School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 110, Taiwan.
Department of Medical Imaging, Taipei Medical University Hospital, Taipei Medical University, Taipei 110, Taiwan.
Tomography. 2021 Mar 27;7(2):107-119. doi: 10.3390/tomography7020010.
The presence of a swallow-tail sign in the nigrosome-1 with hyperintense signal shown on the susceptibility-weighted imaging (SWI) has been shown to be sensitive in detecting the abnormal iron deposits in this area. A systematic evaluation in healthy subjects is required before this tool can be recommended in a widespread application. We evaluated a simple and practical SWI approach using a multiecho gradient-echo sequence with an improved contrast-to-noise ratio (CNR). We also evaluated the association of the neuromelanin imaging contrast behavior with the susceptibility and relaxation measurements. Twenty-five older and 23 young healthy adults were evaluated. The CNRs of the nigrosome-1 were compared along with method and group. Correlations of the nigrosome-1 neuromelanin signal in the neuromelanin-sensitive imaging with CNRs in the susceptibility, T1 and T2 mappings were examined. Two different coils were used to confirm the reproducibility. Compared with the single-echo, multiecho SWI can improve the CNR of the swallow-tail sign. We found significant correlations between neuromelanin signal and CNRs in the susceptibility and T2 mappings, and T1 value. The older subjects exhibited increased CNRs compared with the young adults. No significant difference was observed in the measurements between 20 and 64 channels. The multiecho technique allows the high-quality nigrosome-1 images in SWI and allows for a joint analysis of T2* and quantitative-susceptibility mapping at high spatial resolution. The correlations of neuromelanin-sensitive imaging with susceptibility and T2 imply that the iron content in the nigrosome-1 may have significant influences on the hyperintensity of neuromelanin in the magnetization transfer-related contrast.
在磁敏感加权成像 (SWI) 上显示黑质 1 区高信号的燕尾征的存在已被证明对检测该区域异常铁沉积具有高度敏感性。在广泛应用之前，需要对健康受试者进行系统评估。我们使用具有改进对比噪声比 (CNR) 的多回波梯度回波序列评估了一种简单实用的 SWI 方法。我们还评估了神经黑色素成像对比度与磁化率和弛豫测量的相关性。评估了 25 名老年人和 23 名年轻健康成年人。比较了黑质 1 区的 CNR 值以及方法和组。检查了神经黑色素敏感成像中黑质 1 区神经黑色素信号与磁化率和 T1 和 T2 映射中的 CNR 之间的相关性。使用两种不同的线圈来确认可重复性。与单回波相比，多回波 SWI 可以提高燕尾征的 CNR。我们发现神经黑色素信号与磁化率和 T2 映射中的 CNR 以及 T1 值之间存在显著相关性。与年轻人相比，老年人的 CNR 更高。在 20 到 64 个通道之间的测量中未观察到显著差异。多回波技术允许在 SWI 中获得高质量的黑质 1 图像，并允许在高空间分辨率下联合分析 T2*和定量磁化率图。神经黑色素敏感成像与磁化率和 T2 的相关性表明，黑质 1 中的铁含量可能对磁化传递相关对比中的神经黑色素的高信号有重要影响。
