title: Assessing the accuracy and reliability of ultrasonographic three-dimensional parathyroid volume measurement in a patient with secondary hyperparathyroidism: a comparison with the two-dimensional conventional method.
abstract: OBJECTIVE
  The purpose of this study was to investigate the accuracy and reliability of the semi-automated ultrasonographic volume measurement tool, virtual organ computer-aided analysis (VOCAL), for measuring the volume of parathyroid glands.
  
  
  METHODS
  Volume measurements for 40 parathyroid glands were performed in patients with secondary hyperparathyroidism caused by chronic renal failure. The volume of the parathyroid glands was measured twice by experienced radiologists by two-dimensional (2D) and three-dimensional (3D) methods using conventional sonograms and the VOCAL with 30°angle increments before parathyroidectomy. The specimen volume was also measured postoperatively. Intraclass correlation coefficients (ICCs) and the absolute percentage error were used for estimating the reproducibility and accuracy of the two different methods.
  
  
  RESULTS
  The ICC value between two measurements of the 2D method and the 3D method was 0.956 and 0.999, respectively. The mean absolute percentage error of the 2D method and the 3D VOCAL technique was 29.56% and 5.78%, respectively. For accuracy and reliability, the plots of the 3D method showed a more compact distribution than those of the 2D method on the Bland-Altman graph.
  
  
  CONCLUSIONS
  The rotational VOCAL method for measuring the parathyroid gland is more accurate and reliable than the conventional 2D measurement. This VOCAL method could be used as a more reliable follow-up imaging modality in a patient with hyperparathyroidism.
authors.affiliation: Department of Radiology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Sung-Hye
authors.identifier: 0000-0001-5005-9383
authors.initials: SH
authors.lastname: You
authors.affiliation: Department of Radiology, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Sang-Il
authors.identifier: 0000-0001-8933-0492
authors.initials: SI
authors.lastname: Suh
authors.affiliation: Department of Radiology, Korea University Guro Hospital, Seoul, Korea.
authors.forename: In-Seon
authors.identifier: 0000-0001-6866-7926
authors.initials: IS
authors.lastname: Ryoo
authors.affiliation: Department of Radiology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Gyu-Ri
authors.identifier: 0000-0003-0614-071X
authors.initials: GR
authors.lastname: Son
authors.affiliation: Department of Radiology, Korea University Ansan Hospital, Ansan, Korea.
authors.forename: Young-Hen
authors.identifier: 0000-0001-7739-4173
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Radiology, Korea University Ansan Hospital, Ansan, Korea.
authors.forename: Hyung Suk
authors.identifier: 0000-0003-2303-7415
authors.initials: HS
authors.lastname: Seo
authors.affiliation: Department of Radiology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Nam Joon
authors.identifier: 0000-0002-4538-092X
authors.initials: NJ
authors.lastname: Lee
authors.affiliation: Department of Radiology, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Hae Young
authors.identifier: 0000-0003-4231-5409
authors.initials: HY
authors.lastname: Seol
keywords: Imaging, three-dimensional; Organ size; Parathyroid glands; Ultrasonography