الفهرس 
Anatomical ConsiderationsOnly 14 pages are availabe for public view
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Abstract
Anorectal malformations comprise a wide spectrum of disease affecting males and females and can involve malformations of the distal anus and rectum, as well as the urinary and genital tracts.
Diagnosis and early management has been refined by more thorough knowledge of the anatomy and physiology of the pelvic structures at birth.
The aims of the initial assessment are threefold:
1. To determine the level of the malformation in relation to the muscular sphincters and the site of any fistulous communications.
2. To determine the integrity of sphincters.
3. To document any associated anomalies that may affect survival.
Imaging studies play a key role in establishing and defining most, if not all, of these different aspects of anorectal malformations.
Since its introduction, MRI, because of its multiplanar imaging capability and superb tissue characterization, has proven to be the best modality to answer all the crucial questions.
Introduction of MRI imaging techniques opened new possibilities for evaluation of the pelvic structures and assessment of pelvic floor disorders. The capability of global visualization of all pelvic compartments and pelvic floor muscles, the enhanced tissue resolution of the pelvic organs, and its musculofascial support structures reinforced the interest of this method in the assessment of anorectal malformations.
Dynamic MRI of the pelvic floor can be very helpful to delineate not only anatomy but also the function of the continence organs. In these cases, the structure, quality, and function of the levator plate and the anal sphincter complex are of special interest for the pediatric surgeon.
The suggested protocol includes T2-weighted images in 3 planes, sagittal, coronal, and trans-axial followed by a dynamic study. The latter is performed in the mid-sagittal and coronal planes. The morphology, position, and function of the pelvic organs, and position and function of the pelvic floor muscles during different actions (relaxation, squeezing and defecation) can be analyzed.
Endoanal magnetic resonance (MR) imaging provides multiplanar, high-spatial-resolution demonstration of anal anatomy and a fine delineation of all sphincter muscles.
This technique is used to assess the appearances and patterns of scarring of the anal sphincter in infants and children after surgical correction of anorectal anomalies and to show the anatomic results of the transanal pull-through perineoplasty and the posterior sagittal anorectoplasty.
Therefore, both static and dynamic MRI examinations are essential in preoperative assessment for all cases with anorectal malformation in order to plane a good strategy for the reconstructive surgery.