title: Diagnostic accuracy of ultrasound features in thyroid microcarcinomas.
abstract: OBJECTIVE
  To establish the usefulness of specific ultrasound (US) features as indications for ultrasound-guided fine needle aspiration biopsy (FNAB) in incidentally found infracentimetric thyroid nodules.
  
  
  METHODS
  The ultrasonographic features and cytology of FNAB samples of 96 histopathologically-proven papillary microcarcinomas (less than 1 cm in long diameter) and 75 less than 1 cm sized benign nodules were analyzed and compared. The risk of malignancy indicated by each US feature was calculated by logistic regression analysis.
  
  
  RESULTS
  Among the US features examined, internal content, shape, margin, echogenicity, and calcifications showed statistically significant differences between benign and malignant infracentimetric nodules. Crude odds ratios (OR) and 95% confidence intervals (CI) for risk of malignancy were, for solid content, OR = 39.3 (95% CI = 3.3-4.64); for taller than wide shape, OR = 14.2 (95% CI = 1.43-14.1); for hypoechogenicity, OR = 3.57 (95% CI = 1.31-9.86); for marked hypoechogenicity, OR = 31.33 (95% CI = 6.63-14.8); and for coarse macrocalcifications, OR = 3.43 (95% CI = 1.04-11.3).
  
  
  CONCLUSIONS
  Infracentimetric nodules that are solid, taller than wide, hypoechogenic or markedly hypoechogenic, and have coarse microcalcifications and macrocalcifications have a high risk of malignancy, indicating further assessment.
authors.affiliation: Department of Radiology, Seoul National University Bundang Hospital, Korea.
authors.forename: Yoon Jung
authors.initials: YJ
authors.lastname: Choi
authors.forename: Sun Mi
authors.initials: SM
authors.lastname: Kim
authors.forename: Sang Il
authors.initials: SI
authors.lastname: Choi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D002114:Calcinosis / Q000000981:diagnostic imaging; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011379:Prognosis; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D014463:Ultrasonography