title: US not bright but right method of thyroid volume estimation even in large and substernal extended goitres. Comparison of US and three methods of CT thyroid evaluation – prospective study.
abstract: BACKGROUND
  Ultrasound is nowadays a method of choice for thyroid volume assessment. However, its disadvantage is some inaccuracy, which is said to be higher in huge, especially substernally extended goitres.
  
  
  OBJECTIVE
  The aim of the study was to compare the US and CT thyroid volumetric measurements: multi-observers (CT MO) and one-observer (CT OO) to CT planimetry results (CT Pl) in patients with large goitres.
  
  
  METHODS
  The study material comprised 70 thyroid imaging examinations obtained from 35 patients with nontoxic goitres, scanned twice before and after radioiodine treatment. Mean thyroid volume was 88·97 ± 60·21 ml. Thirty-three thyroid scans revealed the extension below the jugular notch (mean of 2·46 cm). Thyroid volume in US, CT MO and CT OO was estimated using the ellipsoid formula. CT Pl was established a reference method.
  
  
  RESULTS
  The mean thyroid volume in CT Pl was 88·97 ml (median 80·73, range 11·81 to 315·97). US underestimates thyroid volume by 7·55 ml (7·7%) with a sufficient correlation (R(2) = 0·89) and precision (20·37). CT OO is the closest and CT MO the most distant from CT Pl, with US between them in thyroid volume estimation. The percentage US bias is constant through all range of thyroid volume. There is no difference for percentage bias between US and CT Pl for goitres with (8·67%), and without (6·70%) substernal part.
  
  
  CONCLUSIONS
  US examination is sufficient for epidemiological studies, radioiodine activity calculation and goitre size assessment in everyday medical practice. Neither initial size of the goitre nor its substernal extension affects US assessment precision.
authors.affiliation: Department of Endocrinology and Internal Medicine, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Sonia
authors.initials: S
authors.lastname: Kaniuka-Jakubowska
authors.affiliation: Department of Radiology, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Piskunowicz
authors.affiliation: Department of Radiology, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Zapaśnik
authors.affiliation: Department of Endocrinology and Internal Medicine, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Lewczuk
authors.affiliation: Department of Diagnostic Imaging and Interventional Radiology, Pomeranian Medical University, Szczecin, Poland.
authors.forename: Aneta
authors.initials: A
authors.lastname: Kaniuka
authors.affiliation: Department of Nuclear Medicine, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Mizan-Gross
authors.affiliation: Department of Economic Sciences, Faculty of Management and Economics, Gdansk University of Technology, Gdansk, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Kaszubowski
authors.affiliation: Department of Nuclear Medicine, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Lass
authors.affiliation: Department of Endocrinology and Internal Medicine, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Sworczak
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006045:Goiter, Substernal / Q000175:diagnosis / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D009929:Organ Size; D011446:Prospective Studies; D011859:Radiography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography