title: Three-dimensional versus two-dimensional ultrasound for assessing levonorgestrel intrauterine device location: A pilot study.
abstract: OBJECTIVE
  To compare the rates of success of two-dimensional (2D) and three-dimensional (3D) sonographic (US) examinations in locating and adequately visualizing levonorgestrel intrauterine devices (IUDs) and to explore factors associated with the unsuccessful viewing on 2D US.
  
  
  METHODS
  Transvaginal 2D and 3D US examinations were performed on all patients 1 month after insertion of levonorgestrel IUDs. The devices were considered adequately visualized on 2D US if both the vertical (shadow, upper and lower extremities) and the horizontal (two echogenic lines) shafts were identified. 3D volumes were also captured to assess the location of levonorgestrel IUDs on 3D US.
  
  
  RESULTS
  Thirty women were included. The rates of adequate device visualization were 40% on 2D US (95% confidence interval [CI], 24.6; 57.7) and 100% on 3D US (95% CI, 88.6; 100.0). The device was not adequately visualized in all six women who had a retroflexed uterus, but it was adequately visualized in 12 of the 24 women (50%) who had a nonretroflexed uterus (95% CI, -68.6; -6.8).
  
  
  CONCLUSIONS
  We found that 3D US is better than 2D US for locating and adequately visualizing levonorgestrel IUDs. Other well-designed studies with adequate power should be conducted to confirm this finding.
authors.affiliation: Family Planning Clinic, Department of Obstetrics, Paulista School of Medicine-São Paulo Federal University, (EPM-UNIFESP), Rua Napoleão de Barros, 875, Vila Clementino, CEP 04024-002, São Paulo-SP, Brazil.
authors.forename: Carla Maria Araujo
authors.initials: CM
authors.lastname: Andrade
authors.affiliation: Family Planning Clinic, Department of Obstetrics, Paulista School of Medicine-São Paulo Federal University, (EPM-UNIFESP), Rua Napoleão de Barros, 875, Vila Clementino, CEP 04024-002, São Paulo-SP, Brazil.
authors.forename: Edward
authors.initials: E
authors.lastname: Araujo Júnior
authors.affiliation: Family Planning Clinic, Department of Obstetrics, Paulista School of Medicine-São Paulo Federal University, (EPM-UNIFESP), Rua Napoleão de Barros, 875, Vila Clementino, CEP 04024-002, São Paulo-SP, Brazil.
authors.forename: Maria Regina
authors.initials: MR
authors.lastname: Torloni
authors.affiliation: Family Planning Clinic, Department of Obstetrics, Paulista School of Medicine-São Paulo Federal University, (EPM-UNIFESP), Rua Napoleão de Barros, 875, Vila Clementino, CEP 04024-002, São Paulo-SP, Brazil.
authors.forename: Antonio Fernandes
authors.initials: AF
authors.lastname: Moron
authors.affiliation: Family Planning Clinic, Department of Obstetrics, Paulista School of Medicine-São Paulo Federal University, (EPM-UNIFESP), Rua Napoleão de Barros, 875, Vila Clementino, CEP 04024-002, São Paulo-SP, Brazil.
authors.forename: Cristina Aparecida Falbo
authors.initials: CA
authors.lastname: Guazzelli
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007434:Intrauterine Devices; D016912:Levonorgestrel; D010865:Pilot Projects; D011446:Prospective Studies; D014463:Ultrasonography / Q000592:standards; D014599:Uterus / Q000000981:diagnostic imaging*
chemical_list: D016912:Levonorgestrel
keywords: gynecology; levonorgestrel; medicated intrauterine device; three-dimensional ultrasonography; two-dimensional ultrasonography