OBJECTIVE To prospectively evaluate the ability of IVIM-DWI and DCE-MRI in detecting early activity of sacroiliitis in rat model of ankylosing spondylitis by comparing with pathological results. METHODS 20 wistar male rats were induced by bovine proteoglycan combined with complete/incomplete Freund's adjuvant as model group, and 20 healthy male rats were used as the control group. The parameters of IVIM-DWI and DCE-MRI in synovial regions of SIJ were measured respectively at 7th, 12th, 17th, and 22th weeks after the last induction, and the pathological features of SIJ were taken also, further studying the pathological characteristics of sacroiliac region. Independent sample t-test and one-way ANOVA were used for statistical analysis. The prediction parameters and diagnostic efficiency were compared by ROC curve. RESULTS There was no significant difference of image parameters between the model and control groups at the 7th, 12th weeks after the last induction, and there were no positive findings in histopathological examination at the same time. At the 17th week after induction, the f and Fenh%, Senh% between the model and the control groups were statistically significant. At the 22th week, there was a statistically significant increase all the values in model group than those in control group (P < 0.05). Histologic examination confirmed inflmmtorycell infiitrtion at the 17th week and pannus forming of synovium on the surface of cartilage at the 22th week in the model groups. The Fenh%, Senh%, Dslow and f had the moderate diagnostic efficiency and the areas under the curve were 0.77, 0.75, 0.77 and 0.82 respectively. The Senh% demonstrated the highest sensitivity (71.4%) and f demonstrated the highest specificity (95.0%). CONCLUSION IVIM-DWI and DCE-MRI can be used as the sensitive imaging methods to detect and accurate diagnosis the early activity of sacroiliitis in AS.

中文翻译：

---

体素不相干运动扩散加权成像和动态对比增强MRI在评估强直性脊柱炎大鼠model肌炎活动中的价值。

目的通过与病理结果比较，前瞻性评价IVIM-DWI和DCE-MRI检测强直性脊柱炎大鼠模型sa肌早期活动的能力。方法以牛蛋白聚糖联合完全/不完全弗氏佐剂诱导Wistar雄性大鼠20只为模型组，以健康雄性大鼠20只为对照组。在最后一次诱导后第7、12、17和22周分别测量SIJ滑膜区的IVIM-DWI和DCE-MRI参数，并获取SIJ的病理特征，进一步研究of的病理特征地区。使用独立样本t检验和单向方差分析进行统计分析。通过ROC曲线比较预测参数和诊断效率。结果在最后一次诱导后的第7、12周，模型组和对照组之间的图像参数没有显着差异，同时在组织病理学检查中也没有发现阳性。诱导后第17周，模型组与对照组之间的f和Fenh％，Senh％具有统计学意义。在第22周，模型组所有值均比对照组有统计学意义的增加（P <0.05）。组织学检查证实，模型组在第17周出现了纤维变性细胞变形，在第22周证实了在软骨表面滑膜形成了血管pan。Fenh％，Senh％，Dslow和f具有中等诊断效率，曲线下面积分别为0.77、0.75、0.77和0.82。Senh％表现出最高的敏感性（71.4％），f表现出最高的特异性（95.0％）。结论IVIM-DWI和DCE-MRI可作为灵敏的影像学方法，以检测和准确诊断AS AS肌炎的早期活动。