title: MR-defecography in obstructed defecation syndrome (ODS): technique, diagnostic criteria and grading.
abstract: BACKGROUND
  The aim of this study was to evaluate the use of a magnetic resonance (MR)-based classification system of obstructive defecation syndrome (ODS) to guide physicians in patient management.
  
  
  METHODS
  The medical records and imaging series of 105 consecutive patients (90 female, 15 male, aged 21-78 years, mean age 46.1 ± 5.1 years) referred to our center between April 2011 and January 2012 for symptoms of ODS were retrospectively examined. After history taking and a complete clinical examination, patients underwent MR imaging according to a standard protocol using a 0.35 T permanent field, horizontally oriented open-configuration magnet. Static and dynamic MR-defecography was performed using recognized parameters and well-established diagnostic criteria.
  
  
  RESULTS
  Sixty-seven out of 105 (64 %) patients found the prone position more comfortable for the evacuation of rectal contrast while 10/105 (9.5 %) were unable to empty their rectum despite repeated attempts. Increased hiatus size, anterior rectocele and focal or extensive defects of the levator ani muscle were the most frequent abnormalities (67.6, 60.0 and 51.4 %, respectively). An MR-based classification was developed based on the combinations of abnormalities found: Grade 1 = functional abnormality, including paradoxical contraction of the puborectalis muscle, without anatomical defect affecting the musculo-fascial structures; Grade 2 = functional defect associated with a minor anatomical defect such as rectocele ≤ 2 cm in size and/or first-degree intussusception; Grade 3 = severe defects confined to the posterior anatomical compartment, including >2 cm rectocele, second- or higher-degree intussusception, full-thickness external rectal prolapse, poor mesorectal posterior fixation, rectal descent >5 cm, levator ani muscle rupture, ballooning of the levator hiatus and focal detachment of the endopelvic fascia; Grade 4 = combined defects of two or three pelvic floor compartments, including cystocele, hysterocele, enlarged urogenital hiatus, fascial tears enterocele or peritoneocele; Grade 5 = changes after failed surgical repair abscess/sinus tracts, rectal pockets, anastomotic strictures, small uncompliant rectum, kinking and/or lateral shift of supra-anastomotic portion and pudendal nerve entrapment.
  
  
  CONCLUSIONS
  According to our classification, Grades 1 and 2 may be amenable to conservative therapy; Grade 3 may require surgical intervention by a coloproctologist; Grade 4 would need a combined urogynecological and coloproctological approach; and Grade 5 may require an even more complex multidisciplinary approach. Validation studies are needed to assess whether this MR-based classification system leads to a better management of patients with ODS.
authors.affiliation: Pelvic Floor Imaging Centre-Clinica Villa Silvia, Via Marche 24, 60019, Senigallia, AN, Italy, vittorio.piloni@libero.it.
authors.forename: V
authors.initials: V
authors.lastname: Piloni
authors.forename: P
authors.initials: P
authors.lastname: Tosi
authors.forename: M
authors.initials: M
authors.lastname: Vernelli
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003248:Constipation / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D016208:Databases, Factual; D019841:Defecography / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007415:Intestinal Obstruction / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012002:Rectal Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013577:Syndrome; D055815:Young Adult
chemical_list: D003287:Contrast Media
references.citation: Eur J Radiol. 2005 Mar;53(3):410-6
references.pmid: 15741014
references.citation: Gastrointest Radiol. 1988;13(1):72-80
references.pmid: 3350272
references.citation: Eur Radiol. 1997;7(8):1309-17
references.pmid: 9377520
references.citation: Am J Obstet Gynecol. 2001 May;184(6):1156-63
references.pmid: 11349182
references.citation: Dis Colon Rectum. 2008 Nov;51(11):1611-8
references.pmid: 18642046
references.citation: Gastrointest Radiol. 1984;9(3):247-51
references.pmid: 6468862
references.citation: Ultrasound Obstet Gynecol. 2005 Jun;25(6):580-5
references.pmid: 15883982
references.citation: AJR Am J Roentgenol. 2000 Jan;174(1):81-8
references.pmid: 10628459
references.citation: Radiographics. 2002 Jul-Aug;22(4):817-32
references.pmid: 12110712
references.citation: Radiology. 1998 Mar;206(3):641-6
references.pmid: 9494480
references.citation: AJR Am J Roentgenol. 1999 Feb;172(2):439-44
references.pmid: 9930799
references.citation: Gastrointest Radiol. 1984;9(3):253-61
references.pmid: 6468863
references.citation: Urology. 1999 Sep;54(3):454-7
references.pmid: 10475353
references.citation: Int J Colorectal Dis. 1998;13(3):124-30
references.pmid: 9689562
references.citation: Am J Obstet Gynecol. 1999 Apr;180(4):815-23
references.pmid: 10203649
references.citation: Radiology. 2001 Mar;218(3):621-41
references.pmid: 11230632
references.citation: Abdom Imaging. 2005 Mar-Apr;30(2):195-203
references.pmid: 15719209
references.citation: Dis Colon Rectum. 2000 Oct;43(10):1419-26
references.pmid: 11052520
references.citation: Dis Colon Rectum. 1996 Jun;39(6):681-5
references.pmid: 8646957
references.citation: Colorectal Dis. 2008 Jan;10(1):84-8
references.pmid: 17441968
references.citation: AJR Am J Roentgenol. 1997 Sep;169(3):775-9
references.pmid: 9275895
references.citation: Dis Colon Rectum. 1996 Nov;39(11):1296-302
references.pmid: 8918443
references.citation: Gastroenterology. 2006 Apr;130(5):1480-91
references.pmid: 16678561