Summary
Considered for a long time as a secondary mater with little contribution of its own, imaging in proctology has much evolved during the last decade and has contributed to improve the management of faecal incontinence and anorectal sepsis. Especially, endosonography (ES) and magnetic resonance imaging (MRI) play an increasing role in the anoperineal forms of Crohn’s disease (APCD). They are not systematically indicated but they turn out to be useful and even indispensable in difficult situations; complex and/or multi-operated suppuration, healing delay or persistence of discharge after operation, suspicion or observation of faecal incontinence, unexplained anorectal pain. Overall, MRI seems more reliable than ES in the detection of primary and secondary opening(s), fistulous pathways and collection(s). This results form better contrast resolution and the possibility of tridimensional analysis, keeping in mind that numerous technical improvements will keep ameliorating its performances. ES, however, is a reliable and well codified technique for the evaluation of sphincters. In addition, it has the advantage over MRI of being easy to access, cost-effective and fast and easy to perform. Finally, these two techniques seem to be complementary but, if one has to make a choice, selecting a radiologist with an excellent knowledge of anorectal anatomy and Crohn’s disease is still more important than the technique.