| Part one.The value of 3.0T MR-DKI quantitative parameters histogram analysis in distinguishing mucinous adenocarcinoma from common adenocarcinomaObjective:To explore the value of quantitative parameter histogram analysis of 3.0T MRI diffusion kurtosis imaging(DKI)in the differential diagnosis of mucinous adenocarcinoma(MC)and adenocarcinoma(AC)of rectum,and to compare the diagnostic efficiency with that of traditional diffusion weighted imaging(DWI).Materials and methods:The imaging and clinicopathological data of 110 patients with rectal adenocarcinoma confirmed by surgery and pathology from September 2015 to September 2019 in the Second Affiliated Hospital of Soochow University,who were examined by routine MRI and DKI with multiple b values(b values range from 0 to 2000s/mm2),were analyzed retrospectively,including 16 cases were in MC and 94 cases were in AC.In all cases,the software of firevoxel was used for image post-processing,combined with high-definition(HR)T2WI image,the region of interest(ROI)was manually drawn layer by layer along the edge of the tumor on the DKI image with b=1000s/mm2,and the three-dimensional ROI of the tumor was obtained after multi-layer fusion.The quantitative parameters of DKI,including the diffusion coefficient(D)value corrected by non Gaussian distribution,were measured,kurtosis constant(K)value,and the apparent diffusion coefficient(ADC)value of DWI quantitative parameters were obtained by image registration.Histogram analysis was carried out by MATLAB2018b and SPSS25.0 software,and the average,median,25th,75th,skewness and kurtosis of D,K and ADC values were obtained respectively.Two groups of independent samples t test or Mann Whitney U test were used to evaluate the difference of quantitative histogram parameters of DKI and DWI between rectal MC and AC,binary logistic regression was used to conduct multivariate analysis to find out the main indicators and multivariate comprehensive analysis indicators and receiver operating characteristic(ROC)curve was used to evaluate the effectiveness of quantitative histogram parameters related to histopathological classification in differential diagnosis of rectal MC and AC.The difference of AUC was compared by Delong method.Result:Among 110 patients with rectal adenocarcinoma,16 cases were in MC,10 cases were males and 6 cases were females,with an average age of 59.44 ± 12.56 years.Among them,1 cases was in the upper segment of rectum,11 cases in the middle segment and 4 cases in the lower segment;0 patient in pT1 stage,3 patients in pT2 stage,10 patients in pT3 stage and 3 patients in pT4 stage;8 patients in pN0 stage(without lymph node metastasis)and 8 patients in PN+stage(with lymph node metastasis),4 patients in PN1 stage and 4 patients in pN2 stage.There were 94 cases in AC,53 cases were males and 41 cases were females,with an average age of 64.04±11.36 years,including 23 cases in the upper rectum,44 cases in the middle rectum and 27 cases in the lower rectum;12 patients in pTl,25 patients in pT2,48 patients in pT3 and 9 patients in pT4;60 patients in pN0,34 patients in PN+ phase,13 patients in PN1 and 21 patients in pN2 phase;.There was no significant difference in gender,age,focus location,T stageand N stage between MC and AC(P>0.05).The statistical results showed that in the quantitative parameters of DKI,D(mean,median,75th)of tumor parenchyma in MC was higher than that in AC(P<0.05),D(skewness and kurtosis)was lower than that in AC(P<0.05),K(mean,median,25th,75th)was significantly higher than that in AC(P<0.001);there was no difference in D(25th)and K(skewness and kurtosis)between MC and AC Statistical significance(P>0.05).The AUC of K(median)is the largest,which is 0.825.The critical value is 0.885 when yoden index is the largest,and the sensitivity and specificity are 77.7%and 81.2%respectively.The AUC of D(75th)is larger,which is 0.785.The critical value is 1.919×10-3mm2/s when yoden index is the largest,which is 75.0%and 76.5%respectively.In DWI quantitative parameters,ADC(mean,median,25th and 75th)of tumor parenchyma in MC was significantly higher than that in AC(P<0.05);ADC(skewness and kurtosis)was lower than that in AC,but the difference was not statistically significant(P>0.05).The AUC of ADC(75th)is the largest,which is 0.784.The critical value is 1.247×10-3mm2/s when the Jordan index is the largest.The sensitivity and specificity of ADC are 81.3%and 73.4%respectively.According to the multivariate binary logistic stepwise regression screening,D median and K25%were significant(B were 2966.166 and-4.550;Wals were 9.000 and 15.720;P were 0.003 and<0.001).The combined AUC was 0.85,but there was no significant difference between them.The results of histogram analysis of quantitative parameters of DKI and DWI measured by two physicians were in good agreement,and the range of intra group correlation coefficient(ICC)was 0.880-0.981.Conclusion:The quantitative parameter histogram analysis of DKI is helpful for the differentiation of rectal MC and AC,among which D median and K25%are of differential diagnostic significance,and superior to ADC of DWI.Part two.The application value of 3.0T MR-DKI quantitative parameters histogram analysis in staging and pathological grading of rectal adenocarcinomaObjective:To explore the correlation between the quantitative parameter histogram analysis results of diffusion kurtosis imaging(DKI)and diffusion weighted imaging(DWI)and the stage and pathological grade(degree of differentiation)of rectal common adenocarcinoma(AC),and to further explore the application value of the quantitative parameter histogram analysis results in the differentiation of T2 and T3 rectal AC.Materials and methods:The imaging and clinicopathological data of 94 patients with rectal AC confirmed by surgery and pathology from September 2015 to September 2019 in the Second Affiliated Hospital of Soochow University,who were examined by conventional MRI and multiple b values(b values range from 0 to 2000s/mm2)DKI,were analyzed retrospectively,including 12 cases of pT1,24 cases of pT2,48 cases of pT3 and 9 cases of pT4.All cases were analyzed by the software of firevoxel,combined with HR-T2WI image,the region of interest(ROI)was manually delineated layer by layer along the tumor edge on DKI image with b value of 1000s/mm2,the three-dimensional ROI of tumor was obtained after multi-layer fusion.The quantitative parameters of DKI were measured,including diffusion coefficient(D)value and kurtosis coefficient(K)value corrected by non Gaussian distribution.The apparent diffusion coefficient(ADC)value of DWI quantitative parameters was obtained by image registration.The histogram analysis was carried out by MATLAB2018b and SPSS25.0,and the average,median and 25th,75th,skewness and kurtosis of D,K and ADC values were obtained respectively.Patients were divided into early group(T1-2 stage)and late group(T3-4 stage)according to whether the tumor broke through the rectum proper muscle layer,and further divided into T2 stage and T3 stage.Spearman rank correlation analysis was used to evaluate the correlation between the results of histogram analysis of quantitative parameters and the local T staging of rectal AC,and ROC curve was used to evaluate the effectiveness of histogram quantitative parameters in the differential diagnosis of T2 and T3 rectal adenocarcinoma.Mann Whitney U test was used to evaluate the difference of quantitative histogram parameters of rectal AC with different pathological grades.The difference of AUC was compared by Delong method.Result:Among the 94 patients with rectal AC,53 patients were male and 41 patients were female,with an average age of 64.04±11.36 years,including 23 cases in the upper rectum,44 cases in the middle rectum and 27 cases in the lower rectum;12 patients in pT1,25 patients in pT2,48 patients in pT3 and 9 patients in pT4;60 patients in pNO,34 patients in PN+phase,13 patients in PN1 and 21 patients in pN2 phase.In the early group(T1-2 stage),there were 12 males and 13 females with an average age of 64.56±11.36 years,including 2 cases in the upper rectum,14 cases in the middle rectum and 9 cases in the lower rectum;19 cases in pN0 stage,6 cases in PN+stage,including 3 cases in PN1 stage and 3 cases in pN2 stage.In the late stage group(T3-4 stage),there were 12 males and 13 females with an average age of 64.56 ± 11.36 years,including 2 cases in the upper part of the rectum,14 cases in the middle part and 9 cases in the lower part;19 cases in pN0 stage,6 cases in PN+stage,including 3 cases in PN1 stage and 3 cases in pN2 stage.The statistical results showed that in the quantitative parameters of DKI,the D(mean,median,25th,75th)and K(skewness)of tumors in the early group were higher than those in the late group;the D(skewness and kurtosis)and K(median,25th,75th)of tumors in the early group were lower than those in the late group,and the differences were statistically significant(P<0.05);the K(mean and kurtosis)of tumors in the early group and the late group were not statistically significant(P<0.05)The significance of planning.D(mean,median,75th)and K(skewness)were negatively correlated with T2 and T3 rectal AC stages(r range from-0.332 to-0.266,P<0.05),D(kurtosis)and K(median,25th)were positively correlated with T2 and T3 rectal AC stages(r range from-0.244 to-0.284,P<0.05),and D(25th,skewness)was not significantly different between T2 and T3 rectal AC stages.The AUC under ROC of K(skewness)is the largest,which is 0.727.The critical value is-0.629 when yoden index is the largest.Its sensitivity and specificity are 84.0%and 60.4%respectively.In DWI quantitative parameters,ADC(mean,median,25th and 75th)in early group was significantly higher than that in late group(P<0.05),and ADC(skewness and kurtosis)was lower than that in AC group(P<0.05).ADC(mean,median,75th)was negatively correlated with T2 and T3 rectal AC stages(r value was-0.342?-0.285,P<0.05);ADC(25th,skewness and kurtosis)had no significant difference between T2 and T3 rectal AC stages.The AUC of ADC(75th)is the largest,which is 0.708.The critical value is 1.222×10-3mm2/s when the Jordan index is the largest.Its sensitivity and specificity are 52.0%and 85.4%,respectively.There was no significant difference in AUC between K(skewness),D(75th)and ADC(75th)by Delong method(Z value was 0.330,0.242,0.146,P value was 0.741,0.808,0.884,respectively).There was no significant difference between the quantitative histogram parameters of DKI and DWI in different pathological grades of AC(P>0.05).Conclusion:DKI quantitative histogram parameters are correlated with local T-staging of rectal AC,among them,D(75th),K(skewness)and ADC(75th)are more effective in distinguish T2 and T3 rectal AC,but the practical application value of each parameter in predicting rectal AC pathological grading needs further study. |
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