Dynamic MR Imaging of the Pelvic Floor: a Pictorial Review

Abstract

Pelvic floor dysfunctions involving some or all pelvic viscera are complex conditions that occur frequently and primarily affect adult women. Because abnormalities of the three pelvic compartments are frequently associated, a complete survey of the entire pelvis is necessary for optimal patient management, especially before surgical correction is attempted. With the increasing use of magnetic resonance (MR) imaging in assessing functional disorders of the pelvic floor, familiarity with normal imaging findings and features of pathologic conditions are important for radiologists. Dynamic MR imaging of the pelvic floor is an excellent tool for assessing functional disorders of the pelvic floor such as pelvic organ prolapse, outlet obstruction, and incontinence. Findings reported at dynamic MR imaging of the pelvic floor are valuable for selecting patients who are candidates for surgical treatment and for choosing the appropriate surgical approach. This pictorial essay reviews MR imaging findings of pelvic organ prolapse, fecal incontinence, and obstructed defecation. Supplemental material available at http://radiographics.rsnajnls.org/cgi/content/full/e35v1/DC1.

Erratum to: An International Urogynecological Association (IUGA) / International Continence Society (ICS) joint report on the terminology for female pelvic organ prolapse (POP)

“…It has been suggested that it may predict the severity of incontinence as well as the outcome of continence surgery since a weak sphincter will have a lower volume compared to a competent/continent urethral sphincter [39]. [42,43] (Figs. 22 and 23).…”

Standardization of dynamic magnetic resonance imaging measurements of pelvic organ prolapse: can the PICS line help?

“…The primary objective was to better select candidates for surgical intervention and choose the appropriate procedure in order to reduce recurrences by allowing accurate identification and objective measurement of prolapse and simultaneous topographic assessment of the pelvis at rest and straining [1][2][3][4][5]. MRI is particularly indicated in women with multi-compartment POP and in those who had undergone previous repair, as imaging can reveal more extensive prolapse than physical examination alone with detection rates similar to other conventional fluoroscopic and ultrasound methods [1,3,4]. Staging of POP using MRI has also been suggested by measuring the perpendicular distance between several reference points and lines in each compartment at rest and after straining [1][2][3][4][5].…”

“…MRI is particularly indicated in women with multi-compartment POP and in those who had undergone previous repair, as imaging can reveal more extensive prolapse than physical examination alone with detection rates similar to other conventional fluoroscopic and ultrasound methods [1,3,4]. Staging of POP using MRI has also been suggested by measuring the perpendicular distance between several reference points and lines in each compartment at rest and after straining [1][2][3][4][5]. The two most commonly used lines are one connecting the inferior aspect of the pubic symphysis to the last coccygeal joint, the pubococcygeal line (PCL), and one extending caudally along the long axis of the symphysis pubis, the midpubic line (MPL).…”

“…The two most commonly used lines are one connecting the inferior aspect of the pubic symphysis to the last coccygeal joint, the pubococcygeal line (PCL), and one extending caudally along the long axis of the symphysis pubis, the midpubic line (MPL). Several MRI staging systems have been published for both of these lines [1,3,4].Despite the widely accepted role of MRI in supplementing clinical evaluation and management of women with POP, this imaging modality has certain limitations. Most importantly, so far, there has been no standardized technique for performing MRI examination of the pelvis.…”

“…In fact, sagittal plane images of women with POP that are commonly displayed in the literature as if taken in the upright position had been made in the supine position [6]. A further major problem with MRI studies of the pelvis is the incomplete reproducibility and lack of standardization of the patient effort exerted during straining [3][4][5].The anatomical landmarks used for pelvic measurements are easily identified in MRI and this is expected to increase the validity of measurement [5]. The intra-and inter-observer reliability of most MRI measurements is, however, rarely described in POP studies [2].…”