ADC Values Variation With Age In Normal Testes And Differential Diagnosis Of Testicular Lesions At 3.0T DWI

Part? ADC values variation with age in normal testes at 3.0 T diffusion weighted imagingObjectives: To explore the apparent diffusion coefficient(ADC) values variation with age in normal testes at 3.0 T diffusion weighted imaging(DWI).Materials and Methods: We collected sixty healthy volunteers, divided into four groups by age: group A(10-19 years, n=10); group B(20-39 years, n=27); group C(40-64 years, n=16); group D(65-85 years, n=7). DWI was performed using 8 b values(50, 100, 500, 1000, 1500, 2000, 2500, and 3000 s/mm2). The signal intensity(SI) of bilateral testicular parenchyma, vastus medialis were measured and the testis-to-muscle SI contrast were calculated for all b values. ADC values were calculated using different b-value combinations(50, 500; 50, 1000; 50, 1500; 50, 2000; 50, 2500; 50, 3500 s/mm2). The differences of SI with bilateral testicular parenchyma were compared using paired t-test; the differences of SI contrast and ADC values between the age groups were compared using ANOVA analysis,the correlations of SI contrast and ADC values with age were evaluated using Pearson correlation analysis.Results: The SI of right testicular parenchyma was lower than the left, but there was no statistically significant difference(all p> 0.05) under all b values. The differences of SI contrast among the age groups had statistical significance for b values at 100,500,1000,1500,2000,2500,3000s/mm2, SI contrast were negatively correlated with age, and the correlation coefficient r was 0.551, 0.451, 0.507, 0.445, 0.474, 0.498 and 0.531, respectively(all p < 0.05). The differences of ADC values among the age groups had statistical significance for all b-value combinations( 50, 500; 50, 1000; 50, 1500; 50, 2000; 50, 2500; 50, 3500 s/mm2)(all p< 0.05), ADC values were positively correlated with age, and the correlation coefficient r was 0.483, 0.411, 0.416, 0.387, 0.390 and 0.368, respectively(all p < 0.05).Conclusion: With increasing age, the SI contrast of testicular parenchyma reduces, and ADC values increases.Part? Differential diagnosis of testicular lesions at 3.0 T diffusion weighted imagingObjectives: To explore the optimal b-value of 3.0T diffusion weighted imaging(DWI) for the differential diagnosis of testicular lesionsMaterials and Methods: Thirty-eight patients with clinically and histologically confirmed diagnosis of testicular lesions were recruited in this study(including 26 cases of malignant lesions and 12 cases of benign lesions). All patients underwent DWI using eight b values(50, 100, 500, 1000, 1500, 2000, 2500, 3000 s/mm2). The signal intensity(SI) of lesions, contralateral testicular parenchyma, and vastus medialis were measured and the lesions(testis)-to-muscle SI contrast were calculated for all b values. ADC values were calculated using b value combinations as follows:50, 500; 50, 1000; 50, 1500; 50, 2000; 50, 2500; 50, 3500 s/mm2. we take age group B(20-39 years) as reference.the SI contrast and ADC values between contralateral normal testicular parenchyma and healthy volunteers testicular parenchyma, benign and malignant testicular lesions, seminomas and non-seminomatous germ cell tumor were compared by using two independent samples t-test. Receiver operating characteristic(ROC) analysis was performed in SI contrast and ADC values for the differential diagnosis of benign and malignant testicular lesions, seminomas and non-seminomatous germ cell tumor.Results: The differences of SI contrast and ADC values between contralateral testicular parenchyma and healthy volunteers had no statistical significance, and the differences of SI contrast between benign and malignant lesions had no statistical significance, in all b values(all p> 0.05). The ADC values of malignant lesions were lower than benign lesions in ultra-high b values(2000, 2500, 3000 s/mm2)(all p < 0.05). The SI contrast of seminomas were higher than non-seminomatous germ cell tumor in ultra-high b values(2000, 2500, 3000 s/mm2)(all p < 0.05). The ADC values of seminomas were lower than non-seminomatous germ cell tumor, there were statistically significant difference in all b values(all p< 0.05). Areas under the ROC curve for the differential diagnosis of benign and malignant testicular lesions were 0.727, 0.747, 0.758 in ultra-high b values(2000, 2500, 3000 s/mm2), with 72.2% sensitivity and 81.8% specificity for d1 fferential of benign and malignant lesions,Conclusion: The ADC values from the b value combinations 50, 500; 50, 1000; 50, 1500 s/mm2 were not sufficient to discriminate testicular lesions. The optimal b value for 3.0T DWI for testicular lesions detection was ultra-high b value(2000, 2500, 3000 s/mm2).