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Diagnostic value of intravoxel incoherent motion diffusion weighted imaging?IVIM-DWI?in differentiating poorly differentiated adenocarcinoma from moderately differentiated adenocarcinoma in rectal cancerBackgroundThe conventional diffusion-weighted imaging?DWI?simply reflects the diffusion movement of water molecules,but it ignores the perfusion of microcirculation of capillary blood flow.IVIM-DWI can separate the diffusion of water molecules and the perfusion of microcirculation blood flow of tumor tissue,which can accurately display the information of the density of water molecules and the microcirculation perfusion in tumor cells.Besides,it can indirectly reflect the differentiation degree and histological type of malignant tumor.ObjectiveTo investigate the diagnostic value of intravoxel incoherent motion diffusion weighted imaging?IVIM-DWI?in differentiating poorly differentiated adenocarcinoma from moderately differentiated adenocarcinoma in rectal cancer.Methods47 patients with rectal cancer confirmed by pathology were retrospectively analyzed.All the patients are divided into two groups,the poorly differentiated and the moderately differentiated.These patients with rectal carcinoma underwent routine MR scan?include axial T1WI,axial T2WI,sagittal T2WI,coronal T2WI,dynamic contrast-enhanced axial LAVA-FLEX and sagittal LAVA-FLEX?and IVIM-DWI?Single shot echo planer imaging are used.b=0?10?20?50?100?200?400?800?1200?2000 s/mm2?.SPSS 19.0 software was applied to compare the ADC,D,D*and f value in two groups.The statistical test is two independent sample t-test.Besides,the AUC is adopted to evaluate the diagnostic efficiency.ResultsThe ADC,D,D*and f value in moderately differentiated rectal carcinoma were?0.84±0.12?×10-3mm2/s,?0.62±0.12?×10-3mm2/s,?11.92±9.86?×10-3mm2/s,0.37±0.09.The group of the poorly differentiated were?0.78±0.11?×10-3mm2/s,?0.42±0.11?×10-3mm2/s,?3.83±1.31?×10-33 mm2/s,0.49±0.13.There was no significant difference between the two groups?t=1.23,P>0.05?in terms of ADC value.However there was significant difference between the two groups?the value of t are respectively 4.535,4.874,3.436,P<0.05?in terms of D,D*and f value.Besides the AUC of D,D*and f is 0.923,0.898 and 0.803.ConclusionThe D,D*and f value of IVIM-DWI have a certain value to identify the poorly or moderately differentiated preoperative rectal carcinoma.Besides the AUC of D is at its maximum,which has the better diagnostic efficiency in differentiating poorly differentiated adenocarcinoma from moderately differentiated adenocarcinoma in rectal cancer.Part ? The application of cMRI combined with texture analysis based on T2 WI in distinguishing rectal mucinous adenocarcinoma from non mucinous adenocarcinomaBackgroundTexture analysis,as a new field of radiomic,mainly describes the gray intensity relationship between pixels or voxels in the image through computer software,so as to find the details that are difficult to observe in the image,and then objectively and quantitatively evaluate the heterogeneity of the tumor.Therefore,it has the potential to reflect the differentiation degree and histological type of malignant tumors.ObjectiveTo explore the value of texture analysis based on T2 WI sequence of MRI in distinguishing rectal mucinous adenocarcinoma from partial mucinous adenocarcinoma and mucinous adenocarcinoma.MethodsThe clinical and imaging data of 41 patients with pathologically confirmed rectal cancer were analyzed retrospectively.They were divided into three groups,the 22 cases of rectal classic adenocarcinoma,the 11 cases of partial mucinous adenocarcinoma and the 8cases of mucinous adenocarcinoma.ITK-SNAP software was applied to draw ROI manually in three consecutive layers on the T2 WI sequence with the largest solid component of tumor as the center.The ROI file was imported into the AK software of GE company,and different texture parameters are used to extract features,so as to get the texture feature of the tumor.Skewness,kurtosis,uniformity,standard deviation and mean value are selected as parameter indexes.The SPSS software's one-way ANOVA analysis,LSD-t test and Kruskal-Wallis test were used to compare the three groups of data,then analyze whether there was statistical differenceamong the three groups of texture parameters.ResultThe mean value,entropy,uniformity,skewness,kurtosis and standard deviation in CAC group were?423.05±107.27?,?6.16±0.27?,?0.88±0.03?,?0.41±0.56?,?0.75,2.03?,?50.48±13.26?.The group of PMAC were?463.89±112.14?,?6.67±0.33?,?0.81±0.62?,?0.33±0.77?,?0.64,2.32?,?91.25±37.23?.The group of MAC were?545.16±115.82?,?7.05±0.28?,?0.73±0.51?,?0.28±0.79?,?0.05,1.29?,?150.15±48.99?.There was no significant difference?P>0.05?among the mean value,skewness and kurtosis in the differential diagnosis of classic adenocarcinoma,partial mucinous adenocarcinoma and mucinous adenocarcinoma whereas the difference was significant?P<0.05?among the entropy,uniformity and standard deviation of the three groups,respectively.ConclusioncMRI combined with the texture parameters based on T2 WI sequence can help to distinguish rectal classic adenocarcinoma,mucinous adenocarcinoma and partial mucinous adenocarcinoma,besides,texture analysis has a clinical significance in the differentiation of rectal classic adenocarcinoma and partial mucinous adenocarcinoma. |
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