发非特定受试者的射频匀场方案：成年男性、成年女性和儿童女性。开发并实施了多感兴趣区匀场策略。使用从计算机模拟得出的射频匀场方案，在7T扫描仪的单发射模式下采集了图谱和体内图像。
60个发射通道的可用性使得能够通过射频匀场对效率、比吸收率（SAR）效率和均匀性进行更多控制。在单发射模式下，第二代井字棋射频线圈系统始终能提供均匀的磁场分布，覆盖范围扩展到颞叶、小脑，一直到C5 - C6。还实现了安全水平的SAR。
通过使用从计算机模拟得出的非特定受试者射频匀场方法，第二代井字棋射频线圈系统允许在7T下以单发射模式进行强大的常规神经成像（在过去28个月内进行了超过1750次体内扫描）。
