title: Three-dimensional ultrasonographic assessment of fetal hands and feet.
abstract: OBJECTIVE
  The aim of this study was to describe fetal hands and feet using three-dimensional ultrasonography.
  
  
  METHODS
  This was a randomized prospective study.
  
  
  METHODS
  Ninety-seven fetuses from 12 to 40 weeks' gestation were studied with a specially developed trans-abdominal three-dimensional transducer (3.5 MHz). The imaging system used in this study can provide conventional two-dimensional ultrasound images and can also generate, within seconds, high-quality three-dimensional images in the surface and transparent modes with no need for an external workstation. The rate of visualization of the hands/fingers and feet/toes at each gestational-age interval was calculated using two-dimensional and three-dimensional ultrasonography.
  
  
  RESULTS
  The ability to visualize fetal hands/fingers and feet/toes was better with three-dimensional than with two-dimensional ultrasonography in the late first trimester (detection rates were 65% and 41% by three-dimensional ultrasonography for hands and feet, respectively, and 41% and 12%, respectively, by two-dimensional ultrasonography). For the early second trimester, detection rates were 82% for hands and 72% for feet by three-dimensional ultrasonography, and 54% for hands and 45% for feet by two-dimensional ultrasonography. Optimal visualization of the fetal fingers using three-dimensional ultrasonography was achieved between 28 and 35 weeks of gestation, although at this stage there were no significant differences in detection rates for hands and feet between two- and three-dimensional imaging. During this period it was possible with three-dimensional ultrasonography adequately to depict at least one hand in 93% of the fetuses at 28-31 weeks and in 88% at 32-35 weeks. The percentage of visualization of at least one fetal foot between 16 and 35 weeks using three-dimensional ultrasonography ranged from 50 to 85%. Before 15 weeks or after 36 weeks, the respective percentages decreased.
  
  
  CONCLUSIONS
  Three-dimensional ultrasonography provides a novel means of visualizing fetal fingers and toes. Our observations suggest that three-dimensional ultrasonography may enhance the diagnostic potential of two-dimensional ultrasonography and might be useful in identifying fetal malformations and anatomical markers of chromosomal abnormalities prenatally in high-risk pregnancies.
authors.affiliation: Department of Perinatology, Kagawa Medical University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hata
authors.forename: S
authors.initials: S
authors.lastname: Aoki
authors.forename: M
authors.initials: M
authors.lastname: Akiyama
authors.forename: T
authors.initials: T
authors.lastname: Yanagihara
authors.forename: K
authors.initials: K
authors.lastname: Miyazaki
mesh_terms: D005314:Embryonic and Fetal Development; D005260:Female; D005528:Foot / Q000196:embryology*; D005532:Foot Deformities, Congenital / Q000000981:diagnostic imaging*; D006225:Hand / Q000196:embryology*; D006228:Hand Deformities, Congenital / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D011247:Pregnancy; D011446:Prospective Studies; D011897:Random Allocation; D016216:Ultrasonography, Prenatal / Q000379:methods*