【作者】 周洁；

【导师】 罗良平；

【作者基本信息】 暨南大学 ， 影像医学与核医学， 2011， 硕士

【摘要】 目的：探讨磁共振弥散张量成像(diffusion tensor imaging, DTI)对前列腺癌(prostate carcinoma, PCa)和良性前列腺增生(benign prostate hyperplasia, BPH)的诊断及鉴别诊断价值。资料与方法：分别对22例PCa和31例BPH患者及20名健康志愿者的前列腺进行常规MRI、动态增强MRI及DTI扫描,通过常规MRI及动态增强MRI图像对所有病例做出影像学诊断并在AW4.2后处理工作站进行DTI数据处理,分析PCa癌灶、BPH增生结节,正常中央带及外周带的各向异性值(fractional anisotropy,FA值)和平均表观弥散系数(apparent diffusion coefficient,ADC值)的统计学差异及不同b值时(b=500 s/mm2及b=800s/mm2)各观察组FA值及ADC值的变化特点,评价DTI对PCa的诊断价值及常规MRI、动态增强MRI、DTI三者相联合对PCa的诊断价值。结果：(1)]PCa. BPH.正常中央带及外周带的FA值依次降低,四者有显著统计学差异(当b=500 s/mm2时,F=105.87,P=0.000；当b=800 s/mm2时,F=296.769,P=0.000);PCa、BPH、正常中央带及正常外周带的ADC值依次增高,差异有统计学意义(当b=500 s/mm2时,F=47.288,P=0.000；当b=800 s/mm2时,F=66.331,P=0.000)。(2)各观察组的FA值及ADC值均随b值的增大而减小。(3)当b=800 s/mm2时,将PCa组织FA值的95%可信区间的下界0.387定为临界值,以此为标准诊断PCa的敏感度、特异度分别为63.64%、100%,Youden指数为0.64;将PCa组织ADC值的95%可信区间的上界1.143×10-3mm2/s定为临界值,以此为标准诊断PCa的敏感度、特异度分别为59.09%、100%,Youden指数为0.59。(4)常规MRI联合动态增强MRI诊断PCa的敏感度为95.45%,特异度为77.42%；常规MRI、动态增强MRI、DTI三者相联合诊断PCa的敏感度及特异度为86.36%、93.55%,Youden:指数为0.80。结论：(1)利用GE 1.5T Signa HD磁共振扫描仪进行前列腺DTI扫描,当b=800s/mm2时,可以获得高质量的DTI图像,各观察组的FA值及ADC值较稳定。(2)PCa、BPH、正常中央带及外周带的FA值依次降低而ADC值依次增高,组间有显著统计学差异,有助于前列腺疾病的诊断及鉴别诊断。(3)单独应用DTI诊断PCa的价值不大(以FA值=0.387或ADC值=1.143×10-3 mm2/s为诊断阈值),Youden:指数<0.70。(4)常规MRI、动态增强MRI结合DTI成像诊断PCa有较高的诊断价值(Youden指数为0.80)。更多还原

【Abstract】 Objective:To investigate the value of DTI in diagnosis and differential diagnosis of prostate cancer (PCa) and benign prostatic hyperplasia (BPH).Materials and Methods:22 cases of PCa,31 BPH patients and 20 healthy volunteers were scanned in prostate conventional MRI, dynamic contrast-enhanced MRI and DTI. Imaging diagnosis were made in all cases by conventional MRI and dynamic contrast enhanced MRI images, then all data of DTI were transfered to the AW 4.2 workstation for processing. The changes of fractional anisotropy (FA) and average apparent diffusion coefficient (ADC) of PCa foci, BPH nodules, normal central zone and peripheral zone were analyzed. The value of DTI in prostate cancer diagnosis was evaluated.The value of conventional MRI joint with dynamic contrast-enhanced MRI and DTI in PCa diagnosis was evaluated at the same time.Results:(1)The FA values of PCa, BPH, normal central zone and peripheral zone were decreased in turn, and there is statistical difference among the four observation groups(when b= 500 s/mm2, F= 105.87, P= 0.000; when b= 800 s/mm2, F= 296.769, P= 0.000). The ADC values of PCa, BPH, normal central zone and peripheral zone were increased in turn, and there is statistical difference among the four observation groups(when b= 500 s/mm2, F=47.288, P=0.000; when b=800 s/mm2, F=66.331, P=0.000).(2)FA and ADC values among the observation groups were reduced with the b value increased. (3) When b= 800s/mm2, the sensitivity and specificity of FA for the diagnosis of PCa were 63.64% and 100% if the lower bound of 95% confidence interval was set as a differential level, Youden index was 0.64; the sensitivity and specificity of FA for the diagnosis of PCa were 59.09% and 100% if the upper bound of 95% confidence interval was set as a differential level, Youden index was 0.59. (4)The sensitivity and specificity of conventional MRI combined with dynamic contrast-enhanced MRI in the diagnosis of PCa were 95.45% and 77.42%, but the sensitivity and specificity were 86.36%,93.55% when conventional MRI joint with dynamic contrast-enhanced MRI and DTI (FA value or ADC values) in the diagnosis of PCa. Conclusion:(1)Using GE 1.5T Signa HD MR scanner for prostate DTI scan, when the b value = 800s/mm2, we can obtain high quality DTI images. The FA values and ADC values of the four observation groups were stable. (2)The FA values of PCa, BPH, normal central zone and peripheral zone were decreased in turn,but the ADC values were increased in turn.The FA values and ADC values of different prostate tissue provided by DTI were significantly different, and were valuable for prostate disease diagnosis and differential diagnosis. (3)There was low diagnostic value in the diagnosis of PCa by DTI alone.(4)There was high diagnostic value in the diagnosis of PCa by conventional MRI combined with DTI and dynamic contrast-enhanced MRI,(Youden index was 0.80). (5)DTI can show fiber characteristics within the different prostate tissue, but it needs further study to prove the value that DTI showed fiber bundles within different prostate tissue.更多还原