Association Between Extramural Vascular Invasion And Quantitative Parameters Of Functional Magnetic Resonance Of Microcirculation In Rectal Cancer

Part ? Quantitative Evaluation of the Relationship between Microstructure of Rectal Cancer and Extramural Vascular Invasion Objective:This study explored whether the I VIM parameters of patients with different mrEMVI states were different to determin the potential relationship between mrEMVI states and tumor microstructionMaterials and methods:Retrospective analysis of MRI images(scanning sequence including IVIM sequence)of 49 patients with rectal cancer pathologically confirmed from April 2019 to January 2020 was performed to diagnose whether the lesion has extramural vascular invasion by three radiologists.The patients were divided into mrEMVI positive group and mrEMVI negative group.The bi-exponential model of software Shortcut to DWI was used to fit the original IVIM multib-valued DWI image.The model was then imported into Image J analysis software to measure the IVIM parameter values(D,D*,and f-values)of rectal adenocarcinoma patients.The necrosis,edema and vascular areas were not selected in ROI selection.The measurement was repeated by three times and the average was calculated.The IVIM parameters and clinical data of the two groups of patients were analyzed and compared.In addition,the effect curves were used to evaluate its diagnostic efficacy of mrEMVI.Results:There were no significant differences in the f and D*values in the I VIM sequence between the mrEMVI positive group and the mrEMVI negative group.The D value of mrEMVI positive group was significantly lower than that of mrEMVI negative group.The AUCs of D,D*and f-values for diagnosing extravascular wall invasion of rectal cancer were 0.659,0.615 and 0.494,respectively.The P value of D value is less than 0.05,and the diagnosis of the D value is low.Both the P-values of D*and f-value were greater than 0.05,indicating that the diagnostic efficacy results were caused by random errors.The diagnostic sensitivities of D,D*,and f values were 0.346,0.308,and 0.769,and the specificities were 0.957,1.000,and 0.391.Conclusion:(1)The D value of mrEMVI-positive patients in this study was significantly smaller than that of mrEMVI-negative patients,and the difference was statistically significant,which suggests that rectal cancer with active tumor cell proliferation and higher tumor cell density is more likely to invade outside the wall.(2)The f value of mrEMVI-positive was slightly higher than that of the mrEMVI-negative group,but the D*value was slightly lower than that of the mrEMVI-negative group.There was no significant difference in the D*value and f value parameters between the two groups.These results reveal that the parameter values of microcirculation perfusion represented by the IVIM sequence are not effective in predicting EMVI,and further research is needed in the future(3)In terms of diagnostic efficacy,D values have low diagnostic efficacy for extravasation of rectal cancer vessels,which need to be further explored in the future.Part ? The quantitatively evaluation of DCE-MRI on the elationship between rectal cancer microcirculation and extramural vascular invasionObjective:In this study,we investigated whether the DCE-MRI parameters of patients with different mrEMVI states were different to determine the potential relationship between mrEMVI states and tumor microcirculation.Materials and methods:Retrospective analysis of MRI images(scan sequence including DCE-MRI sequence)of 49 patients with rectal cancer pathologically confirmed from April 2019 to January 2020.Three radiologists diagnosed whether the lesion had an extramural vascular invasion.Then,the patients were divided into mrEMVI positive group and mrEMVI negative group.All DCE-MRI images were transferred to the philips post-processing workstation,and the image data was analyzed and processed using MR Permeability post-processing software that uses a two-compartment pharmacokinetic Tofts model to quantitatively analyze the DCE-MRI data.The necrosis,edema and vascular areas need to be avoided during ROI selection,and the measurement was repeated three times and the average value was taken as the final measurement value.The DCE-MRI parameters and clinical data of the two groups of patients were compared,and the effect curves were used to evaluate their efficacy in predicting mrEMVI.Results:Ve value was not significantly different between mrEMVI positive group and mrEMVI negative group,however,Ve value was higher in mrEMVI positive group than in negative group.The Ktrans value and Kep value of mrEMVI positive group were significantly higher than those of mrEMVI negative group,and the difference was statistically significant.Values of Ktrans,Kep,and Ve were 0.883,0.694,and 0.667 for the diagnosis of extravasational vascular invasion of rectal cancer,and the P values were all less than 0.05.The diagnostic effect of Ktrans value is relatively high,while the diagnostic value of Kep and Ve value is relatively low.The diagnostic sensitivity of Ktrans,Kep and Ve values were 0.667,1 and 0.933,respectively;with the specificity at 0.966,0.483 and 0.517,respectively.Conclusion:(1)The Ktrans and Kep values of the mrEMVI positive group were significantly higher than those of the mrEMVI negative group,and the differences were statistically significant,suggesting that Ktrans and Kep are related to tumor vascular invasion.Ktrans and Kep mainly reflect the vascular surface permeability and blood flow velocity of the tissue,which suggests that the capillaries in the rectal cancer tissue of the mrEMVI positive group have higher permeability and blood flow velocity.(2)In terms of diagnostic efficacy,the Ktrans value,whose diagnostic specificity is high and false positive rate is low,is recommended.