A human cerebral and cerebellar 8-channel transceive RF dipole coil array at 7T
A human cerebral and cerebellar 8-channel transceive RF dipole coil array at 7T
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DOI：
10.1002/mrm.27476
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发表时间：
2019-02-01
影响因子：
3.3
通讯作者：
Ipek, Ozlem
中科院分区：
文献类型：
--
作者：
Clement, Jeremie D.;Gruetter, Rolf;Ipek, Ozlem
目的：提供具有大覆盖范围的高发射场穿透的偶极天线以及它们在并行发射设置中的使用在最小化超高场（即，7 T）下的B-1（+）场不均匀性方面可能是有利的。我们已经开发和评估了一个8通道射频偶极子线圈阵列成像的整个大脑和小脑区域的man.Methods：一个线圈阵列与七个偶极子建模：六个放置覆盖枕叶和颞叶，一个覆盖顶叶，两个覆盖额叶的循环。针对阵列配置模拟中心缩短和分离的偶极子，并相对于B-1（+）场在人脑中10 g组织区域上平均的最大比吸收率进行评估。构建了全脑中心缩短偶极子与额环线圈阵列，并评估其传输性能的MR图像，B-1（+）-field，和homogeneity.Results：在模拟中，偶极子阵列表现出相当的性能，以覆盖全脑。然而，为了便于建造，中心缩短的偶极子受到青睐。高空间分辨率的人脑解剖图像与线圈阵列表现出大脑皮层和cerebellum.Conclusions的全覆盖：8通道中心缩短的偶极子和额环线圈阵列承诺显着的效率在高度挑战性的地区，如小脑，和相位只有全脑的RF匀场可以大大有利于超高场磁共振成像的人脑在7 T。
Purpose: Dipole antennas that provide high transmit field penetration with large coverage, and their use in a parallel transmit setup, may be advantageous in minimizing B-1(+)-field inhomogeneities at ultra-high field, i.e 7T. We have developed and evaluated an 8-channel RF dipole coil array for imaging the entire cerebral and cerebellar regions in man.Methods: A coil array was modeled with seven dipoles: six placed covering the occipital and temporal lobes; one covering the parietal lobe; and two loops covering the frontal lobe. Center-shortened and fractionated dipoles were simulated for the array configuration and assessed with respect to B-1(+)-field at maximum specific absorption rate averaged over 10 g tissue regions in human brain. The whole-brain center-shortened dipoles with frontal loops coil array was constructed and its transmit properties were assessed with respect to MR images, B-1(+)-field, and homogeneity.Results: In simulations, the dipole arrays showed comparable performances to cover the whole-brain. However, for ease of construction, the center-shortened dipole was favored. High spatial resolution anatomical images of the human brain with the coil array demonstrated a full coverage of the cerebral cortex and cerebellum.Conclusions: The 8-channel center-shortened dipoles and frontal loops coil array promises remarkable efficiency in highly challenging regions as the cerebellum, and phase-only RF shimming of whole-brain could greatly benefit ultra-high field magnetic resonance imaging of the human brain at 7T.