Practical MR Imaging of Female Pelvic Floor Weakness

Pelvic floor weakness is common in middle-aged and elderly parous women and is often associated with stress incontinence, uterine prolapse, constipation, and incomplete defecation. Most patients with incontinence and minimal pelvic floor weakness can be treated based on physical examination and basic urodynamic findings. However, in women with symptoms of multicompartment involvement for whom a complex repair is planned or who have undergone previous repairs, magnetic resonance (MR) imaging can be a useful preoperative planning tool. The MR imaging evaluation is performed with the patient in the supine position, without contrast agents, and within 15 minutes. A multicoil array and a rapid half-Fourier T2-weighted imaging sequence are used to obtain sagittal images while the patient is at rest and during pelvic strain, followed by axial images. On these images, the radiologist identifies the pubococcygeal line (which represents the level of the pelvic floor), the H and M lines (which are helpful for confirming pelvic floor laxity), and the angle of the levator plate with the pubococcygeal line (which is helpful for identifying small bowel prolapse). In the appropriate patient, MR images provide relatively easy three-dimensional conceptualization of the pelvic floor and can significantly influence treatment planning.