Validation of volume measurements in esophageal pseudotumors using 3D endoluminal ultrasound

The purpose of this study was to validate the accuracy and reliability of v olume measurements using three-dimensional (3D) endoluminal ultrasound (ELU S) in canine pseudotumor esophageal specimens in vitro, Pseudotumors were c reated by injecting various volumes of US gel (0.1-1.0 ml) into canine esop hageal specimens. A stepping-motor was used to pull either a 9, 12.5 or 20 MHz transducer through the lumen of the specimen at 1.5 mm/s. Images were d ownloaded to a LIFE computer system for 3D reconstruction. Volume measureme nts mere made by two investigators and compared to spiral CT images. Averag ing across all measurements, the average magnitude of error was 8.7% in ind ividual US determinations and 11.9% in CT measures. Volumes estimated from images spaced 0.5 and 1.0 mm apart, from images in the original and reconst ructed planes, and from different scan frequencies, produced percentage err ors that mere not statistically significantly different from each other on ELUS, 3D ELUS can be used accurately and reproducibly to measure tumor volu mes with a low mean percent irt vitro, (C) 2000 World Federation for Ultras ound in Medicine & Biology.