Magnetic resonance imaging of perianal Crohn disease in children.

Perianal penetrating complications of Crohn disease are among the most important causes of symptoms in the pediatric population. High-quality diagnostic imaging of the perianal region is crucial for treatment planning and therapeutic response assessment. MRI, with its absence of ionizing radiation and high soft-tissue resolution, provides an excellent noninvasive tool for evaluation of perianal fistulae and associated abscesses, as well as their anatomical relationship to the anal sphincter complex. In this review we discuss the role of MRI in initial diagnosis and follow-up of perianal fistulizing Crohn disease in the pediatric population.