动态增强MRI评价缺血睾丸活力演变的实验研究

目的 探讨MR动态增强扫描(DCE-MRI)在评价缺血睾丸活力演变中的价值.方法 选取30只健康雄性新西兰大白兔,采用随机数字表法分为6组,每组5只.①组为正常对照组,②组为假手术组,③、④、⑤、⑥组分别制作左侧睾丸缺血3 h、6 h、12 h和24 h模型,分别行DCE-MRI并观察睾丸信号变化.分析双侧睾丸时间-信号强度曲线(TIC)分型,并测量30 s信号强化率(SER30)、75 s信号强化率(SER75)、120 s信号强化率(SER120)和最大信号强化率(MSER).组内左右睾丸SER的比较采用两个样本分布比较的Kolmogorov-Smirnov检验.结果 ①组与②组左右侧睾丸动态增强早期明显强化,③、④、⑤、⑥组随缺血时间延长,动态强化逐渐减低;左侧睾丸TIC①组3个为Ⅰ型,2个为Ⅱa型;②组5个均为Ⅰ型;③组2个Ⅰ型,3个为Ⅱb型;④组2个为Ⅰ型,3个为Ⅱb型;⑤组5个均为Ⅱb型;⑥组5个均为Ⅲ型.右侧睾丸除⑥组2个为Ⅱa型,其余各组均为Ⅰ型.③、④、⑤、⑥组左侧SER75的中位数分别为0.084%、0.076%、0.164%和0.065%,右侧分别为0.255%、0.410%、0.586%和0.302%,差异均有统计学意义(P值均＜0.05).③、⑤、⑥组左侧SER120分别为0.221%、0.158%和0.059%,右侧分别为0.405%、0.522%和0.207%,差异均有统计学意义(P值均＜0.05).③、⑤、⑥组左侧MSER分别为0.217%、0.164%和0.072%,右侧分别为0.405%、0.586%和0.302%,差异均有统计学意义(P值均＜0.05).结论 动态增强MRI能够对睾丸不全扭转做出正确判断,对于临床诊断早期不全性睾丸扭转具有潜在应用价值.

Dynamic contrast-enhanced MRI for the detection of testicular ischemia in experimental induced testicular torsion of rabbits

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.