DCE-MRI Histogram Analysis Of The Invasiveness Of Pituitary Adenomas And The Correlation With Immunohistochemistry

Purpose:The vascular heterogeneity of invasive pituitary adenoma was quantitatively analyzed using DCE-MRI histogram(Ktrans,Ve,Kep)based on entire region of tumor.,Its correlation with Ki-67 and p53 was investigated.Diagnostic value of DCE-MRI histogram analysis in invasive pituitary adenoma was evaluated.Methods:Thirty-seven patients with pituitary tumor confirmed pathologically were enrolled in this study,which were divided into invasive group(n=18)and non-invasive group(n= 9)according to the Knosp classification standard.Imaging was performed on a 3.0 Tesla GE scanner using an 8-channel head coil,including conventional sequence and Dynamic Contrast Enhanced MRI(DCE-MRI).DCE-MRI images were scanned with LAVA-Flex sequence of 30 phases.The DCE-MRI data were digitally transferred from workstation to a personal computer and processed with Omni-Kinetics software.Referring to the coronal T1WI image,ROIs that contained the entire tumor were drawn avoiding internal carotid artery in each slice.The 3D ROI was merged slice by slice,and then the histograms voxel wise measurements of the entire tumor volume were obtained.Histogram related parameters were recorded including min intensity,max intensity,mean value,the 5th,10th,25th,50th,75th,90th and 95th percentiles,range,std deviation,variance,mean deviation,relative deviation,skewness,kurtosis,uniformity,energy and entropy.All data was analyzed with SPSS 18.0.The analysis of data used two independent samples t-test and ANOVA,Kruskal-Wallis test and Mann-Whitney U test,to analyze the difference of the maximum diameter,Knosp grade,Ki-67,p53,Ktrans,Ve and Kep histogram parameters of the invasive and non-invasive groups.Spearman correlation analysis was used to analyze the correlation between Knosp grade and Ki-67,p53,the correlation between Ktrans,Ve and Kep histogram parameters and tumor Knosp grade,and Ki-67,p53.Receiver operating characteristic(ROC)curve was used to assess the differential diagnostic ability of maximum diameter,Knosp grade,Ki-67,p53,Ktrans,Ve and Kep histogram parameters in invasive and non-invasive groups.Logistic regression analysis was used to obtain the joint variables,P<0.05 was deemed as statistically significant.Results:1.Max intensity,mean value,the 50th,75th,90th and 95th percentiles,range,mean deviation,skewness,uniformity,energy and entropy of Ktrans histogram were significant different between invasive and non-invasive pituitary adenomas group(P=0.016,0.002,0.025,0.010,0.006,0.003,0.012,0.008,0.025,0.012,0.028,0.024);the AUC of mean value,the 95th and 90th percentiles were 0.792,0.784 and 0.766 respectively,which are better for distinguishing two groups.2.Max intensity,mean value,the 95th percentiles,range,std deviation,variance,relative deviation,skewness,kurtosis,uniformity,energy and entropy of Ve histogram were significant different between invasive and non-invasive pituitary adenomas group(P=0.006,0.036,0.023,0.013,0.029,0.027,0.005,0.042,0.013,0.022,0.033,0.046);the AUC of relative deviation,max intensity and range were 0.772.0.766?0.741 respectively;3.The 90th and 95th percentiles,range,relative deviation and sk-ewness of Kep histogram were significant different between invasive and non-invasive pituitary adenomas group(P=0.031,0.013,0.042,0.005,0.023);the AUC ofrelative deviation,skewness and the 95th percentiles were 0.769?0.740?0.737 respectively;4.The AUC of joint variable 1 which was combined by the mean value of Ktrans histogram,relative deviation of Ve histogram and relative deviation of Kep histogram and joint variable 2 which was combined by the joint variable 1 and maximum diameter were 0.877?0.942 respectively;5.There was a correlation between Knosp grade and Ki-67,p53 in pituitary adenomas(r=0.547,P<0.001;r=0.617,P<0.001);6.Among all parameters,the correlation between mean value of Ktrans histogram and Knosp grading was the largest(r=0.660,p<0.001),the correlation between kurtosis of Kep histogram and Ki-67 was the largest(r=0.746,p<0.001),the correlation between mean deviation of Ktrans histogram and p53 was the largest(r=0.388,p=0.018)?Conclusion:1.DCE-MRI parameter histogram reflects the vascular heterogeneity of invasive pituitary adenoma,and be helpful for the differential diagnosis of invasive and non-invasive pituitary adenomas;2.Combination of DCE-MRI parameter histogram and maximum diameter improve the diagnosis ability of invasive pituitary adenomas;3.The kurtosis of Kep histogram and mean deviation of Ktrans histogram of pituitary adenoma has correlation with Ki-67 and p53,which can be used as an imaging biomaker to monitor the evolution of the disease.