多模态MRI精确定量克罗恩病肠壁纤维化的容积组方研究

Intestinal fibrosis is not only an important pathological feature of Crohn's disease, but also a major indicator to determine the disease activity, to assess the therapeutic efficacy and to evaluate the prognosis of the disease. Previous studies have shown that multi-modal quantitative MRI techniques (dynamic contrast-enhanced MRI and multiple parameter DWI) can quantify fibrosis in solid organs. Due to the involuntary movements of the bowl wall and the magnetic susceptibility artifacts near gas-liquid interface, it is difficult to accurately measure quantitative MRI parameters of the intestines. The preliminary studies of our research group found out that the threonine manganese chelate solution can produce dark lumen in MRE, reduce artifacts and improve the quality of MR images, making the application of quantitative MRI technology possible. Volumetric histogram analysis can show the characteristics of the imaging more comprehensively, thus could help to achieve precise quantitation. In this study, using threonine manganese chelate solution as an enteral contrast agent, we will investigate the accuracy of volumetric histogram analysis of multi-modal quantitative MRI in the evaluation of intestinal fibrosis in both acute and chronic Crohn's disease animal models.

肠壁纤维化是克罗恩病的重要病理特征，也是判断病变活动性、评价疗效及预后的主要指标。前期研究表明，多模态定量MRI技术（动态增强MRI和多参数DWI）可定量实质脏器纤维化。因肠道不自主运动和气液界面的磁敏感伪影，难以测定和精确定量纤维化。本课题组前期研究发现，苏氨酸锰螯合物溶液可形成黑腔对比，优化成像减少伪影，使应用定量MRI技术成为可能。容积组方图分析能更好的展现组织影像学特征，实现精确定量。本研究拟采用苏氨酸锰螯合物溶液作为肠腔对比剂，结合多模态定量MRI技术，对克罗恩病急、慢性动物模型肠壁纤维化进行容积组方分析，从而达到精确定量研究。

肠壁纤维化是克罗恩病的重要病理特征，也是判断病变活动性、评价疗效及预后的主要指标。既往研究表明，多模态定量MRI技术可定量实质脏器纤维化。而肠腔等空腔脏器，由于肠道不自主运动和气液界面的磁敏感伪影，功能成像成为困难，其定量指标的可重复性及价值在肠道疾患中的应用受到限制。本课题组创新性的采用营养添加剂——苏氨酸锰螯合物溶液的顺磁性效应，通过体外测量并计算其对应弛豫率，计算出可达到肠腔双黑腔对比的浓度。而进一步在活体大鼠内验证该理论，大大减少了磁敏感伪影，优化成像和功能成像。同时，该模型的成功建立，为后续克罗恩病的致病机制和疗效评价提供了基础。同时，基于上述科学假说基础上，拓展采用多模态定量MRI技术结合组学工具，在腹部及肠道病变的鉴别诊断方面进行了应用。