You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is A neonate is brought with history of not having passed meconium. On examination there is no anal opening but a dimple. Investigation of choice would be? and explain in detail?
MRI, due to excellent inherent soft tissue contrast,is best to define the relationship of the atretic segment to the levator ani pelvic sling and the integrity of sphincters and their nerve supply (anorectal malformation).