Abstract
Purpose: To evaluate the spectrum of magnetic resonance imaging (MRI) findings in pediatric
patients with anorectal malformation (ARM) and compare the accuracy of MRI and distal
cologram (DC) findings using surgery as reference standard. Materials and Methods: Thirty pediatric patients of age less than 14 years (19 boys and 11 girls) with ARM
underwent preoperative MRI. MRI images were evaluated for the level of rectal pouch
in relation to the pelvic floor, fistula, and development of sphincter muscle complex
(SMC). Associated spinal and other anomalies in lumbar region and pelvis were also
evaluated.DC was done in 26 patients who underwent colostomy. Ultrasound of abdomen
and pelvis was also done for associated anomalies. Results: Overall accuracy of MRI and DC to detect the exact level of rectal pouch including
cloacal malformation was 93.33% and 76.9% respectively. MRI and DC could correctly
identify presence or absence of fistula in 76.6% and 76.9% cases respectively. MRI
and DC correctly identified the anatomy of fistula in 76% and 65% cases respectively.
On MRI, correlation of development of levator ani and puborectalis with the level
of rectal pouch as found on surgery was significant (P = 0.008; 0.024 respectively). Subjective assessment of sphincter muscle development
on MRI correlated well with the surgical assessment [P = 0.019 and 0.016 for puborectalis
and external anal sphincter (EAS) respectively]. Lumbosacral spine anomalies were
present in 33.3% of patients and were most common in high type of ARM. Vesicoureteric
reflux and renal agenesis were the most common renal and urinary tract anomalies and
were present in 40% of cases. Conclusion: MRI allows reliable preoperative evaluation of ARM and should be considered as a
complementary imaging modality for preoperative imaging in ARM.
Keywords
Anorectal malformation - distal cologram - MRI
