title: Three-dimensional esophageal varix model quantification of variceal volume by high-resolution endoluminal US.
abstract: BACKGROUND
  The purpose of this study was to evaluate the accuracy and reproducibility of three-dimensional volume measurements by high-resolution endoluminal ultrasound in an esophageal varix model.
  
  
  METHODS
  An esophageal varix model was made by filling three esophageal dilatation catheters with various volumes of water. A 20 MHz ultrasonography transducer was then pulled along the length of the catheters at a constant rate (1.25 mm/sec) while videotaping the procedure. Cross-sectional surface area measurements of each catheter were taken every second and the cross-sectional surface area was multiplied by the length of each catheter, as determined by high-resolution endoluminal ultrasound, to determine the volume in each catheter. Interobserver variability was calculated, and three-dimensional reconstruction was performed.
  
  
  RESULTS
  The measured volumes corresponded closely with the actual volumes with an error ranging from 0% to 15.4%. The correlation between actual and measured volumes was r = 0.988. The interobserver variability ranged from r = 0.951 to r = 0.994. Actual esophageal varices were then imaged in a similar fashion to determine the feasibility of this method in patients with esophageal varices.
  
  
  CONCLUSIONS
  High-resolution endoluminal ultrasound is an accurate and reproducible method of measuring volumes in an esophageal varix model and can be used in a clinical setting to determine variceal volume. Volume studies are now underway in human subjects.
authors.affiliation: Temple University Hospital, Department of Gastroenterology, Philadelphia, PA 19140, USA.
authors.forename: C Y
authors.initials: CY
authors.lastname: Chung
authors.forename: W H
authors.initials: WH
authors.lastname: McCray
authors.forename: S
authors.initials: S
authors.lastname: Dhaliwal
authors.forename: T
authors.initials: T
authors.lastname: Haywood
authors.forename: M
authors.initials: M
authors.lastname: Black
authors.forename: J B
authors.initials: JB
authors.lastname: Liu
authors.forename: L S
authors.initials: LS
authors.lastname: Miller
mesh_terms: D019160:Endosonography / Q000379:methods*; D004932:Esophageal and Gastric Varices / Q000175:diagnosis / Q000000981:diagnostic imaging*; D005069:Evaluation Studies as Topic; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity