title: Clinical trial of multiplanar real-time 4- versus 2-dimensional sonographic guidance for transcervical chorionic villus sampling.
abstract: OBJECTIVE
  Real-time 4-dimensional (4D) sonography can visualize the location of a chorionic villus sampling (CVS) catheter simultaneously in 3 dimensions. We determined the utility of 4D versus 2-dimensional (2D) sonographic guidance for transcervical CVS.
  
  
  METHODS
  Chorionic villus sampling was performed on 40 patients at 10 to 13 weeks' gestation (20 in each study group). Primary outcomes were as follows: (1) time in seconds needed to complete the procedure; (2) procedure failure, defined as the inability to obtain an adequate sample by a single catheter insertion or a necessity to switch to the alternative imaging modality; and (3) acquisition of a sample of chorionic villi sufficient for cytogenetic analysis. Wilcoxon rank sum and Fisher exact tests were used for categorical and continuous variables, respectively. Figure 1. A, Two-dimensional guidance of the transcervical chorionic villus sampling procedure. Arrows indicate the chorionic villus sampling catheter. B, Multiplanar 3-dimensional guidance of the procedure.
  
  
  RESULTS
  The procedure time was significantly longer in the 4D group than the 2D group (161.4 versus 80.4 seconds, respectively; P = .001). The success rate at first introduction of the catheter was higher for 2D guidance (90%) than 4D guidance (70%) but was not statistically significant with the study group sizes. Adequate sample sizes were obtained in all patients. The main limiting factor in 4D guidance was a low frame rate.
  
  
  CONCLUSIONS
  Our findings show the feasibility of 4D guidance for transcervical CVS, although at the expense of a prolonged procedure time when compared to 2D sonographic guidance. The value of 4D guidance for less experienced operators remains to be determined.
authors.affiliation: Maternal-Fetal Center, Children's Hospital of Central California, Madera, California, USA; Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, California, USA. benadeniji@gmail.com
authors.forename: Beni
authors.initials: B
authors.lastname: Adeniji
authors.forename: John
authors.initials: J
authors.lastname: Williams
authors.forename: Ido
authors.initials: I
authors.lastname: Solt
authors.forename: Carlos
authors.initials: C
authors.lastname: Morales
authors.forename: Artemis
authors.initials: A
authors.lastname: Alanakian
authors.forename: Siegfried
authors.initials: S
authors.lastname: Rotmensch
mesh_terms: D000328:Adult; D000465:Algorithms; D002824:Chorionic Villi / Q000000981:diagnostic imaging* / Q000473:pathology*; D015193:Chorionic Villi Sampling / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D061705:Image-Guided Biopsy / Q000379:methods*; D008875:Middle Aged; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018084:Ultrasonography, Interventional / Q000379:methods*; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055815:Young Adult