【作者】 张瑾；

【导师】 周纯武；

【作者基本信息】 北京协和医学院 ， 影像医学与核医学， 2011， 博士

【摘要】 第一部分：肾脏肿瘤的3.OT MR扩散加权成像研究目的：探讨扩散加权成像对不同良恶性、不同病理类型肾脏肿瘤、不同级别的透明细胞性肾癌的鉴别诊断价值。材料与方法：对171名临床怀疑肾脏肿瘤的患者(175个病灶)术前行3.OT常规MR及扩散加权(DWI)MR扫描。其中男性110例,女性61例。所有病例均经手术病理证实。DWI序列扫描b值为800s/mm2。使用AW4.4工作站分别测量肿瘤及肾脏实质的表观扩散系数(ADC值)。对不同良恶性、不同病理类型肾脏肿瘤、不同级别的透明细胞性肾癌的ADC值进行比较及统计学分析。结果：在175个病灶中有良性病灶30个,恶性病灶145个。良性病灶包括血管平滑肌脂肪瘤21个,嗜酸细胞腺瘤5个,其它良性肿瘤4个。恶性病灶包括透明细胞性肾癌110个,乳头状肾细胞癌12个,嫌色细胞性肾癌16个,其他恶性肿瘤7个。透明细胞性肾癌Ⅰ级44例,Ⅱ级44例,Ⅲ级16例,Ⅳ级5例,未分级1例。良性肿瘤的平均ADC值(1.29×10-3mm2/s)低于恶性肿瘤的平均ADC值(1.56×10-3mm2/s)。以良恶性肿瘤ADC值绘制ROC曲线,曲线下面积为0.696。其中透明细胞性肾癌ADC值最高且明显高于其他各组,其次为嗜酸细胞腺瘤,乳头状肾细胞癌,嫌色细胞性肾癌、血管平滑肌脂肪瘤和其他恶性肿瘤组等ADC均值几乎相等。以不同病理类型肿瘤ADC值绘制ROC曲线,针对透明细胞性肾癌与其他病理类型的肿瘤作鉴别。通过计算曲线下面积为0.854,如果以1.355×10-3mm2/s为阈值,诊断透明细胞性肾癌的敏感性利特异性分别为80%和78.5%。不同级别的透明细胞性肾癌ADC值随细胞级别的升高有逐渐下降的趋势。结论：扩散加权成像对不同良恶性、不同病理类型肾脏肿瘤、不同级别的透明细胞性肾癌有一定的鉴别诊断价值,结合常规MR检查能提高诊断效能。正常肾脏的3.OT MR多期动态增强扫描时相研究目的：探讨适用于肾脏磁共振增强扫描正确的扫描时相。材料与方法：对30名肾脏功能正常的病例进行多期动态增强MR扫描。其中男20例,女10例,平均年龄52岁。采用3.OT MR脂肪抑制LAVA序列,对比剂注入前扫描蒙片,于对比剂注入后15s开始增强扫描,此后每隔30秒完成一次扫描,其中15s时为单次屏气连续完成两期扫描,余每次屏气完成一期扫描,单期扫描时间9-10s,单期扫描层数为20-24层,全部共10期。注入对比剂后4分钟完成延迟扫描。使用AW4.4工作站测量并记录主动脉、肾皮质、肾髓质增强扫描前及增强扫描后各期的信号强度,进行比较及统计学分析。结果：主动脉强化最早,在第2期(15秒)即可见较明显强化,于第3期(约25秒)达峰,并于第4期(约45秒)保持达峰状态,在之后逐渐下降。肾皮质在第2期仅可见轻度强化,在第3期明显上升,到第4期达峰,随后呈缓慢轻度下降,肾髓质则强化较晚,在第3期才出现轻度强化,之后缓慢上升,到第6期(约105秒)达峰,此后保持较稳定的强化水平。肾脏皮质和髓质信号差值在第3期和第4期较为明显,从第5期开始皮髓质信号差值减小,至第6期及以后各期皮髓质信号强度差值基本稳定。因此确定第2期为动脉期,第3期为皮髓质早期,第4期为皮髓质晚期,第6期为肾实质期。结论：综上所述,肾脏MR多期增强扫描正确时相包括蒙片、动脉期(第2期)、皮髓质早期(第3期)、皮髓质晚期(第4期)、肾实质期(第6期)和延迟期。目的：探讨多期动态增强扫描对不同良恶性、不同病理类型肾脏肿瘤、不同级别的透明细胞性肾癌的鉴别诊断价值。材料与方法：对157例临床怀疑肾脏肿瘤的患者(161个病灶)术前行3.OT常规MR平扫及多期动态增强MR扫描。其中男性100例,女性57例。所有病例均经手术病理证实。采用3.OT MR脂肪抑制LAVA序列,在对比剂注入前扫描蒙片,于对比剂注入后15s开始增强扫描,此后每隔30秒完成一次扫描,其中15s时为单次屏气连续完成两期扫描,余每次屏气完成一期扫描,单期扫描时间9-10s,单期扫描层数为20-24层,全部共6期。注入对比剂后4分钟完成延迟扫描。使用AW4.4工作站测量并记录肾皮质、肾肿瘤于增强扫描前及增强扫描后各期的信号强度,计算信号增强百分比、肿瘤—皮质增强指数、强化峰值、峰值出现的期别、流出率、强化曲线形态,并进行比较及统计学分析。结果：161个病灶中良性病灶28个,恶性病灶133个。良性病灶包括血管平滑肌脂肪瘤20个,嗜酸细胞腺瘤4个,其它良性肿瘤4个。恶性病灶包括透明细胞性肾癌105个,乳头状肾细胞癌10个,嫌色细胞性肾癌13个,其他恶性肿瘤5个。透明细胞性肾癌Ⅰ级44例,Ⅱ级42例,Ⅲ级14例,Ⅳ级5例。良性肾脏肿瘤的动态增强各期信号增强百分比及肿瘤—皮质增强指数的均值在增强扫描各期均低于恶性肿瘤。但统计学分析表明这些差别无明显统计学意义。不同病理类型肾脏肿瘤的动态增强各期信号增强百分比及肿瘤—皮质增强指数的均值有一定的区别,但也有部分交叉重叠。透明细胞性肾癌在增强扫描各期强化程度均明显高于其他类型肿瘤,嗜酸细胞腺瘤、血管平滑肌脂肪瘤、和嫌色细胞性肾癌的强化水平比较接近,均属于中等程度强化,而乳头状肾细胞癌、其他良性肿瘤以及其他恶性肿瘤的强化水平均属于较低程度的强化。在增强扫描第3期即皮髓质早期这种强化的分组趋势较明显。透明细胞性肾癌、嗜酸细胞腺瘤、血管平滑肌脂肪瘤、和嫌色细胞性肾癌均随扫描时相表现出较明显的“快进—流出”的强化趋势,而乳头状肾细胞癌、其他良性肿瘤以及其他恶性肿瘤则表现出“持续上升”的强化趋势。不同级别的透明细胞癌强化程度的差别无统计学意义。结论：多期动态增强扫描对不同良恶性的肾脏肿瘤和不同病理级别的透明细胞性肾癌不能提供鉴别。但不同病理类型的肾脏肿瘤展现出了不同的强化特征,多期动态增强扫描的特点可将不同病理类型的肾脏肿瘤进行分组,结合MR平扫,可提高诊断的准确性。更多还原

【Abstract】 Part I:Renal tumors:diffusion weighted imaging research at 3. OT Objective:To assess the value of diffusion weighted imaging in di fferentiating between benign from mal ignant renal tumors, differentiating among various pathologic subgroups of renal tumors, and various grade of clear cell carcinoma.Materials and methods:171 (110 men,61 women.) patients with 175 clinical suspected renal masses underwent 3. OT routine MR scan and diffusion weighted MR scan before operation. All patients were histopathologically diagnosed. The b value of DWI sequence was 800s/mm". Apparent diffusion coefficient values of both tumor and renal parenchyma were measured with an AW4.4 workstation and were compared by means of different characters, pathologic subgroups and various grade of clear cell carcinoma.Results:there were 30 benign and 145 malignant renal tumors. Benign tumors included 21 angiomyolipoma,5 oncocytoma and 4 other types, while malignant tumors included 110 clear cell RCC,12 papillary RCC,16 chromophobic RCC, and 7 other types. In the 110 clear cell carcinoma, there were 44 for gradeI,44 for grade II,16 for grade III, and 5 for grand IV,1 unclassified. The mean ADC value of benign tumors (1.29×10-3mm2/s)were lower than that of malignant tumors (1.56X 10-3mm2/s), with the area under the ROC curve 0.696. For the different pathologic subgroups of renal tumors, clear cell RCC showed the significant higher ADC value of 1.70×10-3mm2/s, oncocytoma showed the second higher ADC value of 1.16×10-3mm2/s, papillary RCC, chromophobic RCC, and angiomyolipoma got almost equaled ADC value. To differentiate clear cell RCC from other tumors, a cut value of 1.355×10-3mm2/s should be made (area under the curve were 0.854, and sensitivity were 80%, specificity were 78.5%). The analysis of mean ADC value showed an inverse linear correlation with different grade of clear cell RCC.Conclusion:diffusion weighted imaging is useful in differentiating between benign from malignant renal tumors, differentiating among various pathologic subgroups of renal tumors, and various grade of clear cell carcinoma. And the performance of diagnosis can be improved performed together with conventional MR.Part II:Timing of MR multi-phase contrast enhancement for normal kidney-Objective:To investigate the appropriate timing of MR multi-phase contrast enhancement for normal kidney.Materials and methods:30 patients with normal kidney function underwent MR multi-phase contrast enhancement. There are 20 men,10 women, the mean age was 52. MR imaging was performed with a 3.0T scanner by using fat suppressed breath-hold LAVA sequence. The mask images were obtained before contrast agent injection, and the post contrast acquisitions was first performed at 15s, then every 30s take once. Except for the first acquisitions got 2 phases of images during one breath hold, the rest acquisitions got only 1 phase for one breath hold. Each phase took 9-10s, and gained 20-24 slices, all 10 phases were performed including the mask images. A delayed phase was performed 4 min after injection. The signal intensity of aorta, cortex, and medulla of kidney of multi-phase was measured and recorded with an AW4.4 workstation, and then analyzed with SPSS 13.0 software.Results:the aorta got the earliest enhancement, and had obviously high signal intensity at the 2nd phase (15s), reached the peak at the 3rd phase (25s), and kept the peak value to the 4th phase (45s), then began to reduce.The cortex was slightly enhanced at the 2nd phase, and increased sharply during the 3rd phase, till the 4th phase reached the peak, and then began to reduce. The medulla got the latest enhancement and reached the peak at the 6th phase (105s), and kept the status till the 10th phase. The difference between the cortex and medulla were obvious at 2nd and 3rd phase, and began to reduce at 4th phase, then kept constant from 6th to the 10th phases. Then we established the 2nd phase to be the artery phase, the 3rd phase to be early corticomedullary phase, the 4th phase to be late corticomedullary phase, the 6the phase to be nephrographic phase.Conclusion:the appropriate timing of MR multi-phase contrast enhancement of kidney should the mask phase, artery phase (2nd phase), early corticomedullary phase (3rd phase), late corticomedullary phase (4th phase), nephrographic phase (6th phase), and a delayed phase.Partlll:Renal tumors:multi-phase contrast enhancement research at 3.0T Objective:To assess the value of multi-phase contrast enhancement in differentiating between benign from malignant renal tumors, differentiating among various pathologic subgroups of renal tumors, and various grade of clear cell carcinoma.Materials and methods:157(100 men,57 women) patients with 161 clinical suspected renal masses underwent 3.0T routine plain MR scan and multi-phase contrast enhancement MR scan before operation. All patients were histopathologically diagnosed. MR imaging was performed with a 3.0T scanner by using fat suppressed breath-hold LAVA sequence. The mask images were obtained before contrast agent injection, and the post contrast acquisitions was first performed at 15s, then every 30s take once. Except for the first acquisitions got 2 phases of images during one breath hold, the rest acquisitions got only 1 phase for one breath hold. Each phase took 9-10s, and gained 20-24 slices, all 6 phases were performed including the mask images, a delayed phase was performed 4 min after injection. The signal intensity of renal cortex and tumor of multi-phase was measured and recorded with an AW4.4 workstation, and then signal intensity enhancement percentage, cortex-tumor enhancement ratio, peak enhancement percentage, peak phase, flow-out rate, and shape of enhancement curve were calculated and analyzed with SPSS 13.0 software.Results:there were 28 benign and 133 malignant renal tumors. Benign tumors included 20 angiomyolipomas,4 oncocytomas and 4 other types of benign tumors, while malignant tumors included 100 clear cell RCC,10 papillary RCC,13 chromophobic RCC, and 5 other types of malignant tumors. In the 110 clear cell carcinoma, there were 44 for grade I,42 for grade II,14 for grade III, and 5 for grand IV. The signal intensity enhancement percentage and cortex-tumor enhancement ratio of benign tumors were lower than that of malignant tumors, but these difference did not show any statistical significance. For the different pathologic subgroups of renal tumors, clear cell RCC showed the significant higher signal intensity enhancement percentage and cortex-tumor enhancement ratio; oncocytoma, angiomyolipoma and chromophobic RCC showed a similary lower enhancement degree, and got in the moderate enhancement group; papillary RCC, other types of benign tumors, and other types of malignant tumors showed the lowest enhancement degree. This grouping trend was most obvious at the 3rd phase (early corticomedullary phase). Clear cell RCC, oncocytoma, angiomyolipoma and chromophobic RCC showed a wash-out feature of enhancement curve, and the other types of renal tumors showed a gradually filling feature. The enhancement degree and form of different cell grade of clear cell RCC showed no statistical significance.Conclusion:Multi-phase contrast enhancement is of no use in differentiating between benign from malignant renal tumors, differentiating among various grade of clear cell carcinoma. But different pathologic subgroups of renal tumors did show different enhancement features. By using multi-phase contrast enhancement renal tumors can be classified into groups, and together with other sequence, the performance of diagnosis can be when improved.更多还原