title: Evaluation of gallbladder volume and emptying with a novel three-dimensional ultrasound system: comparison with the sum-of-cylinders and the ellipsoid methods.
abstract: To overcome the geometrical limitations of current methods to calculate gallbladder volume from two-dimensional sonographic images, we evaluated the accuracy and precision of a novel three-dimensional ultrasound system (3D). In vitro accuracy of 3D volumetry (10 mL to 55 mL) was 98.1 +/- 7.1% (mean+/-SD) with a mean difference of 0.7 mL between the measured and the true volume (p < 0.003). Compared with the sum-of-cylinders (SC) and the ellipsoid (EL) methods, 3D was characterized by a significantly smaller systematic bias and closer limits of agreement with the true volume. The variation coefficient was smallest with 3D (2.4%, p < 0.02) and largest with EL (4.2%). In vivo, gallbladder volumes were on average 1.4 mL (9%) smaller with 3D than with SC (p < 0.0001) and 2.4 mL (14%) larger with EL than with SC (p < 0.0001). 3D ultrasonography accurately measures gallbladder volume and emptying.
authors.affiliation: Department of Medicine II, Klinikum Grosshadern, University of Munich, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Pauletzki
authors.forename: M
authors.initials: M
authors.lastname: Sackmann
authors.forename: J
authors.initials: J
authors.lastname: Holl
authors.forename: G
authors.initials: G
authors.lastname: Paumgartner
mesh_terms: D002769:Cholelithiasis / Q000000981:diagnostic imaging; D005260:Female; D005704:Gallbladder / Q000000981:diagnostic imaging*; D016473:Gallbladder Emptying / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation*