【作者】 王锡臻；

【导师】 王滨； 刘作勤；

【作者基本信息】 山东大学 ， 影像医学与核医学， 2009， 博士

【摘要】 研究背景前列腺癌（PCa）的生物学特性个体间存在明显差异,制定个体化的治疗方案对于提高疗效至关重要。肿瘤自主增殖的特性导致组织内产生缺氧、高酸的微环境,肿瘤通过调整基因表达提高低氧耐受力和促进血管生成,血管生成、细胞增殖及组织微观环境之间存在相对动态平衡。MR功能成像能反映肿瘤的代谢、微观水分子运动及血流灌注变化等,为评价PCa生物学行为提供新的视角,明确功能成像与PCa生物学特性之间的关系,是制定个体化治疗方案的信息保证。第一部分MRSI和DWI特征与前列腺癌血管生成、细胞增殖及组织内微环境的相关性研究1.研究目的比较PCa、BPH及正常志愿者¹H-MRSI和DWI特点,分析（Cho+Cr）/Cit比值、ADC值与肿瘤的血管生成、细胞增殖及组织微环境内在关系,了解前列腺癌影像学特征的内涵和分子生物学基础。2.材料与方法前列腺MRSI平HDWI都采用Siemens Sonata 1.5T超导成像仪和腹部相控阵线圈,研究对象为PCa、BPH患者及正常志愿者,应用西门子Leonardo工作站相应的软件进行数据处理。计算PCa、BPH及PZ不同感兴趣区的（Cho+Cr）/Cit比值及ADC值,对获得的组织标本进行常规HE和免疫组化染色,记录BPH和PCa的VEGF、MVD、PCNA、细胞密度及HIF-1α,分析（Cho+Cr）)/Cit比值、ADC值及其与组织病理结果内在关系。3.结果3.1.前列腺不同感兴趣区的MRI/MRSI和DWI特征PZ、BPH和PCa代谢物谱线存在明显差异,其（Cho+Cre）/Cit比值分别为0.32±0.03、0.55±0.04和4.19±0.25,PZ、BPH和PCa的（Cho+Cre）/Cit比值依次升高,三者均值比较差别有统计学意义（P＜0.05）。随b值升高,PZ、BPH和PCa DWI信号变化特点不同,三者的ADC值分别为130.20±26.20×10^-5mm²/s、91.23±12.24×10^-5mm²/s和52.11±10.19×10^-5mm²/s,PCa的ADC值最低,三者差别具有统计学意义（P＜0.05）。（Cho+Cre）/Cit比值较高的前列腺癌ADC值相对较低,两者存在负相关关系（P＜0.05）。3.2.前列腺癌和BPH血管生成、细胞增殖和HIF-1α表达水平比较PCa的血管生成指标（MVD和VEGF）、细胞增殖的指标（细胞密度和PCNA-LI）和HIF-1α表达均明显高于BPH的表达水平（P＜0.05）。前列腺癌MVD、细胞密度、PCNA-LI、HIF-1α和分期相互之间存在正相关关系（P＜0.05）,VEGF与MVD、PCNA-LI及HIF-1α之间的正相关性具有统计学意义（P＜0.05）。3.3.（cho+Cr）/Cit的比值和ADC值与血管生成、细胞增殖和HIF-1α的关系PCa的（Cho+Cre）/Cit比值与MVD、VEGF、细胞密度、PCNA-LI、HIF-1α、Gleason分级和分期存在正相关关系（P＜0.05）。PCa的ADC值与细胞密度、PCNA-LI、MVD及HIF-1α存在负相关性（r=-0.64、-0.44、-0.51、-0.36,P＜0.05）。BPH组（Cho+Cre）/Cit比值、ADC值与MVD、VEGF、细胞密度、PCNA-LI及HIF-1α相关性无统计学意义（P＞0.05）。第二部分前列腺PWI、DTI和BOLD成像研究1.研究目的对研究对象行PWI、DTI和BOLD-fMRI成像研究,评估前列腺不同组织成像的特征和应用价值。2.材料与方法使用GE Echo-speed 1.5T MRI成像仪对49例前列腺癌患者行PWI成像检查。通过GE 4.2高级工作站进行数据处理,采用闭孔内肌灌注指标作为内部参考,得到PCa、BPH和PZ相对灌注指标:rNEI、rMTE、rTTM、rMSD和rBF。分析PZ、BPH和PCa三种ROI的相对灌注指标及其与Gleason分级、分期及PSA的相关性。DTI和BOLD成像都采用Siemens Sonata 1.5T超导成像仪和腹部相控阵线圈,应用西门子Leonardo工作站相应的软件进行数据处理。DTI记录感兴趣区FA值、平均ADC值、e1、e2和e3,绘制相应参数图和纤维示踪图像（DTT）。BOLD成像结合吸入混合气（95°%O₂%5%CO₂）状态下完成,记录时间-信号强度曲线（SI-TC）,计算吸入混合气前后信号强度平均增加率,对比不同感兴趣区的相应成像指标的差异。3.结果3.1.前列腺磁共振灌注成像（PWI）PCa的SI-TC特点为注入对比剂迅速出现较大幅度的倒置峰值,信号强度在对比剂首次通过后迅速上升,但低于对比剂到达前水平。BPH和PZ区的SI-TC下降上升都较缓慢。PZ、BPH和PCa的rNEI分别为1.37±0.88、3.22±2.07和6.44±4.29。PCa的rNEI、rMSD和rBF高于BPH和PZ:BPH的rNEI、rMSD和rBF低于前列腺癌区域而高于正常PZ区（＜0.05）。前列腺癌的rMTE低于BPH和PZ（P＜0.05）。前列腺痛rNEI与PSA水平、Gleason分级及TNM分期存在正相关关系（P＜0.05）;rTTM与Gleason分级、TNM分期存在负相关关系（P＜0.05）。3.2.前列腺磁共振扩散张量成像（DTI）PZ、BPH和PCa的FA值分别为0.16±0.03、0.23±0.04和0.46±0.02,前列腺癌的FA值最大,正常外周带最小,BPH介于两者之间,三者FA值差异具有统计学意义（P＜0.05）。PZ、BPH和PCa的平均ADC值、e1、e2和e3之间都存在明显差异（P＜0.05）。不同感兴趣区三个方向本征向量e1、e2和e3相互之间也存在差异（P＜0.05）。3.3.前列腺磁共振血氧水平依赖功能MRI（BOLD-fMRI）PZ、CZ、BPH和PCa的信号强度都随着第一次吸入混合气曲线不断升高,在吸入空气后信号强度慢慢回到基线,不同感兴趣区的信号上升幅度存在差异。PZ、BPH和PCa吸气后信号增加率分别为7.80±0.06%、12.00±0.13%和5.00±0.03%。正常志愿者CZ的吸气后信号增加率高于PZ（P＜0.05）。BPH的信号增加率高于PCa和PZ（P＜0.05）。4.结论（1）前列腺不同感兴趣组织¹H-MRSI和DWI各有不同特征,PCa（Cho+Cr）/Cit比值与MVD、PCNA、细胞密度及HIF-1α表达水平存在相关性;PCa的ADC值大小与组织的细胞密度、PCNA、MVD及HIF-1α表达存在负相关性,¹H-MRSI与DWI可对PCa的血管生成、细胞增殖及肿瘤微环境进行评估,有助于为前列腺癌治疗、随访提供个体化信息;（2）前列腺癌血管生成（MVD,VEGF）、细胞增殖（PCNA、细胞密度）及HIF-1α存在相关性,进一步证实三者之间存在的相对动态平衡,保持相对平衡对于恶性肿瘤的发生发展起到重要的作用;（3） PWI能较好地反映组织微循环灌注水平,前列腺癌病灶具有特征性表现,结合常规MRI检查能显著提高前列腺癌的检出效率,磁共振灌注相关指标可初步评估前列腺癌的分级、分期;（4）正常前列腺中央腺区和外周带、前列腺癌与前列腺良性组织的FA、ADC、e1、e2、e3存在明显差异,DTI能够有效通过观察微观组织结构的差异,在前列腺疾病诊断随访中有较好的应用前景;（5）吸入混合气状态下对前列腺的BOLD成像具有可行性,时间信号曲线和信号强度平均增加率能够显示前列腺不同组织血氧饱和度变化,BOLD有望用于组织血管成熟度的评估;（6）功能磁共振成像能反映出前列腺疾病分子水平改变,在完整的生理微环境中无创的获得不同个体前列腺疾病的特异性信息,多种磁共振功能成像技术结合,可从不同角度了解前列腺癌分子生物学特性,为前列腺癌诊断、治疗和随访提供信息保证。更多还原

【Abstract】 BackgroundsProstate cancer（PCa） is a biologically heterogeneous disease for which a variety of treatment options are available.To achieve more precise biological characterization of PCa is essential for developing individualized treatment programs and improving the efficacy.Autonomous proliferation of tumor will lead to hypoxic and high-acid micro-environment.The tumor enhances the endurance of the ability to survive the poor micro-environment and promote the angiogenesis by adjusting the relevant gene expression.Therefore,there may be a relatively dynamic balance among angiogenesis, cell proliferation and tissue micro-environment.With the development of imaging techniques,magnetic resonance（MR） with some functional imaging methods which can reflect the cell metabolism,water molecular diffusion,micro-architecture and the blood flow perfusion have been used to evaluate the angiogenesis in vivo.These functional MRI techniques provide new perspectives to evaluate the biological behavior of PCa,which is the information assurance of individualized treatment. PartⅠCorrelative study of MRSI/DWI and angiogenesis,cell proliferation and HIF-lαof prostate cancer1.ObjectiveThe main objective of this part is to analyze the relationships between MRSI/DWI and angiogenesis,proliferation and HIF-1αof prostate cancer,as well as the significance of MRSI/DWI in assessing the biological behavior of prostate cancer. 2.Materials and methodsMRSI and DWI were performed using a 1.5 Tesla superconducting magnetic scanner（Siemens） equipped with a pelvic phased-array multi-coil.Healthy volunteers and patients with prostate cancer or benign prostate hyperplasia were included in this study.All data were transferred to Siemens Leonardo Workstation and regions of interest（ROI） of PCa,benign prostate hyperplasia（BPH）,and peripheral zone（PZ） were drawn by a radiologist.The（Cho+Cr）/Cit ratios and ADC values were calculated.Cellularities of PCa were recorded based on hematoxylin and eosin staining.The microvessel density（MVD）,vascular endothelial growth factor（VEGF）, proliferating cell nuclear antigen（PCNA） and hypoxia inducible factor-1 alpha （HIF-1α） of PCa and BPH were detected by immunohistochemical techniques.The relationships among（Cho+Cr）/Cit ratio,ADC values,angiogenesis,proliferation and HIF-1αwere analyzed.3.Results3.1,The features of PCa and BPH on MRI/MRSI and DWIThe MR spectrum of prostate cancer was different from those of BPH and PZ. The average value of（Cho+Cr）/Cit ratio of PZ,BPH and PCa were 0.32±0.03, 0.55±0.04 and 4.19±0.25.The（Cho+Cr）/Cit ratios of prostate cancer were higher than those of PZ and BPH（P＜0.05）.With the increasing of b value,the signal intensity of PZ,BPH and PCa changed differently fiom each others.The ADC values of PZ,BPH and PCa were 130.20±26.20×10^-5mm²/s,91.23±12.24×10^-5mm²/s and 52.11±10.19×10^-5mm²/s respectively.The ADC values of Pea were lower than those of BPH and PZ（P＜0.05）.The higher（Cho+Cr）/Cit ratio of PCa corresponded to lower ADC values.The （Cho+Cr）/Cit ratio of PCa was correlated negatively with ADC values（P＜0.05）.3.2.Comparative analysis of angiogenesis,proliferation and HIF-1αbetween PCa and BPHThe angiogenesis（VEGF,MVD）,proliferation（PCNA,cellularity） and HIF-1αof PCa were higher than those of BPH（P＜0.05）.The MVD,PCNA,cellularity, HIF-1αand stage of prostate cancer were correlated with each other positively （P＜0.05）.The VEGF was correlated positively with MVD,PCNA,HIF-1α,Gleason grade and stage of prostate cancer were correlated with each other（P＜0.05）.3.3.The relationships between MRSI,DWI and angiogenesis,proliferation and HIF-1αof PCa and BPHThe（Cho+Cr）/Cit ratios of PCa were correlated positively with VEGF,MVD, PCNA,cellularity,HIF-1α,Gleason grade and stage（P＜0.05）.The ADC values of PCa were correlated negatively with cellularity,PCNA,HIF-1α,and MVD（P＜0.05）. No relationships were observed among MRSI,DWI and the biological indexes of BPH（P＞0.05）.PartⅡThe Study of PWI,DTI and BOLD in Prostate1.ObjectiveThe objective of this part is to investigate the features and application value of PZ,BPH and prostate cancer in PWI,DTI and BOLD-fMRI.2.Materials and methodsThe clinic and pathologic information of 49 patients with histologically proven PCa were studied.The examination was performed in the supine position using 1.5T superconductive magnet Echo-speed scanner with intergrated endorectal surface coil and pelvic phased array multi-coil.Perfusion weighted imaging（PWI） was acquired using a modified single shot SE echo planar imaging（EPI） sequence.All of the data were transferred to GE Advanced Workstation 4.2.In order to eliminate the variation of individuals,the indexes of obturator internus were used as internal references.The indexes of PWI were calculated by Functool 2 which included signal intensity-time curve（SI-TC）,relative negative enhancement integral（rNEI）,mean time to enhance （rMTE）,time to minimum（rTTM）,maximum slope of decrease（rMSD） and blood flow（rBF）.DTI and BOLD were performed using a 1.5 Tesla superconducting magnetic scanner（Siemens） equipped with a pelvic phased-array multi-coil.Healthy volunteers and patients with prostate cancer or benign prostate hyperplasia were included in this study.BOLD data were acquired during 5×2minute episodes alternating between air and carbogen（95%O₂/5%CO₂） breathing.All data were transferred to Siemens Leonardo Workstation and different regions of interest（ROI） of PCa,BPH,and PZ were drawn by a radiologist.Using the DTI card,the FA,mean ADC values,el,e2 and e3 of DTI were calculated and the corresponding index maps were produced.The SI-TC and percentage of signal increase were recorded.3.Results3.1.Perfusion Weighted Imaging MR（PWI） of PZ,BPH and PCaThe SI-TC of PCa showed rapid and steep inverted peak after the injection of contrast.The signal intensity increased quickly after the firs-pass of contrast with the signal intensity lower than that of before contrast’s arrival.The rNEI of PZ,BPH and PCa were 1.37±0.88,3.22±2.07 and 6.44±4.29.The rNEI,rTTM and rMSD of prostate cancer were higher than those of BPH and PZ（P＜0.05）,while the MTE and TTM of prostate cancer were shorter than those of normal PZ and BPH（P＜0.05）. Positive correlation was found between rNEI and Gleason grade,TNM and PSA level （P＜0.05）.There was a negative correlation between rTTM and Gleason grade,TNM of prostate cancer（r=-0.46;-0.51,P＜0.05）.3.2.Diffusion Tensor Imaging MR（DTI） of PZ,BPH and PCaThe tractional anisotropy（FA） of PZ,BPH and PCa were 0.16±0.03,0.23±0.04 and 0.46±0.02.The FA of prostate cancer were higher than those of BPH and PZ （P＜0.05）.The ADC values,e1,e2 and e3 of PZ,BPH and PCa were different from each others（P＜0.05）.Obvious differences among e1,e2 and e3 were observed （P＜0.05）.3.3.Blood oxygen level-dependent（BOLD） MR of PZ,BPH and PCaThe SI-TC showed obvious enhancement during carbogen breathing.The signal intensity returned to baseline during the following period of normal air breathing.A repeated but less sharp signal changes were observed during the second period of carbogen breathing.The increasing rate of SI PZ,BPH and PCa were 7.80±0.06, 12.00±0.13 and 5.00±0.03,respectively.The increasing rate of SI of normal central gland was higher than that of peripheral zone（P＜0.05）.The increasing rate of SI of BPH were higher than those of PZ and PCa（P＜0.05）.4.Conclusion（1）.The ROIs of PZ,BPH and PCa have the different characteristics respectively on MRSI and DWI.The（Cho+Cr）/Cit ratios of PCa were correlated positively with VEGF,MVD,PCNA,cellularity,Gleason grade and stage.The ADC values of PCa were correlated negatively with cellularity,PCNA and MVD.Therefore,¹H-MRSI and DWI are helpful to predict the variables of angiogenesis,proliferation and microenvironment of prostate cancer.（2）.The correlation among angiogenesis, proliferation and microenvironment demonstrate that there is a dynamic balance between the biological features of prostate cancer.This dynamic balance is crucial to the development of prostate cancer.（3）.PWI can reflect the difference in microcirculation between PCa and benign tissues.Combined with conventional MRI, PWI is helpful to detect lesions.According to the correlation between indexes of PWI and clinicopathological results of prostate cancer,PWI can be used to evaluate the biological features.（4）.The FA,ADC,e1,e2 and e3 acquired from DTI can used to evaluate the three-dimensional architecture of PZ,BPH and PCa.The DTI and DTT have the potential to evaluate the micro-structural changes of prostatic diseases. （5）.BOLD-fMRI during carbogen breathing is feasible.Its signal changes can be distinguished clearly between prostate cancer and contrlateral normat prostate tissue, which contributes to the diagnosis of early prostate cancer.According to the BOLD-fMRI,the function and maturity of micro-vascular may be evaluated.（6）Every functional MR technique is provided with their own advantages.Multiple functional magnetic resonance technologies can reflect the molecular level changes from different prospectives and assess the individualized biological characteristics of prostate cancer non-invasively.So,combining multi-methods together may offer more information for clinical diagnosis and therapy.更多还原