A Relationship Study Between DCE-MRI Parameters And Pathological Staging And Grading In Rectal Cancer

Objective:To explore the correlation between 3.0T DCE-MRI parameters and pathological stage and grade of rectal cancer,and to provide more useful information for clinical improvement of preoperative diagnosis and prognosis of rectal cancer.Materials and Methods:Subject:There were 68 patients in March 2015 to April 2016 in our hospital confirmed by biopsy pathology as rectal cancer.All of the patients took preoperative MRI examination in two weeks and confirmed by surgical pathology for different degrees of differentiation and different pathology.There were 48 males and 20 females with an average age of 56.15±11.57（range27-79）.Pathological diagnosis based on the American Cancer Joint Committee Colorectal Cancer 2010 7th edition TNM staging criteria.Study methods:Siemens Magnetom Verio 3.0T superconducting magnetic resonance scanner,8-channel body phased-array coil and Siemens 3.0T MRI workstation 4D Tissue software.All patients underwent pelvic transverse axial T1WI,T2WI,transverse axial T2WI fat suppression sequence,rectal high resolution T1WI,T2WI transverse axis,crown,sagittal and DWI sequence,dynamic enhanced scan.Measure the K^trans,Kep,and Ve values on the postprocessing station and plot the signal intensity-time curve.All lesions were surgically removed.Study project:According to pathological criteria make pathological grading,pathological staging;Description of rectal cancer MRI morphology and hemodynamic performance;Compare the differentce between K^trans,Kep,Ve,of rectal cancer in different pathological stages and grading groups;Study the correlation of pathological stages and grading and those parameters of DCE-MRI.Statistical analysis:SPSS17.0 statistical software were used to analyze all data.Metrological data was shown as（mean±standard deviation）,and P<0.05statistically indicated the difference significantly.The variance homogeneity analysis was performed by Levene method,and then the K^trans,Kep and Ve values were compared between different pathological stages and grading groups using single factor analysis of variance.The correlation ofK^trans,Kep and Ve values was analyzed by spearman correlation.The ROC curve was used to analyze the critical values of the K^transrans and Ve value for pathological grading and staging.Results:Pathological findings:1,pathological type and grade:68 cases of postoperative pathologywereconfirmedrectaladenocarcinoma:includingtubular adenocarcinoma 66.2%（45/68）,papillary adenocarcinoma 7.3%（5/68）,mucinous adenocarcinoma 2.9%（2/68）,tubular-papillary adenocarcinoma 19.1%（13/68）,tubular-mucinous adenocarcinoma was 2.9%（2/68）,Signet ring cell carcinoma,1.2%（1/68）;well differentiated was 20.6%（14/68）,moderate differentiation was66.2（45/68）,poorly differentiated was 13.2%（9/68）.2,pathological stage:pathological T stage:T1² stage was 39.7%（27/68）,T3 was 42.6.2%（29/68）,T4 stage was 17.6%（12/68）;pathological N staging:38 cases in N0,16 cases in N1,14cases in N2;46 cases in the largest diameter of tumor of 5cm,22 cases in diameter≥5cm.MRI performance:1,morphological manifestations:9 cases of rectal cancer located in upper rectum,9 cases in the middle,18 cases in the mid-low,23 cases in the mid-upper,9 cases in the low;2,hemodynamic performance:（1）typeⅠ（platform type）TIC was 26.5%（18/68）,type II（outflow type）TIC was 63.2%（43/68）,typeⅢ（inflow type）TIC was10.3%（7/68）.（2）The mean K^trans:（1）0.776±0.218min^-11 in well differentiated grade 1,0.812±0.205min^-11 in grade 2,1.009±0.225min^-11 in grade 3;（2）0.719±0.131min^-1in T1²stage,0.874±0.232 min^-11 in T3 stage,0.978±0.238 min^-11 in T4 stage;（3）0.801±0.217min^-1inN0stage,0.832±0.184min^-1inN1stage,0.911±0.255min^-1in N2 stage;（4）0.814±0.221min^-11 in tumor diameter<5cm,0.866±0.217min^-11 in diameter≥5cm group.（3）ThemeanKep:（1）1.434±0.404min-1inwelldifferentiatedgrade1,1.298±0.414min^-1ingrade2,1.708±0.443min^-1ingrade 3;（2）1.337±0.39min^-11 in T1² stage,1.369±0.468min^-11 in T3 stage,1.505±0.433min^-1in T4 stage,（3）1.382±0.407min^-11 in N0 stage,1.304±0.402min^-11 in N1stage,1.462±0.542min^-11 in N2 stage（4）1.305±0.402min^-11 in tumor diameter<5cm group,1.537±0.462min^-11 in diameter≥5cm group.（4）The mean Ve:（1）0.591±0.095 in well differentiated grade 1,0.686±0.094 in grade 2,0.621±0.123 in grade 3;（2）0.631±0.092 in T1² stage,0.678±0.115 in T3 stage,0.675±0.101 in T4 stage;（3）0.648±0.09 in N0 stage,0.679±0.124 in N1stage,0.664±0.127 in N2 stage;（4）0.679±0.094 in tumor diameter<5cm group,0.614±0.115 in diameter≥5cm group.DCE-MRI and pathological staging and grading analysis results:1.There was significant difference in Ve and Kep between two different tumor size groups（P<0.05）.There was no significant difference in the K^transrans between the two groups（P>0.05）.2.There was significant difference in K^trans,Kep and Ve among the different pathological grade groups（P<0.05）.3.In different pathological T stages rectal cancer,significant difference of K^transrans were found in the three groups（p<0.05）.While the difference of Kep and Ve value was not significantly（p>0.05）.4.There was no significant difference in K^trans,Kep,Ve among different N stages of rectal cancer（P>0.05）.5.The rectal cancer diagnostic threshold of tumor K^transrans was0.869min^-1,which was an indicator to judgeⅠ-Ⅱstages andⅢ-Ⅳstages（≤0.869min^-11 forⅠ-Ⅱstages,>0.869min^-11 forⅢ-Ⅳstages）.The diagnostic sensitivity and specificity was59.0%and 99%.6.The rectal cancer diagnostic threshold of tumor Ve was 0.631,which was an indicatortojudgewelldifferentiatedandmoderatelyorpoorly differentiated（≤0.631 for well differentiated,>0.631 formoderately or poorly differentiated）.The diagnostc sensitivity and specificity was 71.0%and 90%.7.The pathological T stage of rectal cancer had positive correlation with K^transrans of tumor（r=0.403,P<0.01）.（2）The pathological grade of rectal cancer had positive correlation with the K^transrans of tumor（r=0.275,P<0.05）.（3）The tumor size of rectal cancer was negatively correlated with theVeof tumor（r=-0.274,P<0.05）.conclusion:DCE-MRI quantitative parameters and rectal cancer classification and staging there is a certain correlation.The T stage of rectal cancer was positively correlated with the K^transrans value of the tumor.The pathological grade and the K^transrans value of rectal cancer were also positively correlated.Those informations can provide a meaningful reference value for preoperative diagnosis and clinical prognosis of rectal cancer.