Breckwoldt Michael O, Stock Christian, Xia Annie, Heckel Andreas, Bendszus Martin, Pham Mirko, Heiland Sabine, Bäumer Philipp
From the *Department of Neuroradiology, Heidelberg University Hospital, †Institute of Medical Biometry and Informatics, and ‡Section of Experimental Radiology, Heidelberg University Hospital, University of Heidelberg, Heidelberg, Germany.
Invest Radiol. 2015 Aug;50(8):498-504. doi: 10.1097/RLI.0000000000000156.
The aim of this study was to determine whether quantitative diffusion tensor imaging (DTI) adds diagnostic accuracy in magnetic resonance neurography.
This prospective study was approved by the institutional review board. We enrolled 16 patients with peripheral polyneuropathy of various etiologies involving the upper arm and 30 healthy controls. Magnetic resonance neurography was performed at 3 T using transverse T2-weighted (T2-w) turbo spin echo and spin echo planar imaging diffusion-weighted sequences. T2-weighted normalized signal (nT2), fractional anisotropy (FA), apparent diffusion coefficient (ADC), radial diffusivity (RD), and axial diffusivity (AD) of the median, ulnar, and radial nerves were quantified after manual segmentation. Diagnostic performance of each separate parameter and combinations of parameters was assessed using the area under the receiver operating characteristic curve (AUC). Bootstrap validation was used to adjust for potential overfitting.
Average nT2, ADC, RD, and AD values of the median, ulnar, and radial nerve were significantly increased in neuropathy patients compared with that in healthy controls (nT2, 1.49 ± 0.05 vs 1.05 ± 0.05; ADC, 1.4 × 10(-3) ± 2.8 × 10(-5) mm(2)/s vs 1.1 × 10(-3) ± 1.3 × 10(-5) mm(2)/s; RD, 9.5 × 10(-4) ± 2.9 × 10(-5) mm(2)/s vs 7.2 × 10(-4) ± 1.3 × 10(-5) mm(2)/s; AD, 2.3 × 10(-3) ± 3.7 × 10(-5) mm(2)/s vs 2.0 × 10(-3) ± 2.2 × 10(-5) mm(2)/s; P < 0.001 for all comparisons). Fractional anisotropy values were significantly decreased in patients (0.51 ± 0.01 vs 0.59 ± 0.01; P < 0.001). T2-weighted normalized signal and DTI parameters had comparable diagnostic accuracy (adjusted AUC: T2-w, 0.92; FA, 0.88; ADC, 0.89; AD, 0.84; RD, 0.86). Combining DTI parameters significantly improved the diagnostic accuracy over single-parameter analysis. In addition, the combination of nT2 with DTI parameters yielded excellent adjusted AUCs up to 0.97 (nT2 + FA).
Diffusion tensor imaging has high diagnostic accuracy in peripheral neuropathy. Combining DTI with T2 can outperform T2-w imaging alone and provides added value in magnetic resonance neurography.
本研究旨在确定定量扩散张量成像（DTI）是否能提高磁共振神经成像的诊断准确性。
本前瞻性研究经机构审查委员会批准。我们纳入了16例病因各异的累及上臂的周围性多发性神经病患者和30名健康对照者。在3T磁共振成像仪上采用横向T2加权（T2-w）快速自旋回波和自旋回波平面成像扩散加权序列进行磁共振神经成像。手动分割后，对正中神经、尺神经和桡神经的T2加权归一化信号（nT2）、各向异性分数（FA）、表观扩散系数（ADC）、径向扩散率（RD）和轴向扩散率（AD）进行定量分析。使用受试者操作特征曲线（AUC）下的面积评估每个单独参数及参数组合的诊断性能。采用自助法验证以调整潜在的过度拟合。
与健康对照者相比，神经病患者正中神经、尺神经和桡神经的平均nT2、ADC、RD和AD值显著升高（nT2：1.49±0.05 vs 1.05±0.05；ADC：1.4×10⁻³±2.8×10⁻⁵mm²/s vs 1.1×10⁻³±1.3×10⁻⁵mm²/s；RD：9.5×10⁻⁴±2.9×10⁻⁵mm²/s vs 7.2×10⁻⁴±1.3×10⁻⁵mm²/s；AD：2.3×10⁻³±3.7×10⁻⁵mm²/s vs 2.0×10⁻³±2.2×10⁻⁵mm²/s；所有比较P<0.001）。患者的各向异性分数值显著降低（0.51±0.01 vs 0.59±0.01；P<0.001）。T2加权归一化信号和DTI参数具有相当的诊断准确性（调整后的AUC：T2-w为0.92；FA为0.88；ADC为0.89；AD为0.84；RD为0.86）。与单参数分析相比，联合DTI参数显著提高了诊断准确性。此外，nT2与DTI参数的组合产生了高达0.97的出色调整后AUC（nT2+FA）。
扩散张量成像在周围神经病中具有较高的诊断准确性。将DTI与T2相结合的表现优于单独的T2-w成像，在磁共振神经成像中具有附加价值。
