The Study Of Magnetic Resonance Imaging Characteristics For The Diseases Of Orbital Masses

Objectives:To observe the characteristics of general magnetic resonance imaging for orbital space-occupying lesions and explore the application value and significance of conventional MRI in the diagnosis and differential diagnosis of orbital space-occupying lesions.To compare the differences of the quantitative parameters in DCE-MRI for different types of orbital space-occupying lesions,and to explore the diagnostic efficacy of DCE-MRI in the diagnosis of malignant orbital tumors.Methods:The clinical data and MRI imaging data of 145 patients who were admitted to our hospital from May 2012 to October 2016 were collected,and the clinical data,including age,gender,orbital involvement and pathological diagnosis,were summarized and recorded.The imaging characteristics including T1WI signal intensity and evenness,T2WI signal intensity and evenness,tumors,shape,position,boundary of MRI in patients with different pathological types were compared and analyzed.SPSS19.0 statistical analysis software was used to conduct the four-cell table chi-square test to compare the composition ratio of MRI with clear boundaries in benign and malignant space-occupying lesions.The measurements of the quantitative parameters:The DCE-MRI imaging datas of 86 patients with orbital space-occupying lesions were collected,and the images were performed using Siemens 3.0T MR syngo postprocessing station,the region of interest?ROI?was plotted,and the time-intensity curves?TIC?were generated,and the quantitative parameters Ktrans value,Kep value,Ve value and iAUC were calculated.The DCE-MRI quantitative parameters were compared in groups:To compare the quantitative parameters differences among the orbital vascular malformation,benign tumors,malignant tumors,the differences between the orbital benign space-occupying lesions and the orbital malignant space-occupying lesions,the differences between the orbital vascular malformation and the orbital tumors,the differences between the orbital nonspecific inflammatory reaction and the orbital lymphoma.To compare the TIC profiles in groups:To compare the differences of the TIC curve composition among the orbital vascular malformation,orbital benign tumors and orbital malignant tumors,and to compare the differences of the TIC curve ratio between the non-specific orbital inflammatory responses and lymphomas.To evaluate the diagnostic efficacy of DCE-MRI quantitative parameters:Receiver operating characteristic curve?ROC?was used to analyze the diagnostic efficacy of the quantitative parameters for the diagnosises of the orbital malignant lesions.The statistical software and methods:The t-test for the two independent samples was used to compare the mean values of quantitative parameters,and P<0.05 was considered to be statistically significant;The comparison of the TIC component ratio among the vascular malformations group,benign tumors group and malignant tumors group was performed by the bidirectional disordered contingency table analysis,and P<0.05 was considered to be statistically significant;Chi-square test was used to compare the differences between the non-specific orbital inflammatory response and lymphoma about TIC types,genders ratio.Results:There were 145 cases of orbital space-occupying lesions,including 68males and 77 females,with an average age of 45.0 years±20.24 years?x±s?,71cases of right orbital involvement,66 cases of left orbital involvement and 8 cases of bilateral orbital involvement;Among the 145 cases of orbital space-occupying lesions,there were 111 cases of benign space-occupying lesions which including 22cases of vascular malformation,89 cases of benign tumors and 34 cases of malignant space-occupying lesions;Most of the orbital space-occupying lesions are located in the orbital muscle cone,external muscle cone and lacrimal gland area,Other areas include subcutaneous of the eyelid,lacrimal sac region,nasoorbital border,cranioorbital border,mixed regions and other locations;Orbital benign space occupying lesions have many types of shapes,most of which are circle–like,elliptic,irregular and lumpy,while malignant tumors are mainly irregular and lumpy shapes;The MR images of orbital malignant space-occupying lesions showed that the proportion of borderline blurred was larger than that of benign space-occupying lesions,P<0.05,and the difference was statistically significant;Most orbital space-occupying lesions on T1WI presented isointensity,lipid-like space-occupying lesions and cystic lesions with more protein components were mostly presented as short T1 signal,and confounding T1 signals were mainly vascular lesions,langerhans cell hyperplasia,neurilemmoma and some malignant tumors;Most of the orbital space-occupying lesions whose T2 signals were homogeneous showed the long or slightly long T2 signal,mixed signals ratio in T2WI were significantly higher than that of T1WI,the lesions which show the mixed T2 were mainly the vascular lesions,schwannomas,plexiform neurofibromas,lacrimal gland adenoid cystic carcinomas,langerhans cell hyperplasias and other benign and malignant tumors.DCE-MRI TIC curve types:The TIC composition of vascular malformations,orbital benign tumors and orbital malignant tumors was compared,P<0.05,and the difference was statistically significant.The comparison of the DCE-MRI quantitative parameters:The comparison of DCE-MRI quantitative parameters-Ktrans value,Kep value and iAUC between benign and malignant orbital space-occupying lesions showed statistically significant difference?P<0.05?,while the Ve value showed no statistically significant difference?P>0.05?;The comparison of DCE-MRI quantitative parameters-Ktrans value and Kep value between the orbital benign and malignant tumors showed statistically significant difference?P<0.05?,while the Ve value and iAUC showed no statistically significant difference?P>0.05?;The quantitative parameters-Ktrans value,Kep value and iAUC of DCE-MRI of the orbital vascular malformation and benign tumors were compared,P<0.05,the difference was statistically significant,while the Ve value was compared,P>0.05,the difference was not statistically significant;The quantitative parameters-Ktrans value,Kep value and iAUC of the DCE-MRI of the orbital vascular malformation and malignant tumors were compared,P<0.05,the difference was statistically significant,while the Ve value was compared,P>0.05,the difference was not statistically significant;The quantitative parameters-Ktrans value,Kep value and iAUC of the DCE-MRI of the orbital vascular malformation and neoplastic lesions were compared,P<0.05,the difference was statistically significant,while the Ve value was compared,P>0.05,the difference was not statistically significant.The comparison between the orbital nonspecific inflammatory response and lymphoma:The comparison of the TIC curve composition between the orbital non-specific inflammatory response and orbital lymphoma showed that P<0.05,and the difference was statistically significant;The nonspecific orbital inflammatory response was compared with orbital lymphoma in terms of age,sex ratio and orbital invasion ratio,and the difference was not statistically significant?P>0.05?;The comparison of the quantitative parameters-Ktrans value,Kep value and iAUC between the orbital non-specific inflammatory response and lymphoma showed that P>0.05,the difference was not statistically significant,while the Ve value was statistically significant?P<0.05?.The evaluation of diagnostic efficacy of the DCE-MRI quantitative parameters:All three diagnostic methods which including Ktrans value,Kep value and iAUC are effective in the the diagnosis of malignant tumors;The area under ROC curve of Ktrans value,Kep value and iAUC was 0.759,0.764 and 0.752,respectively,with medium diagnostic value;If the threshold is set as the Ktrans value>0.234 min^-1,the sensitivity and specificity of the diagnosis for the malignant tumors are 89.8%and 62.1%;If the threshold is set as the Kep value>0.317 min^-1,the sensitivity and specificity of the the diagnosis for the malignant tumors are 96.4%and 51.7%;If the threshold is set as the iAUC>29.223,the sensitivity and specificity of the diagnosis for the malignant tumors are82.1%and 69.0%.Get rid of vascular malformation,Ktrans value,Kep value are effective in the the diagnosis of malignant tumors;The area under ROC curve of Ktrans value,Kep value were0.694 and 0.697,respectively,with general diagnostic value;If the threshold is set as the Ktrans value>0.239 min^-1,the sensitivity and specificity of the diagnosis for the malignant tumors are 92.9%and 55.6%;If the threshold is set as the Kep value>0.323 min^-1,the sensitivity and specificity of the the diagnosis for the malignant tumors are 96.4%and 47.2%.Conclusions:The manifestations of the locations,shapes and boundaries in MR images of orbital space-occupying lesions are of important clinical significance for the pathological diagnosis and the differentiation of benign and malignant lesions;The signal characteristics of MRI T1WI,T2WI and fat suppression images have important clinical significance for the analysis of orbital space-occupying properties and component characteristics;MRI has certain clinical specificity in the diagnosises and differential diagnosise of individual orbital space-occupying lesions,but the clinical evaluation and prediction of most orbital space-occupying lesions should be combined with clinical features,such as age,gender,orbital involvement,clinical symptoms,signs,etc.The composition ratio of vascular malformation,orbital benign tumor and orbital malignant tumor TIC was different.The vascular malformations,TIC curves were mainly type I,the TIC curves of orbital benign tumors were mainly type II and type III,and orbital malignant tumors,TIC curve were mainly type III;Compared with the orbital lymphoma,the TIC curves of the orbital non-specific inflammatory response were mainly type II and type III,while the orbital lymphoma TIC curves were mainly type III;There were no significant differences between orbital non-specific inflammation and orbital lymphoma in age,sex ratio,orbital invasion;The mean values of partial quantitative parameters of DCE-MRI for benign and malignant orbital space-occupying lesions were different,and the Ktrans value,Kep value and iAUC could be used as the reference for the differential diagnosis;The average values of partial quantitative parameters of DCE-MRI between benign and malignant tumors wer different,and the Ktrans value and Kep value could be used as the reference index for the differential diagnosis;The mean values of partial quantitative parameters between orbital vascular malformation were different from that of benign tumor and malignant tumor,and the Ktrans value and Kep value could be used as the reference index for the differential diagnosis;The mean value of Ve was different between the non-specific orbital inflammatory response and lymphoma,but its clinical significance remains to be discussed;It has certain diagnostic value for the malignant orbital tumors to setting the threshold of the Ktrans value,Kep value and iAUC.