Diagnostic Value Of Routine MRI Scan And Multiple B Value DWI Scan In Orbital Lymphoproliferative Lesion

Objective:To explore the diagnostic ability and differential diagnosis of Orbital lymphoproliferative lesion by routine MRI scan and multiple b value DWI scan,and to provide more information for clinical diagnosis and treatment.Materials and Methods:In this study,67 patients with orbital lymphoid tissue hyperplasia diagnosed pathologically after operation were collected.All patients were diagnosed and treated for the first time or did not receive related treatment.All patients underwent routine binocular mri scan before operation,and 39 patients underwent binocular routine mri scan combined with multiple b value DWI scan.Average age of patients is 59(±13),male:female?1.3:1.All the patients were divided into two groups:a(benign group),b(malignant group)and two imaging physicians with more than 5 years experience were selected to read the films in double-blind diagnosis of ocular images.By observing and analyzing the location of lesion(unilateral and bilateral),the range of involvement(anterior orbital septum space,lacrimal gland area,intraconical space/outer space of muscle cone),boundary(clear,unclear),intensity of signal and enhancement,whether to wrap around the eyeball and other structures(yes,no),whether the extraocular muscle is involved(yes,no)and whether the orbital bone is involved,etc.qualitative factors.And through the SPSS.25.0 statistical software,analysing the above qualitative results are whether statistically significant.In addition,ADC values at different b values were measured on workstations for patients who underwent MRI routine scanning combined with multiple b value DWI.The quantitative results were analyzed by SPSS.25.0 software,whether there were differences between ADC values under different b values,ADC values among benign masses and ADC values among malignant masses under different b values,whether there is difference in ADC between benign and malignant masses with the same b value were analyzed.According to the ADC value of different b values,the sensitivity of benign and malignant Orbital lymphoproliferative lesion(SE),specific(SP),positive predictive value(PPV),negative predictive value(NPV)are judged to draw ROC curve.The best b value for benign and malignant orbital masses was obtained by area under the curve(AUC).Results:There were significant differences between the two groups in the lacrimal gland area,the intrapyramidal space and the outer space area(P<0.05),but there was no significant difference in the anterior orbital septum space between the two groups(P>0.05).There was no statistical difference between the two groups(p>0.05)in terms of lesion boundary,surrounding structure,extraocular muscle involvement,bone involvement and signal intensity(P>0.05).The difference of ADC value between different b values was statistically significant(p<0.05),and the value of ADC from small to large was b=400<b=800<b=1000s/mm~2.Under different b values,there were differences between ADC of benign and malignant masses.At the same b value,the difference of ADC between benign and malignant masses was statistically significant(P<0.05).,AUC(area under the curve)was the largest in b=1000s/mm~2.Conclusion:The ability of routine MRI scan to diagnose Orbital lymphoproliferative lesion is limited,but some imaging features have statistical significance in differentiating benign and malignant diseases.Multiple b value DWI scan has significance in differentiating benign and malignant orbital masses.When b=1000s/mm~2,the differential ability is the best.