Institute of Diagnostic and Interventional Radiology, University Hospital Zurich.
Department of Neuroradiology, University Hospital Freiburg.
Magn Reson Med Sci. 2019 Apr 10;18(2):150-157. doi: 10.2463/mrms.mp.2018-0004. Epub 2018 Nov 9.
Diffusion tensor imaging (DTI) adds functional information to morphological magnetic resonance neurography (MRN) in the assessment of the brachial nerve plexus. To determine the most appropriate pulse sequence in scan times suited for diagnostic imaging in clinical routine, we compared image quality between simultaneous multi-slice readout-segmented (rs-DTI) and conventional single-shot (ss-DTI) echo-planar imaging techniques.
Institutional Review Board (IRB) approved study including 10 healthy volunteers. The supraclavicular brachial plexus, covering the nerve roots and trunks from C5 to C7, was imaged on both sides with rs-DTI and ss-DTI. Both sequences were acquired in scan times <7 min with b-values of 900 s/mm and with isotropic spatial resolution.
In rs-DTI image, the overall quality was significantly better and distortion artifacts were significantly lower (P = 0.001-0.002 and P = 0.001-0.002, respectively) for both readers. In ss-DTI, a trend toward lower degree of ghosting and motion artifacts was elicited (reader 1, P = 0.121; reader 2, P = 0.264). No significant differences between the two DTI techniques were found for signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR) and fractional anisotropy (FA) (P ≥ 0.475, P ≥ 0.624, and P ≥ 0.169, respectively). Interreader agreement for all examined parameters and all sequences ranged from intraclass correlation coefficient (ICC) 0.064 to 0.905 and Kappa 0.40 to 0.851.
Incomparable acquisition times rs-DTI showed higher image quality and less distortion artifacts than ss-DTI. The trend toward a higher degree of ghosting and motion artifacts in rs-DTI did not deteriorate image quality to a significant degree. Thus, rs-DTI should be considered for functional MRN of the brachial plexus.
弥散张量成像（DTI）为臂丛神经磁共振神经成像（MRN）提供了形态学功能信息。为了确定在适合临床常规诊断成像的扫描时间内最合适的脉冲序列，我们比较了同时多切片读出分段（rs-DTI）和传统单次激发（ss-DTI）平面回波成像技术的图像质量。
本研究经机构审查委员会（IRB）批准，纳入 10 名健康志愿者。对双侧锁骨上臂丛神经，从 C5 到 C7 的神经根和干进行成像，分别使用 rs-DTI 和 ss-DTI 进行扫描。两种序列的扫描时间均小于 7 分钟，b 值为 900 s/mm，空间分辨率各向同性。
在 rs-DTI 图像中，两位读者均认为整体质量明显更好，失真伪影明显更低（P = 0.001-0.002 和 P = 0.001-0.002）。在 ss-DTI 中，鬼影和运动伪影程度较低，但无统计学差异（读者 1，P = 0.121；读者 2，P = 0.264）。两种 DTI 技术的信噪比（SNR）、对比噪声比（CNR）和各向异性分数（FA）无显著差异（P ≥ 0.475，P ≥ 0.624，P ≥ 0.169）。所有检查参数和所有序列的两位读者间的一致性，从组内相关系数（ICC）0.064 到 0.905 和 Kappa 值 0.40 到 0.851 不等。
虽然扫描时间不可比，但 rs-DTI 的图像质量更高，失真伪影更小。rs-DTI 中鬼影和运动伪影程度较高的趋势并未显著降低图像质量。因此，rs-DTI 应考虑用于臂丛神经的功能 MRN。
