In a multiparous patient with stress urinary incontinence, vaginal bulging, incomplete defecation, and suspected pelvic organ prolapse, what is the role of imaging?
In patients with suspected pelvic organ prolapse, dynamic cine MRI can be obtained to assess pelvic floor function. Patients are imaged dynamically before and after Valsalva and other maneuvers that can potentially confirm diagnosis in patients with suspected pelvic organ prolapse. Sometimes rectal and vaginal contrast is used in combination with Valsalva maneuvers to try to reproduce the patient’s symptoms. Imaging can quantify the degree of pelvic organ prolapse in all three compartments (anterior, middle, and posterior) during Valsalva. Proposed MRI organ prolapse grading systems utilize reference lines drawn between normal anatomic structures on sagittal images (e.g., the pubococcygeal line [PCL] drawn from the inferior margin of the pubic symphysis to the last horizontal sacrococcygeal joint, the H line drawn from the inferior pubic symphysis to the posterior anorectal junction which demarcates the urogenital hiatus; and the M line drawn from the posterior end of the H line to (and perpendicular to) the PCL which serves as a reference for the pelvic floor descent) to estimate the degree of organ dysfunction. However, physical examination staging with the pelvic organ prolapse quantification (POP-Q) system (which uses the vaginal hymen as a point of reference) has become the clinical reference standard for evaluating patients with organ prolapse because of its interobserver and intraobserver reliability. Fluoroscopic imaging studies (such as with voiding cystourethrography [VCUG], double balloon urethrography, and defecography) were used more frequently in the past, although MRI and US are now used more commonly in conjunction with physical examination and other functional urodynamic imaging techniques.