Functional Magnetic Resonance Imaging For The Study Of Intestinal Crohn's Disease

Purpose:To identify inflammatory and fibrotic mural stricture in Crohn’s disease(CD)using MRI difffusion-weighted Imaging(DWI)and to compare DWI findings with those of enteroscope and histological markers.Method and Materials:Thirty-one patients with CD(18 males,13 females;mean age,38.9 years)were recruited in this approved retrospective study and an informed consent was obtained from each subject.All subjects underwent bowel MRI examination with conventional and DWI sequences at 3.0 T.Colonoscopy results were distributed within 24 hours after examination.According to the endoscopic manifestations and pathological results,the patients were divided into two groups:inflammatory(21/31)and fibrotic(10/31).Results:In the group of inflammatory stricture,the mean ADC value of stricture bowel was 1.4 ± 0.23 × 10-3mm2/s,whereas 0.8 ±0.16 ×10-3 mm2/s in the group of fibrotic stricture.Inter-group independent sample t-test was performed.A statistically significant difference was observed(t = 7.403,P<0.001).The area under receiver-operating characteristic curve was 0.981(95%confidence interval,0.943-1.000),with 1.11×10-3mm2/s as the cut-off point.The sensitivity of low ADC values in detecting inflammatory bowels was 90.5%,and the specificity of high ADC values in excluding inflammatory bowels was 100%.Conclusion:Decreased ADC values in inflammatory stricture bowel may be resulted from multiple factors,including an increase in cellularity,presence of edema,micro-abscesses and increased perfusion.Meanwhile,fibrotic tissue deposition was indicated to lead to restrictions in diffusion.Distinguishable ADCs were observed between inflammatory and fibrotic bowel stricture,where DWI sequence could contribute to the identification.Objective:The purpose of this study was to evaluate permeability parameters such as volume transfer constant(Ktrans),extravascular extracellular space volume fraction(Ve)9 reflux constant(Kep),blood plasma volume(Vp),and apparent diffusion coefficient(ADC)value in Crohn’s disease(CD).Method and Materials:Thirty patients with CD(21 males,9 females;mean age,31.00 ± 13.83 years)were recruited in this approved prospective studies and the informed consent was obtained from each subject.All subjects underwent bowel MRI examination with conventional,Dynamic contrast-enhanced(DCE)and Diffusion-weighted(DW)sequences.Region of interest(ROI)for permeability parameters was drawn at the area of maximal enhancing solid portion of the intestinal wall,which was considered the most serious inflammation.ADC value was measured at the same ROI as DCE-MRI.The relation between two kinds of functional imaging parameters was evaluated.Results:The mean Ktrans value of stricture bowel was 1.16 ± 0.77 min-1,Kep value was 1.71± 0.88 min-1,Ve value was 0.87 ± 0.42,and Vp value was 0.080 ± 0.18,whereas 1.42 ± 0.32×10-3 mm2/s in ADC.The correlation coefficient between ktrans and ADC was-0.396,p = 0.030<0.05.The correlation coefficient between Ve and ADC was-0.507,p = 0.004<0.05.Conclusions:The pathological changes of intestinal Crohn’s disease including microcirculation and the micro environment.Functional magnetic resonance imaging can display the changes of perfusion,vascular permeability,angiogenesis,and extracellular space in the lesion intestinal of CD.Quantitative parameters were contributed to statistical analysis.Purpose:To investigate diagnosis efficacy of dynamic contrast-enhanced MRI(DCE-MRI)and diffusion-weighted MRI(DW-MRI)in Crohn’s Disease(CD).To find out the correlations between functional MRI parameters including Ktrans,Kep,Ve,Vp,and apparent diffusion coefficient(ADC)with serologic biomarker.The relationships between pharmacokinetic parameters and ADC were also studied.Method and Materials:Thirty two patients with CD(22 males,10 females;mean age:30.5 years)and eighteen healthy volunteers without any inflammatory disease(10 males,8 females;mean age,34.11 years)were enrolled into this approved prospective study.Pearson analysis was used to evaluate the correlation between Ktrans,Kep,Ve,Vp,and C-reactive protein(CRP),ADC and CRP respectively.The diagnostic efficacy of the functional MRI parameters in terms of sensitivity and specificity were analyzed by receiver operating characteristic(ROC)curve analyses.Optimal cut-off values of each functional MRI parameters for differentiation of inflammatory from normal bowel were determined according to the Youden criterion.Results:Mean value of Ktrans in CD group was significantly higher than that of normal control group.Similar results were observed for Kep and Ve.On the contrary,ADC value was lower in CD group than that in control group.Kreans and Ve were shown to be correlated with CRP(r = 0.725,p<0.001;r = 0.533,p = 0.002),meanwhile ADC showed negative correlation with CRP(r =-0.630,p<0.001).There were negative correlations between the pharmacokinetic parameters and ADC,such as Ktrans to ADC(r =-0.856,p<0.001),and Ve to ADC(r =-0.451,p = 0.01).The area under the curve(AUC)was 0.994 for Ktrans(p<0.001),0.905 for ADC(p<0.001),0.806 for Ve(p<0.001),and 0.764 for Kep(p = 0.002).The cut-off point of the Ktrans was found to be 0.931 min-1.This value provided the best trade-off between sensitivity(93.8%)and specificity(100%).The best cut-off point of ADC was 1.11 × 10-3mm2/s.At this level,sensitivity was 100%and specificity was 68.8%.Conclusions:DCE-MRI and DW-MRI were helpful in the diagnosis of CD.Quantitative MRI parameters could be used to assess the severity of inflammation.The relationships between pharmacokinetic parameters(Kytans and Ve)and ADC reflected microstructure and microcirculation of CD to some extent.Objective:To assess the severity of crohn’s disease(CD)using quantitative parameters of MRI including apparent diffusion coefficient(ADC)and volume transfer constant(Ktrans).Method and Materials:Fifty patients(29 males,21 females;mean age,28.00 ±13.83years)with CD(only one lesion,and located in the ileocecal)were recruited in this prospective studies.All subjects underwent bowel MRI examination with Conventional,Diffusion-weighted(DW)and Dynamic contrast-enhanced(DCE)sequences.Each subject’s quantitative parameters of MRI(ADC,Kytrans)and clinical data[Harvey-Bradshow index(HBI),C-reactive protein(CRP)]were collected.(1)According HBI,all CD patients were divided into three groups such as severe group,mild-moderate group,and static group.One-way ANOVA was used to compare values of Ktrans and ADC among the three groups.(2)Pearson analysis was used to evaluate the correlation between quantitative parameters of MRI and clinical data.Results:(1)There was significant difference of mean ADC value between the static group and the mild-moderate group(p = 0.031),also the difference of Ktrans was found(p<0.001).The difference were significant in both Kytrans and ADC between the static group and the severe group(p<0.001,p<0.001).Similar results were observed between the mild-moderate and the severe group(p<0.001,p= 0.041).(2)The correlation coefficient between Ktrans and HBI was 0.635(p<0.001).The correlation coefficient between Ktrans and CPR was 0.764(p<0.001).Meanwhile ADC showed negative correlation with HBI(r =-0.614,p<0.001)and CRP(r =-0.490,p<0.001).There was negative correlation between the pharmacokinetic parameters(Ktrans)and ADC(r =-0.348,p = 0.013).The correlation between HBI and CRP was positive(r = 0.755,p<0.001).Conclusions:Quantitative parameters of MR including Ktrans and ADC were contributed to assess the severity of CD.ktrans as pharmacokinetic parameter was more sensitive in assessing CD activity.