Approaching Ultimate Intrinsic SNR in a Uniform Spherical Sample with Finite Arrays of Loop Coils.
Approaching Ultimate Intrinsic SNR in a Uniform Spherical Sample with Finite Arrays of Loop Coils.
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DOI：
10.1002/cmr.b.21268
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发表时间：
2014-08
影响因子：
0.9
通讯作者：
Lattanzi, Riccardo
中科院分区：
文献类型：
--
作者：
Vaidya, Manushka V.;Sodickson, Daniel K.;Lattanzi, Riccardo
关键词：
我们研究了在何种程度上，以何种速率，最终内在（UI）信噪比（SNR）可以使用有限的射频探测器阵列接近。我们使用基于二进格林函数的全波电磁场模拟来比较均匀球体周围环路阵列的信噪比与最终固有信噪比（usisnr），以增加磁场强度，体素位置，球体尺寸和加速因子范围内的元素数量。我们在多个成像平面上评估了线圈导体损耗的影响以及各种不同几何布置（如“头盔”和“开极”配置）的性能。我们的研究结果表明，中心的usnr可以通过环绕阵列快速接近，而在表面附近，针对体素位置量身定制的正交检测配置是最佳的，性能明显较低。线圈噪声在高场下可以忽略不计，在高场下采样噪声占主导地位。实际阵列配置（如头盔）的中心信噪比类似于密实排列。观察到的趋势可以为改进线圈设计提供物理见解。
We investigated to what degree and at what rate the ultimate intrinsic (UI) signal-to-noise ratio (SNR) may be approached using finite radiofrequency detector arrays. We used full-wave electromagnetic field simulations based on dyadic Green’s functions to compare the SNR of arrays of loops surrounding a uniform sphere with the ultimate intrinsic SNR (UISNR), for increasing numbers of elements over a range of magnetic field strengths, voxel positions, sphere sizes, and acceleration factors. We evaluated the effect of coil conductor losses and the performance of a variety of distinct geometrical arrangements such as “helmet” and “open-pole” configurations in multiple imaging planes. Our results indicate that UISNR at the center is rapidly approached with encircling arrays and performance is substantially lower near the surface, where a quadrature detection configuration tailored to voxel position is optimal. Coil noise is negligible at high field, where sample noise dominates. Central SNR for practical array configurations such as the helmet is similar to that of close-packed arrangements. The observed trends can provide physical insights to improve coil design.
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影响因子：
3.3
作者：
Sodickson, DK;Manning, WJ
通讯作者：
Manning, WJ
影响因子：
3.3
作者：
Griswold, MA;Jakob, PM;Haase, A
通讯作者：
Haase, A
影响因子：
3.3
作者：
Collins, CM;Smith, MB
通讯作者：
Smith, MB
影响因子：
2.9
作者：
Lattanzi, Riccardo;Grant, Aaron K.;Polimeni, Jonathan R.;Ohliger, Michael A.;Wiggins, Graham C.;Wald, Lawrence L.;Sodickson, Daniel K.
通讯作者：
Sodickson, Daniel K.
影响因子：
3.3
作者：
ROEMER, PB;EDELSTEIN, WA;MUELLER, OM
通讯作者：
MUELLER, OM