分段读出平面回波成像和多b值弥散加权成像与前列腺癌整体组织病理切片的对照研究及影像3D模型的构建

To obtain biexponential and stretched model diffusion weighted imaging(DWI), readout-segmented echo-planar imaging (RS-EPI) DWI, and conventional DWI data of prostate cancer from 30 patients, and compaired it to the whole pathologic sections of prostate cancer. The fast component of ADC (ADCf）, slow component of ADC (ADCs） and fraction of fast component (f) of bieponential model, distributed diffusion coefficients ( DDC) and indexαfrom stretched model，ad well as RS-EPI ADC and normal ADC value will be observed for different prostate tissues. The difference of these data between prostate and non-cancer tissue were evaluated, and the abiltiy of these data to differentiate the prostate and non-cancer tissue will be also assessed,the optional cutoff value will be also obtained. Moreover, these data would be correlated to the gleason score, cell density to evaluate their efficiency to reflect the degree of malignancy and micro environment of prostate cancer. The volume of prostate cancer of 30 patients would be measure by these DWI data and pathological section respectively, and compared to assess the accuracy of DWI to measure the volume of prostate cancer.The 3D imaging model would be also constructed to these data the pridict the gleason score of prostate, and evaluate its correlation with whole pathologic sections, and the ability to measure the volume of prostate cancer.

通过统计和分析30例术前前列腺癌患者前列腺的双指数DWI，广延指数DWI，分段读出平面回波成像（RS-EPI）和常规DWI数据，与整体组织病理切片对照，评估良恶性组织在以上参数的差异。主要考察参数为应用双指数函数的ADC值快弥散成分（ADCf）,慢弥散成分（ADCs），和快弥散成分比重（f）, 广延指数DWI的分布弥散系数（DDC）和广延系数α，以及RS-EPI ADC 和常规ADC值,应用以上参数对良恶性病变进行鉴别诊断，获取最佳界值，明确诊断效能及建立诊断标准；双指数和广延指数DWI，RS-EPI和常规DWI各参数与gleason分级、细胞密度的相关性分析，考察以上参数评估前列腺癌恶性程度及组织微环境的效能。建立3D模型，测量30例患者DWI上肿瘤体积，对病理切片对照，并与实际面积进行相关性分析，评价DWI测量肿瘤体积的准确性,以及对恶性程度的预测效能。

前列腺癌是我国老年男性高发疾病，目前常规MRI方法诊断效果有待提高，本课题通过对前列腺癌患者行双指数和广延指数弥散加权成像（diffusion weighted imaging,DWI)，分段读出平面回波成像（readout-segmented echo-planar imaging, RS-EPI） DWI检查，并计算相关参数，并与整体组织切片作对照; 确立RS-EPI DWI较常规DWI检查有更高的图像质量及诊断效能，明确对应的表观弥散系数（apparent diffusion coefficient，ADC）值诊断阈值。通过统计和分析术前前列腺癌患者前列腺的双指数DWI（ADCf、ADCs和f），广延指数DWI[分布弥散系数(distribution diffusion coefficient, DDC)及α]和常规DWI（ADC值）数据，与整体组织病理切片对照，评估良恶性组织在以上参数的差异。应用以上参数对良恶性病变进行鉴别诊断，获取最佳界值，明确诊断效能及建立诊断标准，证实双指数DWI鉴别诊断中央腺体前列腺癌效能高于常规DWI。对双指数和广延指数DWI，RS-EPI和常规DWI各参数与gleason分级、组织比例进行相关性分析，证明双指数和广延指数DWI，RS-EPI DWI参数与恶性程度明显相关，双指数DWI可灵敏反映肿瘤组织内腺体和细胞间质结构的改变。应用双指数和广延指数DWI，RS-EPI和常规DWI的数据，检测和定位可见的肿瘤，并测量最大层面面积，与整体组织病理切片比较，评价肿瘤检出率及定位准确性，证实以上参数测量的前列腺癌体积（以最大层面面积间接反映）与病理测量体积明显相关。建立3D模型坐标系，评价不同参数中肿瘤与整体组织病理切片中前列腺癌组织的对应关系，应用3D模型及坐标系引导下前列腺穿刺活检，证明MRI 3D坐标系统可较精确引导穿刺，具有较高的阳性预测值，相对常规前列腺癌穿刺比较可能减少穿刺针数及创伤。