title: Ultrasonographic changes of the female bladder neck during development.
abstract: BACKGROUND
  Our previous study showed that the anteroposterior vesical wall angle (APVA) at the bladder neck on transabdominal ultrasonography varied widely between women. The present study examines whether the APVA changes during development in girls with a normal bladder.
  
  
  METHODS
  Seventy-four females aged 0-29 years with normal bladders were examined by transabdominal ultrasonography. They were divided into six age groups and their APVA was measured in the supine position by sagittal ultrasonography. Intravenous urography was conducted to examine bladder neck descent and bladder neck opening.
  
  
  RESULTS
  The APVA ranged from 85 to 200 degrees. The mean APVA in girls aged 0-4 years was 129 +/- 30 degrees (+/-SD) and the mean APVA in girls aged 5-9 years was 135 +/- 25 degrees. The mean APVA at ages 10-14 years was 161 +/- 26 degrees; at 15-19 years, 164 +/- 33 degrees; at 20-24 years, 164 +/- 18 degrees; and at 25-29 years, 163 +/- 16 degrees. The APVA values of these four groups were significantly larger (P < 0.05) than those of the two younger groups. No bladder abnormalities were found on intravenous urography.
  
  
  CONCLUSIONS
  The APVA was small in some girls under 10 years of age, but the APVA of girls aged over 10 years was similar to that in young adults. The APVA may reflect bladder base plate tone and be partially related to hormonal changes in females during development.
authors.affiliation: Department of Urology, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan. sugaya@med.u-ryuku.ac.jp
authors.forename: Kimio
authors.initials: K
authors.lastname: Sugaya
authors.forename: Saori
authors.initials: S
authors.lastname: Nishijima
authors.forename: Masami
authors.initials: M
authors.lastname: Oda
authors.forename: Tomoko
authors.initials: T
authors.lastname: Owan
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Ashitomi
authors.forename: Minoru
authors.initials: M
authors.lastname: Miyazato
authors.forename: Makoto
authors.initials: M
authors.lastname: Morozumi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hatano
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Ogawa
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D014463:Ultrasonography; D001743:Urinary Bladder / Q000000981:diagnostic imaging* / Q000254:growth & development*