新生儿盆底三维超声重建技术对先天性肛门直肠畸形的诊断价值

Diagnostic value of three-dimensional ultrasound reconstruction of pelvic floor in children with congenital anorectal malformation

目的:探讨新生儿盆底三维超声(three-dimensional ultrasound,3DUS)重建技术检测直肠盲端与周围肛提肌的关系,以及肛提肌厚度对诊断先天性肛门直肠畸形(congenital anorectal malformation,CARM)分型的价值。方法:采用盆底3DUS检查56例CARM,测量直肠盲端(distal rectal pouch)至肛门隐窝(perineum)的距离(P-P间距)、直肠盲端至肛提肌(levator ani muscle)的距离(P-L间距)、肛提肌厚度和肛门括约肌厚度,并采用磁共振成像(magnetic resonance imaging,MRI)评价其中42例CARM患儿盆底肌肉发育情况,分析3DUS对CARM的分型、比较3DUS与MRI测量CARM盆底肌肉各径线以及两者对CARM伴瘘管的诊断效能。结果:3DUS诊断测量P-P间距、P-L间距和肛提肌厚度各组间差异均有统计学意义(P均<0.05),3DUS测量56例CARM的P-P间距、肛提肌厚度和肛门括约肌厚度平均值分别为(10.65±4.62)、(2.14±0.40)和(1.36±0.41)mm,其中42例MRI检查测量P-P间距、肛提肌厚度和肛门括约肌厚度平均值分别为(11.47±4.84)、(2.12±0.36)和(1.32±0.38)mm,两者之间差异均无统计学意义(P均>0.05),与手术结果对照,3DUS提示诊断CARM伴瘘管28例,不伴瘘管7例,诊断灵敏度、特异度和准确率分别为65.1%、53.8%和62.5%,MRI提示诊断CARM伴瘘管21例,不伴瘘管5例,诊断灵敏度、特异度和准确率分别为63.6%、55.6%和61.9%,差异无统计学意义(χ^2=0.006,P=0.940)。结论:新生儿盆底三维超声重建技术可直观、立体地显示扩张直肠盲端与周围肛提肌的关系,准确测量肛提肌的厚度,完善了以往超声单一测定扩张直肠盲端距肛门隐窝距离的不足,可提高超声对CARM诊断分型的准确率。

Objective: To explore the value of pelvic floor three-dimensional ultrasound (3DUS) reconstruction in detecting the distal rectal pouch and the levator ani muscle around the rectum,and the thickness of levator ani muscle in the diagnosis of congenital anorectal malformation (CARM).Methods: Fifty-six cases of CARM were examined by pelvic floor 3DUS.The distance between distal rectal pouch and perineum (P-P distance),the distance between distal rectal pouch and levator ani muscle (P-L distance) and the thickness of levator ani muscle and sphincter ani muscle thickness were measured.Meanwhile,the development of pelvic floor muscles in 42 cases with CARM was evaluated by magnetic resonance imaging (MRI).The classification of CARM by 3DUS was analyzed,and the diameters of the pelvic floor muscles measured by 3DUS and MRI were compared.The diagnostic efficacy of the two methods for CARM with fistula was also discussed.Results: The P-P distance,P-L distance and the thickness of levator ani muscle between groups measured by 3DUS had statistical significance (P<0.05).The average P-P distance,levator ani muscle thickness and sphincter ani muscle thickness measured by 3DUS in 56 cases of CARM were (10.65±4.62),(2.14±0.40) and (1.36±0.41),respectively,and the average P-P distance,levator ani muscle thickness and sphincter ani muscle thickness measured by MRI in 42 cases were (11.47±4.84),(2.12±0.36) and (1.32±0.38) mm,respectively,there was no significant difference between the two groups (P>0.05).Compared with the results of operation,3DUS indicated that there were 28 cases with fistula and 7 cases without fistula,and the sensitivity,specificity and accuracy of diagnosis were 65.1%,53.8% and 62.5%,respectively.MRI indicated 21 cases with fistula and 5 cases without fistula.The sensitivity,specificity and accuracy of diagnosis were 63.6%,55.6% and 61.9%,respectively.There was no significant difference between the two groups (χ^2=0.006,P=0.940).Conclusion: Pelvic floor 3DUS reconstruction technology can visually and stereoscopically display the position of dilated distal rectal pouch and levator ani muscle around it,and accurately measure the thickness of levator ani muscle.It improves the shortcomings of the previous single ultrasound method for measuring the distance between dilated distal rectal pouch and perineum,and can improve the accuracy of ultrasound diagnosis and classification of CARM.