【作者】 程悦；

【导师】 祁吉； 沈文；

【作者基本信息】 天津医科大学 ， 影像医学与核医学， 2008， 硕士

【摘要】 研究目的:比较肝扩散加权成像中不同b值条件下正常人进食前后肝右前叶及右后叶ADC值的变化,以此来评价血流灌注改变以及不同的测量区域对ADC值的影响;观察不同肝纤维化分级病人ADC值的变化,及与相应病理结果的相关性,评价DWI在肝纤维化分级中的价值;观察不同肝纤维化分级病人CT灌注参数的改变,评价CT灌注成像对肝纤维化的诊断能力,并将结果与第二部分MR扩散加权成像的研究结果做比较研究。研究方法:23例受试者(男性18例,女性5例,平均年龄为36.3岁)于禁食8小时及标准餐后1小时分别行DWI检查,b值选择为200 s/mm~2,500 s/mm~2及700 s/mm~2。分别测量餐前餐后各b值条件下右前叶及右后叶ADC值。对两叶进食前后ADC值进行配对t检验,观察进食对两叶ADC值的影响;对进食前后两叶ADC值进行配对t检验,比较不同饮食状态下两叶ADC值有无差别。对57例肝纤维化病人(其中男性43例,女性14例,平均年龄为38.6岁,肝纤维化S1-S4分别为21例,16例,17例,3例)及23例对照组(男性18例,女性5例,平均年龄为36.3岁)进行DWI(b值为500 s/mm~2)检查,ADC值测量过程中,圆形兴趣区放置于右后叶,直径约为1cm。将测得的不同纤维化分级及炎症分级的ADC值进行单因素方差分析,方差齐且组间差别有统计学意义者,采用SNK-q检验进行方差分析及两两比较;方差不齐且组间差别有统计学意义者,采用Dunnett-t3检验进行方差分析及两两比较。对36例肝纤维化病人(其中男性25例,女性11例,平均年龄为41.5岁)及23例对照组(男性18例,女性5例,平均年龄为36.3岁)进行CT灌注检查,用肝灌注分析软件取得不同肝纤维化分级病人肝实质的灌注参数,包括BF,BV,MTT,HAF,PS。将测得的参数进行单因素方差分析,方差齐且组间差别有统计学意义者,采用SNK-q检验进行方差分析及两两比较;方差不齐且组间差别有统计学意义者,采用Dunnett-t3检验进行方差分析及两两比较。对57例肝纤维化病人的MR扩散加权成像研究结果和36例肝纤维化病人的CT灌注成像研究结果进行比较,通过Medcalc统计软件绘制ROC曲线比较两者对肝纤维化诊断的敏感性和特异性。结果:b值为200 s/mm~2时右前叶及右后叶餐后ADC值均明显增加,差别有统计学意义(P值分别为0.000,0.001);b值为500 s/mm~2及700 s/mm~2时,右前叶餐后ADC值明显增加,差别有统计学意义(P值分别为0.001,0.003),右后叶餐后ADC值的改变无统计学意义(P值分别为0.110,0.076)。餐前各b值条件下右前叶与右后叶ADC值差别无统计学意义(P值分别为0.324,0.163,0.854);餐后各b值条件下右前叶及右后叶ADC值差别均有统计学意义(P值分别为0.030,0.036,0.033)。正常对照组与肝纤维化S1组间ADC值差别无统计学意义,与肝纤维化S2,S3,S4组间差别均有统计学意义(P值均为0.000);肝纤维化S1组与S2,S3,S4组间差别均有统计学意义(P值均为0.000);肝纤维化S2与S3,S4组间差别有统计学意义(P值分别为0.006,0.000);肝纤维化S3与S4组间差别有统计学意义(P值为0.003)。G0组与G2,G3,G4各组间ADC值差别有统计学意义(P值分别为0.001,0.002,0.008),G1组与G2,G3,G4组间ADC值差别有统计学意义(P值分别为0.013,0.010,0.027)。BV、BF、MTT、PS在各组间差别无统计学意义。HAF在正常对照组与纤维化较重组(S3-4组)间差别有统计学意义(P值均为0.004)。两种成像方法的比较研究结果显示,MR扩散加权成像对肝纤维化诊断的敏感性和特异性均高于CT灌注成像,分别为78.9%,82.6%和66.67%,73.91。结论:1.进食后肝血流灌注增加,可引起肝ADC值的改变,以b值200s/mm~2时为著;右前叶受血流灌注影响大于右后叶,因此右后叶是ADC测量时最为可靠的ROI放置位置。2.MR扩散加权成像ADC值肝纤维化程度的加重逐渐降低,并可通过ADC值对肝纤维化进行分级,因此,ADC值对肝纤维化的早期诊断及分级有重要价值。3.CT灌注成像各参数中HAF可将纤维化程度较重组(S3,S4)与对照组相区分,对肝纤维化的诊断有一定价值。4.MR扩散加权成像对肝纤维化诊断的敏感性和特异性均高于CT灌注成像,因此本研究认为MR扩散加权成像是目前肝纤维化早期诊断及分级的最佳检查手段。更多还原

【Abstract】 Objective: according to the change of ADC value in right anterior lobe and right posterior lobe after food in-take, to evaluate the effect of hemodynamic change caused by food in-take and different ROI on hepatic DWI; To observe the changes of the ADC value of patients in different grade of fibrosis, and analyze it’s correlation with pathologic result, and then to evaluate the value of DWI in staging of liver fibrosis; To observe the changes of the CTP parameters of patient in different grade of fibrosis, and analyze it’s correlation with pathologic result, then compare them with the results of DWI research, to evaluate the diagnostic value of DWI and CTP in staging of liver fibrosis.Materials and methods: 23 healthy volunteers (male 18, female 5,averaged age 36.3) underwent DWI examination fasting for 8 hours and 1 hour after taking standard meal, the b values for DWI were 200 s/mm2, 500 s/mm2and 700 s/mm2. The ADC values of right anterior lobe and right posterior lobe under different b value were measured respectively. Paired t test was used to compare the ADC value of fasting and postprandial, and also was used to compare the ADC value of right anterior lobe and right posterior lobe. 57 patients with hepatic fibrosis (male 18,female 5,averaged age 38.6, S1～S4 is 21,16,17,3 respectively ) and 23 control group (male 18, female 5,averaged age 36.3) underwent DWI (b=500 s/mm~2) . The ADC value of different fibrosis stage and different inflammatory stage, the ROI were placed in right posterior lobe, about 1 cm. analysis of variance was used to compare the difference among all the groups. 36 patients with liver fibrosis(male 25,female 11,averaged age 41.5 ) and 23 control group (male 18, female 5,averaged age 36.3) underwent dynamic spiral CTP. CTP parameters including hepatic blood flow(BF), blood volume(BV), hepatic arterial fraction(HAF), mean transit time(MTT), permeability surface(PS) were obtained through liver perfusion analysis software. analysis of variance was used to compare the difference among all the groups, ROC curve was used to analyze the sensitivity and specificity of DWI and CTP.Result: when b value was 200 s/mm2, the postprandial ADC value of right anterior lobe and right posterior lobe both increased obviously (P =0.000, 0.001) ; when b was 500 s/mm~2 and 700 s/mm~2, the postprandial ADC value of right anterior lobe increased obviously (P=0.001, 0.003) , but that of right posterior lobe did not change (P =0.110, 0.076) . When fasting, the difference of ADC value between right anterior lobe and right posterior lobe were not significant (P=0.324, 0.163, 0.854) , but it was significant after food in-take(P=0.030, 0.036, 0.033). The difference of ADC value between control group and S1 group was not significant, that between control group and S2,S3,S4 group was significant (Pe =0.000,0.000,0.000) , that between S2 group and S3 group , S3 group and S4 group , S3 group and S4 group was significant (P =0.006,0.000,0.003) . The difference of ADC value between G0 group and G2,G3,G4 group were significant (P =0.001,0.002,0.008) ,that between G1 group and G2,G3,G4 group were significant (P =0.013,0.010,0.027) ;HAF between control group and S3-4 group were different (P =0.004) , the sensitivity and specificity of DWI and CTP was 78.9%, 82 .6% and 66.67%, 73.91% respectively.Conclusion: The ADC value of right posterior lobe is more precise than right anterior lobe, which is the best location for the measure of ADC value. 500 s/mm~2 is the best b value for the measurement of ADC value in hepatic DWI examination. DWI can reflect the change of liver fibrosis earlier than traditional imaging, S2,S3,S4 group can be distinguished according to the change of ADC value, and ADC value can reflect the degree of inflammation roughly. ADC value can be used as an important index for the early diagnosis of liver fibrosis. HAF can distinguish control group and S3-4 group. DWI is the best examination for the diagnosis and stage of fibrosis.更多还原