title: Thyroid volumetric quantification: comparative evaluation between conventional and volumetric ultrasonography.
abstract: OBJECTIVE
  Thyroid volume quantification is an important parameter for radiotherapy dosing in cases of major thyroid diseases such as thyroiditis and carcinoma. In clinical practice, this calculation is performed by means of ultrasonography on the basis of an ellipsoid formula obtained from the 3 axes. The aim of our study was to compare the accuracy of volume calculation between B-mode ultrasonography and volumetric ultrasonography (VUS).
  
  
  METHODS
  Between April and May 2007, 27 consecutive patients selected for thyroidectomy were prospectively evaluated. One expert ultrasound operator calculated each thyroid volume with standard B-mode ultrasonography on the basis of the 3 axes of each lobe, and then the patients were analyzed with an offline workstation equipped with volumetric probes (VUS). On the offline workstation, 2 separate blinded operators (VUS1 and VUS2) calculated the thyroid volume with virtual organ computer-aided analysis. Data acquired were then compared with pathologic anatomy (PA).
  
  
  RESULTS
  The mean time for B-mode analysis was 6 minutes, whereas VUS analysis needed a mean time of 16.5 minutes. Interobserver variability between the median VUS1 and VUS2 measurements was 0.36 mL (interquartile range [IQR], -0.79 to 0.37 mL; P < .156). The median variability between B-mode ultrasonography and PA was -9.6 mL (IQR, -16.7 to 1.5 mL; P < .001), and that between VUS and PA was -2.87 mL (IQR, -11.97 to 9.51 mL; P = .019). The overall performance of B-mode ultrasonography in comparison with PA was -29.1% (IQR, -47.5% to -5.9%), and that of VUS in comparison with PA was -6.3% (IQR, -26.3 to 13.7%; P < .001).
  
  
  CONCLUSIONS
  Volumetric ultrasonography is a valid tool that compares better with PA than does B-mode ultrasonography.
authors.affiliation: Department of Radiology, Policlinico G. B. Rossi, University of Verona, Verona, Italy. rmalag@sirm.org
authors.forename: Roberto
authors.initials: R
authors.lastname: Malago
authors.forename: Mirko
authors.initials: M
authors.lastname: D'Onofrio
authors.forename: Marco
authors.initials: M
authors.lastname: Ferdeghini
authors.forename: William
authors.initials: W
authors.lastname: Mantovani
authors.forename: Chiara
authors.initials: C
authors.lastname: Colato
authors.forename: Paolo
authors.initials: P
authors.lastname: Brazzarola
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Motton
authors.forename: Roberto Pozzi
authors.initials: RP
authors.lastname: Mucelli
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013959:Thyroid Diseases / Q000000981:diagnostic imaging*; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*