title: Segmentations of MRI images of the female pelvic floor: a study of inter- and intra-reader reliability.
abstract: OBJECTIVE
  To describe the inter- and intra-operator reliability of segmentations of female pelvic floor structures.
  
  
  METHODS
  Three segmentation specialists were asked to segment out the female pelvic structures in 20 MR datasets on three separate occasions. The STAPLE algorithm was used to compute inter- and intra-segmenter agreement of each organ in each dataset. STAPLE computed the sensitivity, specificity, and positive predictive values (PPV) for inter- and intra-segmenter repeatability. These parameters were analyzed using intra-class correlation analysis. Correlation of organ volume to PPV and sensitivity was also computed.
  
  
  RESULTS
  Mean PPV of the segmented organs ranged from 0.82 to 0.99, and sensitivity ranged from 33 to 96%. Intra-class correlation ranged from 0.07 to 0.98 across segmenters. Pearson correlation of volume to sensitivity were significant across organs, ranging from 0.54 to 0.91. Organs with significant correlation of PPV to volume were bladder (-0.69), levator ani (-0.68), and coccyx (-0.63).
  
  
  CONCLUSIONS
  Undirected manual segmentation of the pelvic floor organs are adequate for locating the organs, but poor at defining structural boundaries.
authors.affiliation: University of South Florida, College of Medicine, Division of Urogynecology and Pelvic Reconstructive Surgery, Tampa General Hospital, Urogynecology Division, Tampa, Florida, USA. lennox@mindspring.com
authors.forename: Lennox
authors.initials: L
authors.lastname: Hoyte
authors.forename: Wen
authors.initials: W
authors.lastname: Ye
authors.forename: Linda
authors.initials: L
authors.lastname: Brubaker
authors.forename: Julia R
authors.initials: JR
authors.lastname: Fielding
authors.forename: Mark E
authors.initials: ME
authors.lastname: Lockhart
authors.forename: Marta E
authors.initials: ME
authors.lastname: Heilbrun
authors.forename: Morton B
authors.initials: MB
authors.lastname: Brown
authors.forename: Simon K
authors.initials: SK
authors.lastname: Warfield
mesh_terms: D000465:Algorithms; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015588:Observer Variation; D017773:Pelvic Floor / Q000473:pathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity