Objective To select important features for the differentiation of growth hormone deficiency(GHD)and idiopathic short stature(ISS)by analyzing the clinical and imaging features in patients with short stature.Methods The clinical data and pituitary MRI images of 139 children with short stature were analyzed retrospectively.According to the growth hormone(GH)stimulation test,a peak GH level＜10 ng/mL was considered GHD group,while≥ 10 ng/mL was ISS group.Independent sample t-test,x2 test,and Mann-Whitney U test were used to compare the differences between the two groups.The indicators with statistically significant differences between the two groups were included in a binary logistic regression analysis to identify independent factors that differentiate GHD from ISS.Additionally,the receiver operating characteristic(ROC)curve was used to assess the diagnostic efficacy.Partial correlation analysis was performed to evaluate the association between adenohypophysis volume(aPV)and peak GH.Results Body mass index(BMI)was significantly higher in the GHD group than that in the ISS group,while free triiodothyronine(FT3),adenohypophysis height(aPH),and aPV were significantly lower than those in the ISS group(P＜0.05).Binary logistic regression analysis results showed that aPV[odds ratio(OR)=0.984,95％confidence interval(CI)0.974-0.994,P=0.002],BMI(OR=1.835,95％CI 1.377-2.446,P＜0.001),FT3(OR=0.249,95％CI 0.075-0.828,P=0.023)were independent factors in differentiating GHD and ISS.The area under the curve(AUC)of the combined differential diagnostic for these three indicators were 0.929(0.873-0.966),with a sensitivity of 89.47％and a specificity of 92.08％.Partial correlation analysis results showed that aPV was positively correlated with peak GH(r=0.300,P＜0.001).Conclusion The assessment of aPV by pituitary MRI,combined with clinical indicators,can be a useful method to differentiate between GHD and ISS.

Objective To select important features for the differentiation of growth hormone deficiency(GHD)and idiopathic short stature(ISS)by analyzing the clinical and imaging features in patients with short stature.Methods The clinical data and pituitary MRI images of 139 children with short stature were analyzed retrospectively.According to the growth hormone(GH)stimulation test,a peak GH level＜10 ng/mL was considered GHD group,while≥ 10 ng/mL was ISS group.Independent sample t-test,x2 test,and Mann-Whitney U test were used to compare the differences between the two groups.The indicators with statistically significant differences between the two groups were included in a binary logistic regression analysis to identify independent factors that differentiate GHD from ISS.Additionally,the receiver operating characteristic(ROC)curve was used to assess the diagnostic efficacy.Partial correlation analysis was performed to evaluate the association between adenohypophysis volume(aPV)and peak GH.Results Body mass index(BMI)was significantly higher in the GHD group than that in the ISS group,while free triiodothyronine(FT3),adenohypophysis height(aPH),and aPV were significantly lower than those in the ISS group(P＜0.05).Binary logistic regression analysis results showed that aPV[odds ratio(OR)=0.984,95％confidence interval(CI)0.974-0.994,P=0.002],BMI(OR=1.835,95％CI 1.377-2.446,P＜0.001),FT3(OR=0.249,95％CI 0.075-0.828,P=0.023)were independent factors in differentiating GHD and ISS.The area under the curve(AUC)of the combined differential diagnostic for these three indicators were 0.929(0.873-0.966),with a sensitivity of 89.47％and a specificity of 92.08％.Partial correlation analysis results showed that aPV was positively correlated with peak GH(r=0.300,P＜0.001).Conclusion The assessment of aPV by pituitary MRI,combined with clinical indicators,can be a useful method to differentiate between GHD and ISS.

Objective To evaluate the dynamic contrast-enhanced MRI (DCE-MRI)in detecting experimentally induced testicular ischemia. Methods Thirty healthy male New Zealand rabbits were randomly assigned into 6 groups. There were 5 rabbits in each of the following experimental groups: ( 1 ) Normal control, (2) Sham-operated, (3) ischemia of 3 h group, (4) ischemia of 6 h group, (5) ischemia of 12 h group, (6) ischemia of 24 h group. In all experiment groups, the right testis served as the internal control while the left testis served as the experimental side. DCE-MRI for each animal lasts about 10 minutes. Signal enhanced ratios (SERs) of ROI for both sides of each group were calculated by a computer, and parameters of SERs of 30 s, 75 s, 120 s and maximal SER were used for statistical analysis.Time intensity curves (TICs) were made for two sides of each group via Excel 2003 software and classified into 4 types. Statistical analysis was performed to compare the differences of SERs between left and right testis by two independent Kolmogorov-Smirnov test. Results In group I and 2, significant enhancement was observed on both testes of 10 rabbits. The enhancement decreased gradually with the elongation of ischemia in torsion groups. Three cases of type Ⅰ and 2 cases of type Ⅱ were observed in group 1,5 cases of type Ⅰ in group two, 2 cases of type Ⅰ and 3 cases of type Ⅱ b in group three, 2 cases of type Ⅰ and 2 cases of type Ⅱ b in group four, 5 cases of type Ⅱ b in group five and 5 cases of type Ⅲ in group six were noticed in the left testes. And in TICs of right testes, all cases showed TICs of type Ⅰ except 2 cases of type Ⅱ a in group six. In four torsion groups, the values for SER75 of the left side were 0. 084%, 0. 076%, 0.164% and 0.065%, while the right side were 0.255%, 0.410%, 0.586% and 0.302% (P ＜0.05). The values for SER120 in group three, five and six were 0.221% , 0.158% and 0.059% for the left side, and 0.405%,0.522% and 0.207% for the right side(P ＜0.05). The values for MSER in group three, five and six were 0.217% ,0.164% and 0.072% for the left side, and 0.405%, 0.586% and 0.302% for the right side(P ＜0.05). Conclusion DCE-MRI technique may be useful in the diagnosis of testicular torsion, which shows potential in the clinical application.