title: Methylcellulose gel is a superior contrast agent for ultrasound examination of the cervix in obstetric patients.
abstract: OBJECTIVE
  To determine the superior contrast agent for cervical sonography: water-soluble methylcellulose gel vs. normal saline.
  
  
  METHODS
  Women with an indication for cervical sonography underwent placement of 10 mL water-soluble methylcellulose gel or normal saline. Assessment of cervical dimensions and contour was performed via transperineal sonography prior to and after contrast placement.
  
  
  RESULTS
  Twenty-five patients with similar demographic characteristics and indications for ultrasonography were enrolled into each group. Administration of contrast improved the ability to visualize the external os or vaginal fornices in 18 women in the gel group vs. six in the saline group (P = 0.002). In the gel group, 17 patients had easier identification of the external os and visualization of the fornices was enhanced in 13 patients. The assessment of cervical length prior to and after contrast administration was not statistically different with the use of either of these agents.
  
  
  CONCLUSIONS
  Intravaginal soluble gel is superior to normal saline as a cervical contrast agent. Intravaginal contrast may allow for easier identification of cervical anatomy during ultrasonographic examination in selected patients.
authors.affiliation: Department of Maternal-Fetal Medicine, Central Baptist Hospital, Lexington, KY 40503, USA. jobrien@bhsi.com
authors.forename: J M
authors.initials: JM
authors.lastname: O'Brien
authors.forename: B A
authors.initials: BA
authors.lastname: Houseman
authors.forename: A A
authors.initials: AA
authors.lastname: Allen
authors.forename: J R
authors.initials: JR
authors.lastname: Barton
mesh_terms: D000328:Adult; D002584:Cervix Uteri / Q000000981:diagnostic imaging; D003287:Contrast Media / Q000592:standards*; D005260:Female; D006801:Humans; D008747:Methylcellulose; D007752:Obstetric Labor, Premature / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D018566:Pregnancy, High-Risk; D011272:Pregnancy, Multiple; D016216:Ultrasonography, Prenatal / Q000379:methods* / Q000592:standards; D002581:Uterine Cervical Incompetence / Q000000981:diagnostic imaging*
chemical_list: D003287:Contrast Media; D008747:Methylcellulose