先天性直肠肛门畸形盆腔MR三维重建图像及临床意义

目的 建立先天性直肠肛门畸形(anorectal malformations,ARM)盆腔MR三维重建图像,探讨其临床意义.方法 患儿28例,其中先天性直肠肛门畸形组14例,男9例,女5例;年龄3 d1例,2～5个月12例,13岁1例.对照组14例,男8例,女6例;年龄3个月～10岁,平均2.9岁,为无直肠肛管疾患而因其他疾病需行盆腔或臀部MR扫描的患儿.应用Siemens 1.5T MR成像仪,对28例小儿盆腔行横断位、矢状位和冠状位T_1WI和T_2 WI扫描,横断面和矢状面T_1WI加脂肪抑制序列.采用体绘制和3D-Doctor软件进行三维重建;利用三维图像,判断直肠肓端、横纹肌复合体(SMC)位置及发育情况.结果成功建立了28例小儿盆腔的MR三维重建图像,能清晰显示直肠盲端与SMC的关系、瘘管位置.根据三维重建图像上直肠盲端和SMC的关系,14例术前接受检查的ARM患儿中,5例直肠盲端位于SMC以上,诊断为高位闭锁,4例直肠盲端部分穿过SMC,诊断为中位闭锁,5例直肠肓端完全穿过SMC,诊断为低位闭锁,与X线或造影诊断相符,并经手术证实,诊断正确率为100%.每例ARM患儿SMC大小、分布不一致,即使在同一类型的患儿也不同,高位畸形最明显.对照组患儿,SMC边缘整齐,厚度均匀,起于耻骨后面,分两束向后行经直肠两侧并在其后方交汇,形成漏斗样结构,直肠位于中央.结论 盆腔MR三维重建图像能清楚地显示骨盆解剖结构的关系,为ARM诊断和手术提供直观形态学依据,为虚拟手术奠定基础.

MR three-dimensional reconstruction in diagnosis and treatment of anorectal malformations

Objective To evaluate magnetic resonance images 3D reconstruction in anorectal malformations (ARM). Methods Magnetic resonance imaging examinations were performed on a 1.5-T magnet. Sagittal, coronal, and transverse turbo spin-echo (SE). T1-weighted and fast SE (FSE) T2-weighted images of the pelvic region were obtained in 28 children, and fat-suppression was applied in transversal and sagittal Tt Wl images were obtained in babies. A 3D reconstruction on a conventional personal computer (PC) was achieved with the assistance of 3D-Doctor software. The level and type of ARM and the developmental state of the Striated Muscle Complex (SMC) was analyzed with 3D re-construction image. Results The 3D images of the pelvic were confirmed by operation in 14 eases ARM (types: 5 high cases with rectal caecum located above SMCs, 4 intermediate with rectal caecum partially through SMCs, 5 low with rectal caecum fully through SMCs) and 14 control cases with rectal caecum penetrated SMCs. Three-dimensional reconstructed images displayed perfectly the anatomical relationships of the SMC and the rectal caecum in this space. The 3D configuration of the SMC was dif-ferent in each of the high and the low type eases. The malformation of SMCs in high type differed par-ticularly from the controls. Conclusions Pelvic MR 3D reconstructed images can show the dimensional anatomical relations of pelvis, bladder, urethra, rectum and SMC. It will help to provide morphological data for image diagnosis and operation for children with ARM.