Fluoroscopic defecography: how to perform and interpret

Fluoroscopic defecography: how to perform and interpret Poster No.: C-1469 Congress: ECR 2016 Type: Educational Exhibit Authors: A. C. Silva, D. D. T. Maglinte ; Porto/PT, Indianapolis, IN/US Keywords: Gastrointestinal tract, Fluoroscopy, Defecography, Education and training DOI: 10.1594/ecr2016/C-1469 1 2 1 2 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 39

Learning objectives 1. Review the indications for fluoroscopic defecography 2. Learn "step-by-step" how to perform fluoroscopic defecography 3. Provide imaging comparison between fluoroscopic and MR defecography illustrating the strengths and shortcomings of each examination 4. Learn to interpret the imaging findings of anorectal dysfunction and to stage pelvic organ prolapse using reference points used in clinical quantification Background Functional pelvic floor abnormalities represent a common health care problem. It is estimated that approximately 15% of older multiparous women suffer from variable degrees of pelvic support defect. These conditions often impact significantly the quality of life and result in a variety of symptoms leading often to psychological distress and work absenteeism. PELVIC FLOOR ANATOMY The pelvic floor is a single unit of organs and osseous-muscle-ligament and fascial components that work in an interactive and coordinated way. ( Fig. 1 on page 3 ) The pelvis is considered as being composed of three Functional Compartments the Anterior, Middle and Posterior and three Levels of Support, made by the Endopelvic Fáscia, Levator Ani and Perineal Membrane. ( Fig. 2 on page 4 ) Nevertheless this classification is only for descriptive purposes as its assessment and treatment are approached simultaneously. PHYSIOPATHOLOGY AND CLINICAL PRESENTATION Page 2 of 39

Epidemiologic studies in different populations have evaluated the risk factors in the development of pelvic floor dysfunction concluding that they are multifactorial combining epidemiological factors (female gender, old age, high IBM and nutritional deficits) with obstetrical/ gynaecological, gastrointestinal and psychological risk factors. Clinical presentation of these disorders depends on what functional compartment is involved and how many compartments are affected and their severity. (Table 1 on page 6) The majority of patients have multiple compartment defects and therefore the clinical presentation may be variable. Even if clinically these patients do not present with symptoms of defects from a combination of compartments, the existence of such defects if demonstrated by imaging studies should be taken into consideration by the physician particularly if the patient is to undergo surgical management. If a comprehensive repair is not done, coexisting asymptomatic support defects may become symptomatic in a relatively short time. Functional imaging is therefore important to diagnose associated compartment defects and in those with physical examination findings not consistent with patients complaints. A successful outcome not only depends on the surgeon s skill but also relies heavily on the preoperative recognition of all pelvic floor compartments defects to allow the surgeon to tailor the operative strategy to prevent recurrences. Images for this section: Page 3 of 39

Fig. 1: Sagital section of the female cadeveric pelvis: Lateral aspect. Page 4 of 39

Fig. 2: Cadaveric female pelvis with imaging correlation of the functional compartments and levels of support. Green - anterior compartment; Pink - middle compartment; Brown - posterior compartment. Level 1: Line drawn at the upper third of vagina and cervix. Made by the long suspensory fibers of the paracolpum - cardinal ligament and uterosacral ligament complex. Supports the uterus and upper part of the vagina. The pelvic ligaments are not classic ligaments but thickening of retroperitoneal fascia and consists primarily of blood, lymphatic vessels nerves and fatty connective tissue. Anatomists call the retroperitoneal fascia as Subserous Fascia whereas surgeons refer to this fascial layer as endopelvic fascia (dotted pink line). It is to thin to be recognized at imaging but its integrity is inferred by the posterior flat appearance of the bladder wall. Level 2: Line drawn at the middle part of the vagina. It is supported by the levator ani muscle (pubococcygeus, iliococcygeus, puborectalis) that with the endopelvic fascia attach laterally to the arcus tendineous, the fascia pelvis and by the coccygeus (also called ischiococcygeus); The iliococcygeus has a mainly supportive function; the pubococcygeus and puborectalis (pubovisceral muscles) have a sphincteric function. The puborectalis is a thick muscle considered by some part of the pubococcygeus that instead of inserting in the coccyx loops around the rectum and moves dorsoventrally; the iliococcygeus has variable thickness (mean 2.9 mm, SD 0.8mm) and moves craniocaudally. Gaps in the diaphragmatic portion of the iliococcygeus are a normal finding. Level 3: Line drawn at the lower part of the vagina. Is supported by the Page 5 of 39

urogenital diaphragm (strong muscular membrane that occupies the area between the symphysis pubis and ischial tuberosities), perineal body, urethral and anal sphincters, urethral suspensory ligaments and bulbocavernosus muscles. At this level resides the mechanisms that takes part in the urinary continence (urethral striate sphincter, pubourethral, periurethral and paraurethral ligaments) and the urogenital sphincter. The puborectalis also takes part in urinary continence. Table 1: Correlation between symptons and pelvic functional compartments in pelvic floor disorders. Page 6 of 39

Findings and procedure details INDICATIONS FOR DEFECOGRAPHY: Fluoroscopic defecography/proctography was conventionally used to document the evacuation process and evaluate functional and anatomical anorectal disorders as chronic constipation, fecal incontinence or suspected rectal prolapse. However due to the recognition of the association of defecatory disorders with other pelvic organ prolapse, the need to evaluate the pelvic floor as a unit has arisen and defecography has been extended to include not only evaluation of defecation disorders but also the rest of the pelvic viscera by opacifying the small bowel, vagina and the urinary bladder, the so called "dynamic cystocolpoproctography" (DCP). This allowed to study patients with complaints related to the other compartments (Table 1 on page 13 ) as urinary incontinence, organ prolapse and pelvic discomfort. Nevertheless pelvic floor anatomy is complex and DCP does not show the anatomic details that pelvic MRI provides. Technical advances allowing acquisition of dynamic rapid MRI sequences applied to pelvic floor imaging provide objective information about disorders of the different compartments of the pelvis without ionizing radiation exposure. However, because most of these exams are made supine which has less gravitational influence than sitting, underestimation of pelvic floor descent, intussusceptions and even lack of detection of enteroceles or sigmoidocoeles can occur. Additionally patients are frequently asymptomatic in the supine position, an unnatural position which makes an embarrassing examination less acceptable. In order to choose the most suitable treatment for pelvic floor dysfunctions, referring physicians requires a complete clinical investigation and functional examination techniques capable of identifying anatomical and functional abnormalities. ( Table 2 on page 14 ) PERFORMING THE EXAM: TECHNICAL REQUIREMENTS To perform dynamic cystocolpoproctography you will need: ( Fig. 3 on page 14 ) 1. Barium sulfate suspension (to opacify the small bowel) Page 7 of 39

2. Barium sulfate paste (to opacify the rectum) 3. 60 ml syringe with catheter tip 4. Lidocain hydrochloride jelly 2% 5. Rectal tube 6. 6-8 Fr paediatric feeding tube or 8 or 10 Fr Foley catheter (to opacify the bladder) 7. Iodine contrast (to opacify the bladder) 8. Ultrasound gel mixed with barium (to opacify the vagina) 9. Opaque markers (to perform measurements) 10. Ring forceps (Optional. To maintain the rectal tube in place when inserting the paste) You will also need: ( Fig. 4 on page 15 ) 1. Fluoroscope 2. Radiolucent Commode 3. Footrest PERFORMING THE EXAM: STEP-BY-STEP Dulcolax suppository 30 min/1 hour prior to imaging. STEP 1: Opacification of small bowel: Drinks 200 cc of barium solution 45 to 60 min prior to the examination; STEP 2: Patient sits in the commode and lateral views are taken at rest with the opaque marker taped to the back in the midline body to help with the measurements later performed. Bony landmarks are recognized. STEP 3: Place patient supine in stretcher and perform: Page 8 of 39

Retrograde Cystography: Insert 100 cc of iodinated contrast with a 6-8 Fr pediatric feeding tube or 8 or 10 Fr Foley catheter. Tape it to the inner thigh and leave it during the rest of the exam; Vaginal Opacification: Introduce 20 cc of ultrasound gel mixed with barium. Hold it with a 4-inch gauze square placed between the labia along the length of the urogenital hiatus; Patient turns to left decubitus. Perform a digital rectal exam to evaluate the anal sphincter (hypotonic, normotonic or hypertonic) and to exclude rectal mass obstructing anorectal junction; Rectal Opacification: Insert 30-50 ml of high density barium suspension to coat the rectal mucosa followed by 250 cc of barium past. Stop whenever the patient states that cannot tolerate it anymore, whatever the amount inserted. STEP 4: Obtain pre-evacuation and evacuation images with patient seated in the commode during: Rest "Squeezing" the pelvic floor muscles "Straining" without voiding Dynamic evacuation (30 sec) STEP 5: Obtain Post-defecation at Rest and Maximum Straining; STEP 6: Obtain Post-toilet/catheter bladder drainage at Rest and Maximum Straining RELEVANT PELVIC ANATOMY AND LANDMARKS Image analysis starts by identifying the anatomy and landmarks included in the spot imagens. Starting with the lateral pelvic spot image at rest the opacified small bowel, bladder, vagina and rectum must be identified and included. ( Fig. 5 on page 16 ) Afterwards recognize and measure the: Page 9 of 39

1. Pubococcygeal line (PCL): imaginary line connecting the inferior margin of the pubis and last coccygeal joint. Used as a landmark to evaluate pelvic floor movement; 2. Anorectal junction (ARJ): Cross point formed by a line along the longitudinal axis of the anal canal and posterior rectal border. Usually projects 3 cm inferior to the PCL at rest; 3. Anorectal angle (ARA): angle between longitudinal axis of anal canal and posterior rectal border (Normal: 70º-140º). It reflects the puborectalis muscle activity becoming more acute during the "squeeze" (75º-95º) and more obtuse during "strain" (100º-180º). ( Fig. 6 on page 16 ) NORMAL FINDINGS ON DEFECOGRAPHY Normal defecation involves an interaction between the colon and the rectum. The urge to defecate is initiated by rectal distention from high-amplitude propagating waves that move fecal contents into the rectum which is distended resulting in the relaxation of the internal anal sphincter. Evacuation is initiated by abdominal straining and voluntary pelvic floor relaxation. The anal canal opens and the rectum is squeezed from abdominal contraction. The initiating movement for defecation is pelvic floor descent, which is defined as the descent of the anorectal junction (ARJ) from rest to maximum widening of the anal canal. The canal opens completely and in a second or so the rectum starts to empty. Emptying is rapid usually under 30 sec. When the patient stops straining, tone returns to the internal anal sphincter and levator ani so the anal canal closes and the AR angle becomes more acute; the pelvic floor and ARJ junction elevate to their normal resting position.( Fig. 7 on page 17 ) ABNORMAL FINDINGS ON DEFECOGRAPHY Abnormal functional and morphological findings detected during defecography that should be recognized, characterized and quantified are. Pelvic Floor dyssynergy (anismus): Page 10 of 39

Functional disorder characterized by prolonged and or incomplete evacuation of contrast material. The patients suffer from a failure of coordination of the abdominal and pelvic floor muscles involved in defecation. The examination shows a significant increase in evacuation time, decrease in percentage evacuated and reduced canal width and marked delay in widening of the anal canal. ( Fig. 8 on page 18 ) Rectocele Defined as an outpouching of the rectal wall most commonly the anterior wall through the posterior vaginal wall that occurs during evacuation. They result from defects in the integrity of the rectovaginal septum due to weakening of it with herniation of the rectal wall into the vaginal lumen. Patients become symptomatic when the leading edge of a prolapsing pelvic organ is close to or displaces the plane of the hymen (line crossing the posterior margin of the vaginal fourchetts parallel to the plane of the anterior cortex of the pubic bones) not necessarily correlating with its size. ( Fig. 9 on page 19 ) Intussusception and rectal prolapse Defined as an infolding of the rectal mucosa or wall that if protrudes through the anal canal, below anal verge it is termed rectal prolapse. It can be limited to the rectum (intrarectal or rectorectal- clinically insignificant but can progress if etiology not corrected) or can extend to the anal canal (rectoanal or so called internal prolapse). It can either involve the mucosa (more frequent in rectorectal) or the full thickness of the rectal wall, usually the latter. ( Fig. 10 on page 19 ) Studies showed that this finding is usually missed or underestimated at MR Defecography because of the lack of the gravity effect and the mucosa not seen as well. ( Fig. 11 on page 20 & Fig. 12 on page 21 ; Fig. 13 on page 22 & Fig. 14 on page 23 ) Enterocele, sigmoidocele, peritonocele Enterocele - Herniation of the small bowel either into the posterior peritoneal cul-de-sac in the rectovaginal space or into the vagina itself. Page 11 of 39

Usually become more evident at the end of evacuation and after complete voiding because of the space occupied by other distended organs. ( Fig. 15 on page 24 & Fig. 16 on page 25 ) Sigmoidocele - Is a redundancy of the sigmoid colon that extends caudally into the culde-sac. Less common than enteroceles and in order to be recognized full opacification of the sigmoid is advised. Nevertheless it can be recognized as widening of the rectovaginal septum, air seen with the fecal residues. ( Fig. 17 on page 26 & Fig. 18 on page 27 ) Peritoneocele - Is the herniation of the cul-de-sac, or an extension of the rectouterine excavation below the upper third of the vagina. As they usually contain small bowel its opacification is paramount for its diagnosis. ( Fig. 19 on page 28 & Fig. 20 on page 29 & Fig. 21 on page 30 ) As it occurs with intussusceptions it is the experience of the authors that these entities are often missed or understaged at MR Defecography due to the lack of gravity and delineation of the mucosa. Descending perineum syndrome Defined as pathological descensus of the pelvic floor at rest or at straining caudal to the PCL. Usually all three compartments of the pelvic floor are involved but also a descent only of the anorectum can occur. The etiology is multifactorial and includes chronic straining with muscle weakness and stretching of the elastic tissue in the fascial supports. ( Fig. 22 on page 31 & Fig. 23 on page 32 ) QUANTIFICATION OF THE ABNORMAL FINDINGS Several quantification systems can be used either on dynamic cystocolpoproctography or dynamic MRI. Three-compartment model Page 12 of 39

The pubococcygeal line (PCL) is the reference line; Distance of the bladder base, vaginal vault/cervix and the anorectal junction (AJR) is measured at 90º angle at rest, squeeze, strain, during evacuation and post evacuation and post toilet; Measurements should be done at maximal organ descent ( Fig. 24 on page 33 ). HMO System Distinguishes pelvic organ prolapse and relaxation; H-line (hiatal widening) and M line (pelvic organ descent) as well as as the PCL are marked ( Fig. 25 on page 34 ); Pelvic floor prolapse is defined as any organ that descend beyhond the H line (O). Midpubic Line This was proposed as a correlate to the plane of the hymen in cadavers. However further studies demonstrated that it does not correspond to the plane of the hymen in vivo. Pelvic Organ Prolapse Quantification system (POP-Q) Uses the Plane of the Hymen as a reference line, the same as the International Continent Society Pelvic Organ Quantification (ICS POP Q) ( Fig. 26 on page 35 ). Images for this section: Page 13 of 39

Table 1: Correlation between symptons and pelvic functional compartments in pelvic floor disorders. Table 2: Clinical algorithm on when to perform a pelvic examination Page 14 of 39

Fig. 3: Technical requirements to perform dynamic colpocystoproctography Fig. 4: Technical requirements to perform Dynamic colpocystoproctography. 1. Fluroscope; 2. Radiolucent comode; 3. Foot rest. Page 15 of 39

Fig. 5: Relevant pelvic anatomy. Page 16 of 39

Fig. 6: Relevant pelvic anatomy. Symphysis Pubis (dotted pink line). Pubococcygeal line(pcl) (red dotted line); Anorectal junction (*) Puborectalis muscle impression (pink crescent); Small bowel loops (SBL); Anorectal angle (ARA) (green). Page 17 of 39

Fig. 7: Normal findings on defecography Fig. 8: Anismus. The evacuation sequence video shows the usual findings of this disorders namely prolonged evacuation time (>30sec), impared verticalization of the anorectum canal and decrease in the percentage of contrast material evacuated. Page 18 of 39

Fig. 9: Rectocele noticed during evacuation (asterix). An anterior rectal wall outpouching is dislocating anteriorly the vagina (arrows) which is horizontal and the plane of the hymen. Some barium retention is also noted. Page 19 of 39

Fig. 10: Intussusception. During evacuation full thickeness wall infolding of the rectum is noted (arrows) that extend to the canal anal (open arrow). Page 20 of 39

Fig. 11: Intussusception in defecography and MRI of the same patient. Notice that the intussusception is much more evident at defecography being characterized by envolving full thickness wall and extending, but not protruding, the anal canal. At MRI only mucosal intussusception is noted. This findings is therefore underestimated at this examination Page 21 of 39

Fig. 12: Intussusception in defecography and MRI of the same patient. Notice that the intussusception is much more evident at defecography being characterized by envolving full thickness wall and extending, but not protruding, the anal canal. At MRI only mucosal intussusception is noted. This findings is therefore underestimated at this examination Page 22 of 39

Fig. 13: Circunferential rectal wall intussusception is present reaching the anal canal but without external prolapse. An anterior rectocele is also present that retains small amount of contrast. Page 23 of 39

Fig. 14: Dynamic MRI of the same patient showed at fig 13 failed to demonstrate the intussusception during evacuation. The most striking finding is the cystocele demonstrated by the base of the bladder below the PCL. Page 24 of 39

Fig. 15: Enterocele - Defecography and MRI of the same patient. At defecography an enterocele is started to be noted at the end of defecation. Nevertheless its diagnosis is much evident at the post-evacuation and post -WC series. Intussusception is also present (arrow). MRI of the same patient falied to diagnose the enterocele Page 25 of 39

Fig. 16: MRI of the same patient showed at fig 15 failed to diagnose the enterocele. Page 26 of 39

Fig. 17: Defecography during evacuation sequence shows descending perineum and at the end of evacuation a small sigmoidocele (asterix). This finding is more notorious in the post evacuation sequence at maximal strain, as demonstrated. Page 27 of 39

Fig. 18: Dynamic MR of the same patient shown at figure 17 failed to demonstrate the presence of a sigmoidocele. Only an anterior, clinically insignificant, rectocele is present. Page 28 of 39

Fig. 19: Peritonecele can be perceived in the evacuation sequence of defecography as a lucent area that insinuates into the recto-vaginal septum (double arrow) pushing the rectum. An intussuscetion and small rectocele are also present. Page 29 of 39

Fig. 20: Dynamic MRI during strainnig. Fat can be perceived insinuating into the rectalvaginal space. Page 30 of 39

Fig. 21: Dynamic MR during evacuation. A peritonocele of fat is clearly occupying the rectal-vaginal space being more proeminete during this sequence compared to just strainning. Page 31 of 39

Fig. 22: Descending perineum syndrome. Notice the abnormally low position of the ARJ and the vaginal cul-de-sac, in the beginning of the evacuation sequence compared to the ischiopubic tuberosities. This finding is aggravated with the strainning of the evacuation defining this condition. An insinuated enterocele is also noted. Page 32 of 39

Fig. 23: Dynamic MR during evacuation sequence shows marked descending perineum when related to the PCL. All three compartments of the pelvis are involved. Page 33 of 39

Fig. 24: Three compartment model. Abnormal descent of the ARJ (asterix) and the bladder base is noted. The grade follows the "rule of 3" - mild <3cm; moderate < 6cm; severe >6 cm. Fig. 25: HMO System. The H line that represents hiatal widening is abnormal (> 5cm) and also the M line that represents hiatal descent (> 2 cm). Page 34 of 39

Fig. 26: Imaging POP Q system. A line crossing the posterior margin of the vaginal fourchettes parallel to the plane of the anterior cortex of the pubic bones determines the plane of the hymen in vivo. This system is meant to complement the ICS POP Q and not to compete with it. Page 35 of 39

Conclusion Pelvic floor disorders represent an increasing and complex clinical problem, "an epidemic nobody talks about" due to the aging of the female population and other factors. The treatment of pelvic floor dysfunction is becoming increasingly dependent on preoperative imaging. Thorough diagnostic characterization of which or how many compartments are affected is paramount in order to plan the appropriate management approach that may require a multidisciplinary team. Recent progress in imaging conveys improved structural information without associated radiation when using appropriate MR technology. However fluoroscopic examinations maintain an important role in the functional diagnostic information it provides allowing diagnosis of the full extent and multicompartment association of pelvic organ prolapses which is useful information when planning the appropriate management/surgical approach. The need to use a standardized, reliable and clinically understandable method of quantification has become more obvious with the increasing rate of dissemination of scientific information and professional interchanges. Personal information Ana Catarina Silva, M.D Radiology attending at Unidade Local de Saúde de Matosinhos, EPE, Portugal, since 2009. Fellowship on GI radiology at Hospital of the University of Pennsylvania in 2005 and at the Indiana University Hospital in 2007 to perform CT enteroclysis and colpocystoproctography. Recent publications: Book Chapter: Page 36 of 39

The role of CTE/Barium Entero. Elsevierclysis in Crohn s disease (in: Crohn s Disease: Current concepts. Rajesh, Sinha. Springer) Book Chapter: Computed TomographyEnteroclysis (In: Textbook of Gastroenterology Radiology; Gore & Levine, 4th ed. Elsevier) Article: Pelvic Floor Disorders: What s the best test? Ana Catarina Silva, Dean Maglinte. Abdominal Imaging 10/2013; 38(6). DOI:10.1007/s00261-013-0039-z References Maglinte DD, Bartram CI, Hale DA, et al. (2011) Functional imaging of the pelvic floor. Radiology 258(1):23-39 Maglinte DD, Kelvin FM, Fitzgerald K, Hale DS, Benson JT (1999) Association of compartment defects in pelvic floor dysfunction. AJR Am J Roentgenol 172(2):439-444 Jelovsek JE, Maher C, Barber MD (2007) Pelvic organ prolapse. Lancet 369:1027 Mant J, Painter R, Vessey M (1997) Epidemiology of genital prolapse: observations from the Oxford Family Planning Association Study. Br J Obstet Gynaecol 104:579 Tinelli A, Malvasi A, Rahimi S, et al. (2010) Age-related pelvic floor modifications and prolapse risk factors in postmenopausal women. Menopause 17:204 Klingele CJ, Bharucha AE, Fletcher JG, et al. (2005) Pelvic organ prolapse in defecatory disorders. Obstet Gynecol 106:31519. Maglinte DD, Kelvin FM, Hale DS, Benson JT (1997) Dynamic cystoproctography: a unifying diagnostic approach to pelvic floor and anorectal dysfunction. AJR Am J Roentgenol 169(3):759-767 Page 37 of 39

Stoker J, Halligan S, Bartram CI (2001) Pelvic floor imaging. Radiology 218(3):621-641 Kelvin FM, Maglinte DD, Benson JT (1994) Evacuation proctography (defecography): an aid to the investigation of pelvic floor disorders. Obstet Gynecol 83(2):307-314 Kelvin FM, Maglinte DD (1997) Dynamic cystoproctography of female pelvic floor defects and their interrelationships. AJR Am J Roentgenol 169(3):769-77439. Singh K, Reid WM, Berger LA (2001) Assessment and grading of pelvic organ prolapse by use of dynamic magnetic resonance imaging. Am J Obstet Gynecol 185(1):71-77 Silva, Ana C. Maglinte Dean (2013) Pelvic Floor Disorders: What s the best test? Abdom Imaging 38:1391-1408 Halligan S, Bartram CI, Park HJ, Kamm MA (1995) Proctographic features of anismus. Radiology 197(3):679-682 Halligan S, Malouf A, Bartram CI, et al. (2001) Predictive value of impaired evacuation at proctography in diagnosing anismus. AJR Am J Roentgenol 177(3):633-636 Stoker J, Bartram CI, Halligan S (2002) Imaging of the posterior pelvic floor. Eur Radiol 12(4):779-788 Kenton K, Shott S, Brubaker L (1999) The anatomic and functional variability of rectoceles in women. Int Urogynecol J Pelvic Floor Dysfunct 10(2):96-9948. McGee SG, Bartram CI (1993) Intra-anal intussusception: diagnosis by posteroanterior stress proctography. Abdom Imaging 18(2):136-140 Pomerri F, Zuliani M, Mazza C, Villarejo F, Scopece A (2001) Defecographic measurements of rectal intussusception and prolapse in patients and in asymptomatic subjects. AJR Am J Roentgenol 176(3):641-645 Page 38 of 39

Pannu HK, Kaufman HS, Cundiff GW, et al. (2000) Dynamic MR imaging of pelvic organ prolapse: spectrum of abnormalities. RadioGraphics 20(6):1567-1582 Parks AG, Porter NH, Hardcastle J (1966) The syndrome of the descending perineum. Proc R Soc Med 59(6):477-48264 Maglinte DDT, Hale DS, Sandrasegaran K (2013) Comparison between dynamic cystocolpoproctography and dynamic pelvic floor MRI: pros and cons: which is the ''functional'' examination for anorectal and pelvic floor dysfunction? Abdom Imaging 38(5):952-973 Comiter CV, Vasavada SP, Barbaric ZL, Gousse AE, Raz S (1999) Grading pelvic prolapse and pelvic floor relaxation using dynamic magnetic resonance imaging. Urology 54(3):454-457 Singh K, Reid WM, Berger LA (2001) Assessment and grading of pelvic organ prolapse by use of dynamic magnetic resonance imaging. Am J Obstet Gynecol 185(1):71-77 Page 39 of 39