Graduate School of Health Sciences, Hokkaido University, North-12 West-5, Kita-ku, Sapporo, 060-0812, Japan.
AIC Yaesu Clinic, 2-1-18, Nihonbashi, Chuo-ku, Tokyo, Japan.
Rheumatol Int. 2019 Dec;39(12):2111-2118. doi: 10.1007/s00296-019-04425-2. Epub 2019 Aug 27.
The objective of this study is to investigate computed DWI (cDWI) as an alternative method to contrast-enhanced MRI in comparison with directory measured DWI (mDWI) and apparent diffusion coefficient (ADC) for differentiating synovial proliferation from joint effusion. Nine patients suspected with RA (5 women) were included in this study. A radiologist identified region of interest (ROI) based on STIR, and evaluated using a 5-point grading scale of 0 (fluid) to 4 (synovial proliferation) according to the degree of contrast enhancement within the ROI. cDWI was synthesized for b values from 1000 to 2000 at 200 s/mm intervals using the combination of b values at mDWI. In addition to ADC values, contrast ratios were calculated using signal intensity for each ROI on the mDWI and cDWI. Visual assessment by a radiologist was conducted between pairs of STIR image and mDWI or cDWI. ROI grades were most significantly correlated with cDWI based on b values of 400-1000 s/mm (r = 0.405, p < 0.01). The area under the curve of cDWI based on b values of 400-1000 s/mm (0.762) was larger than that of ADC values (0.570-0.608) when comparing low versus high contrast enhancement grades. Both cDWI (200-1000) and cDWI (400-1000) demonstrated high sensitivity and specificity in visual assessment (84.6% and 66.7%, respectively). The cDWI based on b values of 400-1000 s/mm may be useful for noninvasive differentiation of synovial proliferation from joint effusion in hand arthritis.
本研究旨在探索扩散加权成像（DWI）在对比增强磁共振成像（MRI）中的应用，通过比较目录测量 DWI（mDWI）和表观扩散系数（ADC），以区分滑膜增生和关节积液。本研究纳入了 9 名疑似类风湿关节炎（RA）的患者（5 名女性）。放射科医生根据 STIR 图像识别感兴趣区（ROI），并根据 ROI 内的对比增强程度，使用 0（液体）至 4（滑膜增生）的 5 分等级评分标准进行评估。通过 mDWI 中 b 值的组合，从 1000 到 2000 合成 cDWI，b 值间隔为 200 s/mm。除了 ADC 值外，还计算了每个 ROI 在 mDWI 和 cDWI 上的信号强度的对比比。放射科医生对 STIR 图像和 mDWI 或 cDWI 进行了两两之间的视觉评估。ROI 评分与基于 400-1000 s/mm b 值的 cDWI 最为显著相关（r=0.405，p<0.01）。当比较低对比度增强分级和高对比度增强分级时，基于 400-1000 s/mm b 值的 cDWI 的曲线下面积（AUC）（0.762）大于 ADC 值（0.570-0.608）。cDWI（200-1000）和 cDWI（400-1000）在视觉评估中均表现出较高的灵敏度和特异性（分别为 84.6%和 66.7%）。基于 400-1000 s/mm b 值的 cDWI 可能有助于对手关节炎中滑膜增生和关节积液的无创性鉴别。
