Qi Li-Ping, Zhong Zheng, Sun Ying-Shi, Li Xiao-Ting, Tang Lei, Zhou Xiaohong Joe
Department of Radiology, Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University Cancer Hospital and Institute, Beijing, China.
Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL, USA.
Heliyon. 2023 May 26;9(6):e16702. doi: 10.1016/j.heliyon.2023.e16702. eCollection 2023 Jun.
This study proposed to investigate the optimal selection of b-values in diffusion-weighted imaging for distinguishing malignant from benign mediastinal lymph nodes. Diffusion-weighted imaging with six b-values was performed on 35 patients at 1.5 T. Image quality score, signal-to-noise ratio, and relative contrast ratio of lymph node to chest muscle were compared between the diffusion-weighted images with a b-value up to 800 and 1000 s/mm. Using a lower and an upper b-value in the range of 0-1000 s/mm, eight apparent diffusion coefficient maps were obtained from a mono-exponential model. Receiver operating characteristic analysis was employed to evaluate the performance of the apparent diffusion coefficients for distinguishing malignant from benign mediastinal lymph nodes by using the area under the curve as a criterion. The mean image quality score and the relative contrast ratio showed no difference between b-values of 800 and 1000 s/mm. In the receiver operating characteristic analysis, the areas under the curve of apparent diffusion coefficient with b-value pairs of (0, 800), (0, 1000), and (50, 800) s/mm were significantly higher than those from the other b-value pairs. No significant difference was observed among the three b-value pairs. Apparent diffusion coefficient obtained from b-value pairs of (0, 800), (0, 1000), and (50, 800) s/mm showed superior diagnostic performance compared to the other b-value combinations. Based on several practical considerations, the b-value pair of (50, 800) s/mm is recommended for differential diagnosis of mediastinal lymph nodes.
本研究旨在探讨在扩散加权成像中区分纵隔恶性与良性淋巴结的b值最佳选择。对35例患者在1.5T条件下进行了具有六个b值的扩散加权成像。比较了b值高达800和1000s/mm²的扩散加权图像之间的图像质量评分、信噪比以及淋巴结与胸肌的相对对比率。在0 - 1000s/mm²范围内使用较低和较高的b值，从单指数模型获得了八幅表观扩散系数图。采用受试者操作特征分析，以曲线下面积为标准评估表观扩散系数区分纵隔恶性与良性淋巴结的性能。800和1000s/mm²的b值之间，平均图像质量评分和相对对比率无差异。在受试者操作特征分析中，b值对为(0, 800)、(0, 1000)和(50, 800)s/mm²的表观扩散系数曲线下面积显著高于其他b值对。这三个b值对之间未观察到显著差异。与其他b值组合相比，b值对为(0, 800)、(0, 1000)和(50, 800)s/mm²所获得的表观扩散系数显示出更好的诊断性能。基于一些实际考虑，推荐b值对(50, 800)s/mm²用于纵隔淋巴结的鉴别诊断。
