The Value Of IVIM And Quantitative DCE-MRI In Differentiating Epithelial Ovarian Tumors And Their Correlation With Ki67

BackgroundOvarian neoplasms are very common in gynecological neoplasms,among which epithelial neoplasms occur most frequently.Due to the deep anatomical location of the ovary,most of the patients were in advanced stage at the time of treatment,and there were significant differences in treatment and prognosis between benign and malignant epithelial ovarian tumors.The soft tissue contrast and spatial resolution of magnetic resonance imaging（MRI）are better than other imaging examinations,which can clearly show the normal tissue anatomical structure,tumor tissue composition,surrounding tissue infiltration,and distant metastasis,thus providing certain help for clinicians to make diagnosis and treatment plans in terms of imaging.However,conventional MRI is difficult to determine the nature of some complex ovarian tumors,so it has certain limitations and misdiagnosis rate.Intravoxelincoherentmotion（IVIM）can not only reflect the diffusion of water molecules in vivo,but also reflect the capillary microcirculation perfusion information.The semi-quantitative and quantitative parameters of dynamic contrast-enhanced MRI（DCE-MRI）can reflect a variety of microcirculation changes of tumor.Immune factor Ki67 has been widely used to predict the prognosis of a variety of tumors.The purpose of this study was to explore the value of two magnetic resonance imaging techniques in differentiating benign and malignant ovarian tumors of epithelial and their correlation with ki67 expression.Part Ⅰ The Diagnostic Value of IVIM in Epithelial Ovarian Tumors and The Correlation between Its Parameters and Ki67Objective:To investigate the value of intravoxel incoherent motion（IVIM）parameters in the identification of epidermal ovarian tumors,and the correlation between ovarian cancer and ki67 expression.Methods:The data of MR plain scan,IVIM and routine enhancement examination of 73 patients with epidermal ovarian tumor（27 cases of benign tumor and 46 cases of malignant tumor）confirmed by surgical pathology were retrospectively analyzed.IVIM parameter values（ADC,Dslow,Dfast and f）were analyzed and measured,and the differences in each parameter between benign and malignant groups were compared.The ROC curve was drawn to evaluate the efficacy of various parameters in the differential diagnosis of epidermal ovarian tumors,and the diagnostic boundary value,sensitivity and specificity of each parameter were calculated;The correlation between IVIM parameter value and expression level of ki67 was analyzed.Results:ADC,Dslow and f of the benign group were all higher than those of the malignant group（all P<0.05）.There was no statistical difference in Dfast between the two groups.（P=0.059）.Among them,ADC value has extremely high sensitivity and Dslow and f value have high specificity.Dslow value had the highest efficacy in differentiating benign and malignant ovarian tumors from epidermal tumors,with the area under the ROC curve being 0.934（P<0.01）,the optimal threshold being 0.853×10^-3mm²/s,and the sensitivity and specificity being 85.2%and 87%,respectively;ADC,Dslow,and f were all negatively correlated with ki67（p<0.05）,while Dfast was not significantly correlated with ki67（p>0.05）.Conclusion:IVIM is helpful in identifying benign and malignant epidermal ovarian tumors,in which the sensitivity of ADC value is extremely high,while the specificity of Dslow and f value is high,which has certain reference significance for clinical diagnosis;Some IVIM parameters are related to the expression of ki67,so it can indirectly provide help for the prognosis assessment of ovarian cancer.Part Ⅱ The Diagnostic Value of Quantitative DCE-MRI in Epithelial Ovarian Tumors and The Correlation between Its Parameters and Ki67Objective:To investigate the value of quantitative parameters of dynamic contrast-enhanced MRI（DCE-MRI）in the identification of benign and malignant epithelial ovarian tumors,and the correlation between quantitative parameters of DCE-MRI and ki67 expression in the malignant group.Methods:MR plain scan and DCE-MRI data of 45 patients with epithelial ovarian tumors（12benign tumors and 33 malignant tumors）were prospectively collected.Parameters of DCE-MRI(K^trans,K_ep,and V_e)were measured and the differences between benign and malignant groups were compared.The ROC curve was drawn to evaluate the efficacy of each parameter in identifying benign and malignant ovarian tumors of epithelial origin,and the diagnostic cutoffs,sensitivity and specificity of each parameter were calculated.The correlation between DCE-MRI quantitative parameters and ki67 expression was analyzed.Results:K^trans and K_ep values in the malignant group were higher than those in the benign group（all P < 0.05）,and there was no significant difference in V_e values between the two groups（P=0.052）.The sensitivity of K^trans and K_ep values were high and the specificitywere moderate.K_ep value was the most effective in differentiating benign from malignant ovarian tumors（AUC=0.861）.K^trans and K_ep values were positively correlated with ki67expression（p < 0.01）,while V_e was not significantly correlated with ki67（p=0.071）.Conclusion:DCE-MRI is helpful to distinguish benign and malignant ovarian tumors of upper skin origin,and the sensitivity of K^trans and K_ep values is very high,which has certain reference value for clinical diagnosis.Some quantitative parameters of DCE-MRI were correlated with the expression of ki67,so they could indirectly contribute to the prognosis assessment of ovarian cancer.