MRI对先天性肛门直肠畸形的诊断价值

The diagnostic value of MRI on anorectal malformation

目的探讨MRI在先天性肛门直肠畸形中的诊断价值。方法搜集2002年5月至2004年5月经手术治疗的先天性肛门直肠畸形患者24例,术前均行MR检查。结果24例患者中5例肛门高位闭锁,直肠盲端均在耻骨尾骨线(PC线)以上,其到肛门窝的距离>25mm,其中2例骶尾椎发育畸形、1例合并肾脏发育畸形,2例尿道直肠瘘,1例膀胱直肠瘘;5例肛门括约肌均不对称。7例肛门中位闭锁,直肠盲端与PC线基本平齐,其到肛门窝的距离平均15mm,其中5例合并尿道瘘,2例合并前庭瘘。12例低位闭锁,直肠盲端均在PC线以下,其到肛门窝的距离<10mm。其中3例会阴部瘘。19例中低位肛门闭锁患者在T1WI加抑脂序列显示10例肛门括约肌发育良好,9例发育稍不对称。结论MRI在先天性肛门直肠畸形术前诊断准确率高,并可清晰显示瘘管及肛门括约肌,为手术方式的选择、术后并发症的预测及预后评估提供可靠的依据。

Objective To discuss the value of MRI on anorectal malformation. Methods Twentyfour cases with operatively proved anorectal malformation were collected. MR Imaging was performed in all patients. Results High location imperforate anus were demonstrated in 5 cases, the rectal end of them was above PC line, and the distance between the rectal end and anal skin pouch was more than 25 mm. Two cases of the malformation with vertebrae sacrales and caudal vertebrae and 1 case together with the malformation of kidney, 3 cases of the rectourethral fistula and rectobladdery fistula were found. The sphincter of anus were asymmetry in all the 5 cases. Seven cases were proved of middle location of imperforate anus. The rectal end was equal with PC line, the distance between the rectal end and anal skin pouch was about 15 mm. Five cases were found the fistula between the urethra and the rectum, 2 cases were found the fistula between the vestibule and the rectum. Twelve cases were proved of low location of imperforate anus. The rectal end was under PC line, the distance between the rectal end and anal skin pouch was less than 10 nun. Three cases of perineal fistula were found. The sphincter of anus was normal in 10 cases on imaging of saturated fat sequence, 9 cases were found slightly asymmetry in middle and low location imperforate anus. Conclusion In the pre-operation of imperforate anu, the located diagnosis of MRI had high accuracy, and the combinations of malformations were display clearly. It could afford the witnesses for the choice of operative fashion and the forecast of the prognosis or complication.