RESUMEN
<p><b>OBJECTIVE</b>To study the development of pelvic floor muscle, morphology and location of rectum and anal canal as well as morphology of spinal cord and sacrum based on pelvic magnetic resonance imaging(MRI) of children with fecal incontinence after anoplasty for anorectal malformation and to provide information on management of fecal incontinence.</p><p><b>METHODS</b>Clinical and MRI data of 34 children with fecal incontinence after anoplasty for anorectal malformation in the Second Hospital of Shangdong University from September 2009 to December 2011 were analyzed retrospectively. There were 21 males and 13 females with the age of 3 to 14 years old. All the children underwent MRI detection. The morphology of external anal sphincter, puborectalis, ani levator, rectum and anal canal as well as the development of spinal cord and sacrum were observed using 1.5T MR scanner, including routine axial view, coronal view and sagittal view.</p><p><b>RESULTS</b>MRI revealed that dysplasia of external anal sphincter, puborectalis and anilavatory were found in 18, 23 and 27 children, respectively. MRI also showed ectopia of rectum(n=6), dilation of rectum(n=12), increased anorectal angle(n=11), fat tissue around the anal canal(n=5), tethered cord syndrome(n=2), Currarino syndrome(n=2), sacrum dysplasia(n=11); and rectourethral fistula(n=2). The above MRI findings were confirmed by operation and clinical practice.</p><p><b>CONCLUSIONS</b>MRI can provide clear morphology of external anal sphincter, puborectalis and ani lavatory, and location of rectum and anal canal as well as the development of spinal cord and sacrum. MRI is a valuable method to evaluate the children with fecal incontinence after anoplasty.</p>