Dual-Source Parallel RF Transmission for Clinical MR Imaging of the Spine at 3.0 T: Intraindividual Comparison with Conventional Single-Source Transmission
Dual-Source Parallel RF Transmission for Clinical MR Imaging of the Spine at 3.0 T: Intraindividual Comparison with Conventional Single-Source Transmission
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DOI：
10.1148/radiol.10092146
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发表时间：
2010-12-01
期刊：
影响因子：
19.7
通讯作者：
Willinek, Winfried A.
中科院分区：
文献类型：
--
作者：
Nelles, Michael;Koenig, Roy S.;Willinek, Winfried A.
目的：为了前瞻性和intraindividually比较单源射频（RF）激励和双源并行RF激励在3.0 T磁共振（MR）成像的spinity.Materials和方法：机构审查委员会批准和书面知情同意患者获得。3.0 T MR成像系统的射频功率通过使用独立的射频发射通道分配到系统的体线圈的两个端口。与单源RF激发相比，双源并行RF激发的最大B 1场强得以维持。根据双源并行射频激发的修订射频设置减少了重复时间，同时保持了特定的能量吸收限制。30例患者接受了双源并行射频激励和非双源并行射频激励检查。诊断质量由两名放射科医生根据四点分级系统独立评估。计算单源射频激励和双源并行射频激励下参考组织和椎骨之间的图像对比度（CR）。结果：双源并行射频激励实现的平均加速度为36%（范围，18%-50%）。通过使用双源并行射频传输，三站全脊柱检查的总成像时间缩短了三分之一。对于研究的所有病例，两种方法之间的诊断图像质量无显著差异，观察者间一致性良好（Kendall tau-b，0.50-0.84）。观察到的图像对比度变化主要是小的（
Purpose: To prospectively and intraindividually compare single-source radiofrequency (RF) excitation and dual-source parallel RF excitation in 3.0-T magnetic resonance (MR) imaging of the spine.Materials and Methods: Institutional review board approval and written informed patient consent were obtained. The RF power of a 3.0-T MR imaging system was distributed to two ports of the body coil of the system by using independent RF transmit channels. The maximum B 1 field strength for dual-source parallel RF excitation was maintained, as compared with single-source RF excitation. The repetition time was reduced according to the revised RF setup with dual-source parallel RF excitation while maintaining specific energy absorption limitations. Thirty patients were examined with and without dual-source parallel RF excitation. Diagnostic quality was assessed independently by two radiologists according to a four-point grading system. Image contrast ratios (CRs) were calculated between reference tissues and vertebrae for single-source RF excitation and dual-source parallel RF excitation.Results: The mean acceleration achieved with dual-source parallel RF excitation was 36% (range, 18%-50%). The total imaging duration of a three-station total spinal examination was reduced by one-third by using dual-source parallel RF transmission. For all cases investigated, diagnostic image quality without significant differences between the two methods and with a good interobserver agreement was achieved (Kendall tau-b, 0.50-0.84). The observed image contrast changes were predominantly small (