基于IVIM-DWI的成人肾脏肿瘤影像生物学标记及其病理学基础研究

本课题将在前期工作-利用磁共振弥散加权成像进行肾细胞癌弥散特性研究的基础上通过纳入肾脏肿瘤的成人患者进行体素内不相干运动模型-磁共振弥散加权成像（IVIM-DWI），探索IVIM-DWI技术在肾脏肿瘤的可重复性，优化IVIM-DWI扫描时多个扩散敏感因子（b值）的数量和分布，在此基础上探索常见肾脏肿瘤-肾透明细胞癌、乳头状肾细胞癌、嫌色细胞癌、肾盂癌、血管平滑肌脂肪瘤、嗜酸细胞腺瘤的IVIM-DWI弥散及灌注参数-真正弥散系数（D），假性弥散（D*）及灌注分数（f），同时分析各参数区别肾脏肿瘤的不同病理类型的效能，然后通过病理学研究分析肾脏肿瘤细胞密度及微血管密度，从病理学角度阐释IVIM-DWI肾脏肿瘤弥散及灌注特性的生物学基础，不仅为IVIM-DWI参数的合理阐释提供病理依据，并可判断各参数是否真正能作为肾脏肿瘤的影像生物标记，从而为成人肾脏肿瘤的定性诊断提供客观、准确的依据。

Based on our previous study-investigation of renal cell carcinom diffusion features using diffusion-weighted imaging and apparent diffusion coefficient (ADC) values, this project will enroll patients with renal tumors in light of the given criteria and all subjects will underwent intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) scans.In this study, firstly the reproducibility and repeatability of IVIM-DWI technique in renal tumors were evaluated, whichi is pivotal for IVIM-DWI application in kidney, even in abdomen; then the optimization of b values were perfomred regarding to the selection and distributioni of b values, considering both clinical and scientific requirements and patients' tolerability. Moreover the IVIM-DWI parameters-pure diffusion (D), pseudodiffusion (D*) and perfusion fraction (f) were calculated based on biexponential model, and the efficacy of distinguishing renal tumors including renal cell clear cell carcinoma, papillary renal cell carcinoma, chromophobic renal cell carcinoma , renal pelvic cancer, angiomyolipoma and oncocytoma using these parameters was evaluated. Then the diagnostic efficacy of D,D* and f in characterizing renal tumor was individually analyzed and compared between them. At last, through pathologic analysis, the pathologic types of renal tumors were determined according to the 2004 WHO classification of genitourinary tumors, then the tumor microvessel density and tumor cellularity were inspected.All these efforts can not only provide the reasonable explanation for IVIM-DWI parameters related to both diffusion and perfusion from pathologic perspective, but also determine whether or which parameters can become the imaging biomarkers of renal tumors with different entity, which eventually will provide quantitative and objective evidence for quanlitative diagnosis of renal tumors in adults.