title: The diagnostic values of ultrasound and ultrasound-guided fine needle aspiration in subcentimeter-sized thyroid nodules.
abstract: BACKGROUND
  The diagnostic performances of ultrasound (US) examination and US-guided fine needle aspiration (US-FNA) were investigated in thyroid nodules ≤10 mm in size.
  
  
  METHODS
  From April 2006 to December 2006, 1440 nodules ≤10 mm in size in 1403 patients (mean age, 49.3 years; range, 10-84 years) underwent US and US-FNA. The association between nodule size and inadequate specimen was investigated using the Cochran-Armitage trend test and multivariate logistic regression analysis. To evaluate the diagnostic performances of US and US-FNA, we selected 852 nodules that had undergone surgery, follow-up US-FNA, or follow-up US. A receiver operating characteristic (ROC) curve analysis was used to determine the accuracies of US and US-FNA.
  
  
  RESULTS
  Of 1440 nodules, 256 (17.8%) yielded inadequate specimens. As the nodule size increased, the rate of inadequate specimens decreased (P < 0.001). A size of 6 mm demonstrated statistical significance between inadequate and adequate specimens (P < 0.001). The diagnostic accuracy of US was slightly improved as nodule size increased. The false positive rate of US examination was higher in nodules ≤6 mm compared with that of nodules >6 mm in size (P = 0.049). However, US-FNA demonstrated high diagnostic performance in all nodules with adequate specimen.
  
  
  CONCLUSIONS
  The inadequate specimens of US-FNA and false positives for US examinations increased as nodule size decreased. However, US-FNA demonstrated good diagnostic accuracy, assuming the specimen was adequate.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Moon
authors.forename: Eunju
authors.initials: E
authors.lastname: Son
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Yoon
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Kwak
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D002291:Carcinoma, Papillary / Q000175:diagnosis* / Q000601:surgery; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000601:surgery; D016606:Thyroid Nodule / Q000175:diagnosis* / Q000601:surgery; D013965:Thyroidectomy; D014465:Ultrasonics; D055815:Young Adult