The Application Research Of Multimodal MRI In The Differential Diagnosis Of Orbital Lymphoproliferative Diseases

Purpose:To evaluate the role of diffusion weighted imaging(DWI)and the derived apparent diffusion coefficient(ADC)in differentiating malignant from benign orbital lymphoproliferative disorders(OLPDs).Materials and methods:Thirty-three patients(benign:malignant=15:18)with OLPDs were enrolled in our study.Whole-tumor regions of interest(ROIs)were drawn on all slices of the ADC maps to acquire mean ADC value(ADC_M).Independent sample t test was used to compare the ADC_M between two groups.Receiver operating characteristic(ROC)curve analysis was used to determine the diagnostic value of ADC_M in differentiating malignant from benign OLPDs.Results:The ADC_M value of benign OLPDs group was 0.94±0.24×10~-33 mm~2/s,while that of the malignant OLPDs group was 0.69±0.15×10~-33 mm~2/s.Benign group showed significantly higher ADC_M value than malignant group.Setting the ADC_M value of 0.886×10~-33 mm~2/s as the cut-off value,the optimal diagnostic value could be achieved(AUC,0.796;sensitivity,0.944;specificity,0.667)in differentiating malignant from benign OLPDs.Conclusion:DWI and the derived ADC value might be helpful in differentiating malignant from benign OLPDs.Purpose: To assess the value of dynamic contrast enhanced magnetic resonance imaging(DCE-MRI)in differentiating malignant from benign orbital lymphoproliferative disorders(OLPDs).Materials and Methods: Thirty-nine patients with orbital lymphoproliferative disorders(21 malignant and 18 benign)underwent DCE-MRI scan for pre-treatment evaluation between March 2013 and December 2015.Both semi-quantitative(TTP,AUC,Slopemax)and quantitative(Ktrans,Kep,Ve)parameters were calculated,and compared between two groups using unpaired t test.Receiver operating characteristic(ROC)curve analyses were used to determine the diagnostic value of each significant parameter.Results: Malignant OLPDs showed significantly higher Kep,lower Ve,and lower AUC than benign OLPDs,while no significant differences were found on Ktrans,TTP and Slopemax.ROC analyses indicated that Ve exhibited the best diagnostic performance in predicting malignant OLPDs(cut-off value,0.211;area under the curve,0.896;sensitivity,76.2%;specificity,94.9%),followed by Kep(cutoff value,0.853;area under the curve,0.839;sensitivity,85.7%;specificity,89.9%).Conclusion: DCE-MRI and specially its derived quantitative parameters of Kep and Ve are promising metrics for differentiating malignant from benign OLPDs.Purpose: To determine the optimal combination of parameters derived from 3.0T multi-parametric [conventional magnetic resonance(MR),diffusion weighted(DW)and dynamic contrast-enhanced(DCE)] MR imaging for differentiating malignant from benign orbital lymphoproliferative disorders(OLPDs).Materials and Methods: Forty patients with OLPDs(18 benign and 22 malignant)underwent conventional 3.0T MR,DW and DCE-MR imaging examination for pre-surgery evaluation.Conventional MR imaging features(including tumor laterality,shape,number of involved quadrants,signal intensity on T1 WI and T2 WI,flow void sign on T2 WI,and findings suggestive of sinusitis)were reviewed,and multivariate logistic regression analysis was used to identify the most significant conventional MR imaging features.Apparent diffusion coefficient(ADC)and DCE-MR imaging derived parameters(area under curve,AUC;time to peak,TTP;maximum rise slope,Slopemax)were measured and compared between two groups.Receiver operating characteristic(ROC)curve analyses were used to determine the diagnostic ability of each combination that was established based on identified qualitative and quantitative parameters.Results: Multivariate logistic regression analysis showed that presence of flow void sign on T2 WI significantly associated with benign OLPDs(P=0.034).Malignant OLPDs demonstrated significantly lower ADC(P=0.001)and AUC(P=0.002)than benign mimics.ROC analyses indicated that,ADC alone showed the optimal sensitivity(threshold value,0.886×10-3 mm2/s;sensitivity,90.9%),while combination of no presence of flow void sign on T2 WI + ADC?0.886×10-3 mm2/s + AUC?7.366 showed optimal specificity(88.9%)in differentiating benign from malignant OLPDs.Conclusions: Multi-parametric MR imaging can help to differentiate malignant from benign OLPDs.DW imaging offers optimal sensitivity,while the combination of conventional MR,DW and DCE-MR imaging offers optimal specificity.