title: MRI of sonographically indeterminate adnexal masses.
abstract: OBJECTIVE
  The purpose of this study was to assess the ability of MRI to characterize sonographically indeterminate adnexal masses and to define the sonographic features contributing to indeterminate diagnoses.
  
  
  METHODS
  Two blinded radiologists retrospectively reviewed the MRI examinations of 87 patients with 95 sonographically indeterminate adnexal masses. Reviewers determined the origin of a mass, its tissue content (cystic, solid, complex cystic, or cystic and solid), tissue characteristics (fat, blood, fibrous, or leiomyomatous), and benignity versus malignancy. Sonograms were reviewed by three reviewers to determine the origin of a mass, its tissue content, and reasons for an indeterminate diagnosis. Sensitivity and specificity of MRI were calculated, and agreement of sonography and MRI with the final diagnosis was determined using kappa statistics. The final diagnosis was determined by histopathology, surgical findings, or imaging or clinical follow-up.
  
  
  RESULTS
  The sensitivity of MRI for identifying malignancy (n = 5) was 100% and its specificity for benignity (n = 90) was 94%. Excellent agreement was seen between MRI and the final diagnosis for determining the origin (kappa = 0.93), tissue content (kappa = 0.98), and tissue characteristics (kappa = 0.91) of a mass. Sonography had poor agreement with the final diagnosis for the origin (kappa = 0.19) and tissue content (kappa = 0.33) of a mass. The main reasons for indeterminate sonographic diagnoses were the inability to determine origin because of location and large mass size and the appearances of purely solid or complex cystic masses.
  
  
  CONCLUSIONS
  Sonographically indeterminate adnexal masses of uncertain origin and solid or complex cystic content benefit from further evaluation with MRI, which is highly accurate for identifying the origin of a mass and characterizing its tissue content, obviating surgery.
authors.affiliation: Department of Radiology, University of Michigan Health System, UH B2 A-209-R, 1500 E Medical Center Dr, Ann Arbor, MI 48109-0030, USA. saroja@umich.edu
authors.forename: Saroja
authors.initials: S
authors.lastname: Adusumilli
authors.forename: Hero K
authors.initials: HK
authors.lastname: Hussain
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Caoili
authors.forename: William J
authors.initials: WJ
authors.lastname: Weadock
authors.forename: John P
authors.initials: JP
authors.lastname: Murray
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Johnson
authors.forename: Qixuan
authors.initials: Q
authors.lastname: Chen
authors.forename: Benoit
authors.initials: B
authors.lastname: Desjardins
mesh_terms: D000290:Adnexa Uteri / Q000473:pathology*; D000291:Adnexal Diseases / Q000175:diagnosis*; D000293:Adolescent; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005833:Genital Neoplasms, Female / Q000175:diagnosis; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015588:Observer Variation; D012189:Retrospective Studies; D012680:Sensitivity and Specificity