RESUMO
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.