Endoanal magnetic resonance imaging in faecal incontinence

Purpose. Within the recent years several studies have been performed to determine the value of endoanal magnetic resonance imaging (MRI) in faecal incontinence. Methods. MRI is performed using a 0.5 - 1.5T unit. A surface coil with a maximum diameter of 19 mm is placed in the anal canal. T2* 3D gradient-echo-sequences and T2-weighted turbo-spin-echo-sequences in coronal,axial und sagittal orientation are acquired. Results. Compared to endoanal ultrasound (EUS), which is the gold standard for diagnosis in faecal incontinence, endoanal MRI is better in visualization of the external sphincter. The accurate delineation of the external sphincter has led to the possibility to evaluate sphincter atrophy. Preliminary results have shown,that endoanal MRI has an accuracy of 90-95% in the demonstration of lesions in the external sphincter. In detection of lesions of the internal sphincter EUS is still superior to endoanal MRI. Conclusion. EUS and endoanal MRI are currently the optimal imaging techniques for faecal incontinenc,with the advantage of detecting external sphincter atrophy with endoanal MRI.