The Study On Magnetic Resonance Multimodal Imaging Of Autoimmune Liver Disease

Background and PurposeAutoimmune liver disease(AILD)is a group of autoimmune liver chronic diseases caused by an abnormal immune function,including autoimmune hepatitis(AIH),primary biliary cholangitis(PBC),primary sestial cholangitis(PSC),IgG4-related cholangitis(IgG4-SC),and overlap syndrome.The diagnosis of AILD is based on laboratory biochemical indicators,immunological examination,imaging and pathology.Magnetic resonance imaging(MRI)has high soft tissue resolution,especially functional magnetic resonance imaging,which is strongly important in the diagnosis of liver disease.In recent years,there have been relevant literature reports on T1 mapping,[or the combination of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid,(Gd-EOB-DTPA),T2 mapping,DKI,liver function grading and laboratory biochemical indexes of liver function,and viral hepatitis is more commonly studied.There have been reports of the Ti relaxation time of T1 mapping and the T2 relaxation time of T2 mapping of viral hepatitis patients related to the classification of fibrosis.The mean diffusivity(MD)and mean kurtosis(MK)of diffusion kurtosis imaging(DKI)are associated with the classification of pathological fibrosis and the classification of hepatitis.At present,there are only a few reports of MRI studies on AILD patients.The study of the Gd-EOB-DTPA and conventional T1 weighted imaging(T1WI)in liver fibrosis of PBC patients found that there was a correlation between the enhancement rate of 5min and 20min and histopathological stage.There was a significant correlation between the T1 value and fibrosis,the inflammation of the hepatic lobule and the inflammation surrounding the portal.T2 relaxation time of AILD patients can predict fibrosis.The study of PBC patients found that the liver extraction scores of the lesion group were reduced by the average of the health group,but did not be graded by Child-Pugh.In this study,T1 mapping(combined with Gd-EOB-DTPA dynamic enhanced scanning),T2 mapping and DK1 multimodal magnetic resonance imaging were further used to comprehensively evaluate the clinical biochemical indicators,liver function grading and pathological results of AILD patients,which is expected to further improve the diagnostic value of magnetic resonance imaging.Materials and Methods1.General information80 patients with AILD confirmed by clinic and pathology(6 males and 74 females,mean age(52.63 ± 11.51)years were included,including 11 cases of AIH,34 cases of PBC and 35 cases of PBC-AIH overlap syndrome.The patients underwent MRI plain scan,dynamic enhancement scan,T1 mapping,T2 mapping and DKI scan within 1 week before biopsy.Laboratory tests were conducted within 1 week before biopsy,mainly including liver function indexes[total bilirubin(TBiL),aspartate aminotransferase(AST),alanine aminotransferase(ALT),glutamyl transferase(GGT),alkaline phosphatase(ALP)and albumin(ALB)],biochemical indexes of liver fibrosis(laminin,type IV collagen,hyaluronic acid,procollagen).A total of 65 cases were examined by pathology.The structures of hepatic lobules(intact group and damaged group),small bile duct structures[lesion group(inflammation,proliferation and destruction),no lesion group],stages of hepatic fibrosis(S0～S4)and hepatitis grades(G0～G3)were observed.Among them,80 cases underwent biochemical examination of liver function in the laboratory[80 cases underwent T1 mapping(Gd-EOB-DTPA)and T2 mapping scanning,and 76 cases underwent DKI scanning].T1 mapping(Gd-EOB-DTPA),T2 mapping and DKI were performed in patients with laboratory fibrosis biochemical indexes(75 cases),Child-Pugh grade(76 cases)and pathological examination(65 cases).2.Magnetic resonance imaging examination and measurementThe Siemens Prisma 3.0T magnetic resonance machine and the body 16 channel coil is used.The subjects underwent routine sequence of liver magnetic resonance,T1 mapping,T2 mapping,DKI and Gd-EOB-DTPA(primovist;Bayer Schering Pharma)dynamic enhanced scanning(0.025ml/kg,rate=1.0ml/s).Two image diagnostic physician with more than 5 years of working experience and good at abdominal image diagnosis will analyze the image and measure the data.All post-processing and measurement are carried out in Siemens Syngo post-processing workstation.After the DKI processing,the apparent diffusion coefficient(ADC),MD and MK parameter diagrams are obtained,and the ADC values,MD values and MK values are measured.T1 relaxation time(T1pre)before enhancement and T1 relaxation time(T1post)after enhancement 5 min were measured in T1 mapping image,and T1 change rate was calculated ΔT1,ΔT1=(T1pre-T1post)/T1pre.T2 relaxation time(T2 values)was measured by T2 mapping image.At the measurement level,the level near the first hilar was selected,and the left outer lobe,left inner lobe,right anterior lobe and right posterior lobe were measured for 4 times respectively,and the average value was taken.3.Statistical methodSPSS 22.0 software was used for statistical analysis.Independent sample t test and non-parametric test were used to compare the differences of quantitative indexes of magnetic resonance multimodal imaging between different liver function grades and different pathological results.The receiver operating characteristic(ROC)curve was drawn,and area under the curve(AUC),critical value,sensitivity and specificity were calculated.Spearman correlation test was used to analyze the quantitative parameters of multimodal magnetic resonance imaging(T1pre,T1post,ΔT1,T2 values,ADC values,MD values,MK values)and biochemical indexes.P<0.05 was statistically significant.Results1.Basic clinical information of AILD patientsThe patients with AILD:55 cases were Child-Pugh A grade and 21 cases were Child-Pugh B/C grade in clinical liver function.30 cases were in fibrosis stage(S)0～1 group,35 cases were in(S)2～4 group,20 cases were in hepatitis grade(G)0～1 group,45 cases were in(G)2～3 group,49 cases were in complete hepatic lobule structure group,16 cases were in destruction group,18 cases were in intrahepatic small bile duct structure lesion group and 47 cases were in no lesion group.2 The correlation analysis between the clinical indexes of patients and the imaging parameters in AILD patients were analyzed1)the correlation between the serum biochemical indexes of patients and the imaging parameters in AILD patients:①The TBil was moderately correlated with T1post values(r=0.574)and ΔT1 values(r=-0.525),weakly correlated with T1pre values(r=0.384)and T2 values(r=0.252)(all P<0.05).②The ALB was moderately correlated with T1ppst values(r=-0.582)and ΔT1 values(r=0.527),weakly correlated with Tipre values(r=-0.311)and MK(r=-0.286)(all P<0.05).③The ALT was weakly correlated with T1post values(r=0.343),ΔT1 values(r=-0.277),T2 values(r=0.230),ADC values(r=-0.325),MK values(r=0.337)(all P<0.05).④ The AST was moderately correlated with T1ppst values(r=0.459)and ADC values(r=-0.404),weakly correlated with T1pre values(r=0.264),ΔT1 values(r=-0.388),T2(r=0.269)and MK values(r=0.361)(all P<0.05).⑤The GGT was weakly correlated with T1post values(r=0.226)and ΔT1 values(r=-0.285)(all P<0.05).⑥The ALP were weakly correlated with T1pre values(r=-0.237),(all P<0.05).⑦ The type IV collagen was moderately correlated with T1post values(r=0.488),ΔT1 values(r=-0.476),weakly correlated with T1pre values(r=0.204),T2 values(r=0.229)(all P<0.05).(8)The hyaluronic acid was weakly correlated with T1pre values(r=0.289),T1post values(r=0.344),ΔT1 values(r=-0.262)(all P<0.05).⑨The procollagen was weakly correlated with MK values(r=0.313)(all P<0.05).In conclusion,the T1post values were moderately correlated with the Type Ⅳcollagen(positive),TBiL(positive),AST(positive),ALB(negative).ΔT1 values were moderate correlation with TBil(negative).Ⅳ collagen(negative),ALB(positive).The ADC values were moderate negative correlation with AST.2)The correlation between the clinical liver function Child-Pugh stage and the imaging parameters in patients with AILD and the value of the diagnosis①There were significant differences between Child-Pugh A stage and B/C stage of liver function in T1post values[(345.08 ± 75.70),433.78(405.49,511.66)](ms),ΔT1 values[60.34(53.85,65.62),51.98(42.65,55.64)](%),ADC values(0.79 ± 0.06,0.76 ± 0.06)(×10-3mm2·s-1)and MK values(0.88 ± 0.08,0.92 ± 0.08)(all P<0.05).② T1post values and ΔT1 values differential diagnosis between Child-Pugh A stage and B/C stage of liver function in patients with AILD in AUC were 0.855 and 0.804 respectively(all P<0.05).The critical values were 395.13ms and 60.72%respectively,the sensitivity was 85.7%and 100.0%respectively,and the specificity was 74.5%and 47.3%respectively.The ROC curves of ADC values and MK values were not statistically significant(P>0.05).③ T1post+ΔT1 differential diagnosis of Child-Pugh A stage and B/C stage of liver function in patients with AILD in AUC was 0.849 and greater than that of ΔT1.The sensitivity was 85.7%,and the specificity was 76.4%.3.Correlation between MRI multimodal imaging parameters and pathology in patients with AILD and its diagnostic value1)Correlation and diagnostic value of multimodal imaging parameters with liver fibrosis stage and hepatitis grade① There were significant differences between S0～S1 and S2～S4 of liver fibrosis stage in T1pre values[834.21(806.99,860.61),(885.01 ± 73.71)](ms),T1post values(328.07 ± 65.01,416.31 ± 86.28)(ms),ΔT1 values[61.86(53.33,66.81)、(53.13±9.95)](%)(all P<0.05).The T1pre values,T1post values,ΔT1 values in AUC of the diagnosis of S0～S1 and S2-S4 hepatic fibrosis were 0.765,0.789 and 0.715(all P<0.05),the critical values were 891.05(ms),339.89(ms)and 62.55%,the sensitivity was 51.4%,88.6%and 80.0%,and the specificity was 96.7%,60.0%and 60.0%,respectively.The AUC of T1pre,T1post values and ΔT1 values combined with S0～S1 and S2～S4 were higher than that of the single diagnosis,and the AUC of Tipre+T1post+ΔT1 was 0.836(P<0.001),the sensitivity was 57.1%,and the specificity was 100.0%.②There were significant differences between G0～G1 and G2-G3 of hepatitis grade in T1post values(334.99 ±58.76),(393.63 ± 93.93)(ms),ΔT1[(61.75(54.79,65.33),55.13(49.73,61.16)](%)(all P<0.05).The AUC of T1post values,ΔT1 values in diagnosis of G0～G1 and G2～G3 hepatitis were 0.698 and 0.666,respectively(all P<0.05).The critical values were 364.31ms and 61.16%,the sensitivity was 73.3%and 62.2%,the specificity was 75.0%and 75.0%.The AUC of the T1post+ΔT1(0.696,P=0.012)was higher than ΔT1 alone.The sensitivity and specificity of T1post+ΔT1 diagnosis were 68.9%and 75.0%,respectively.2)Correlation and diagnostic value of multimodal imaging parameters with hepatic lobule structure and small bile duct lesions① There were significant differences between the complete group and the destruction group in the Tipre values(836.54±61.87),(910.81 ±86.78)(ms),T1post values(350.45±78.03),(452.03±74.27)(ms),ΔT1 values[58.30(53.33,64.76),51.41(44.58,56.81)](%)(all P<0.05).The AUC of the Tipre values,T1post values,ΔT1 values were 0.823 and 0.818 and 0.739(all P<0.05).The critical value was 894.37ms and 351.99ms and 53.40%,the sensitivity was 75.0%and 100.0%and 87.5%,the specificity was 89.8%and 49.0%and 51.0%.T1pre values,T1post values and ΔT1 values combined diagnosis is higher than a single diagnosis.T1pre+ T1post+ΔT1 is the largest in the diagnosis of AUC(0.895).The sensitivity was 81.3%and the specificity was 85.7%.②There was no statistical significance in MRI parameters between the small bile duct lesions and the non-lesion group.(P>0.05).Conclusions1.The quantitative parameters of magnetic resonance multimodal imaging and some of the serum biochemical indexes of AILD patients have certain correlation.2.There is a certain correlation between quantitative parameters of MRI and clinical liver function Child-Pugh classification of patients with AILD.3.MRI quantitative parameters can reflect the liver pathology of patients with AILD to a certain extent.