title: Efficacy of thyroid ultrasound elastography in differential diagnosis of small thyroid nodules.
abstract: OBJECTIVE
  To explore the efficacy of thyroid ultrasound (US) elastography in differential diagnosis of small thyroid nodules.
  
  
  METHODS
  This HIPAA-compliant study was approved by the Institutional Review Board and all patients provided written informed consent. Thirty-five patients with 38 small thyroid nodules as seen on transverse ultrasound image formed our study population. An US examination and a separate thyroid elastography examination with pulsation from the carotid artery used as the compression source were performed before fine-needle aspiration. Baseband US data were acquired for off-line elastography processing, where a semi-quantitative index for each nodule was calculated. The Kruskal-Wallis nonparametric rank sum test was used to assess equality of population means among the different types of thyroid nodules. Maximum likelihood estimation of the curve parameters for a binomial receiver operating characteristic (ROC) curve was performed.
  
  
  RESULTS
  Elasticity contrast index calculated with elastography was effective in distinguishing between small papillary thyroid carcinomas (PTMC, n=8) and other lesions (n=30) in small thyroid nodules (p=0.0036). The area under the ROC curve for diagnosing PTMCs was 0.812 with a 95% confidence interval of 0.653-0.920. The cut-off value of ECI of 3.6 led to a sensitivity of 100% and a specificity of 60% for detecting PTMCs.
  
  
  CONCLUSIONS
  Noninvasive evaluation of small thyroid nodules is possible using thyroid US elastography with in vivo compression to pick out the most suspicious thyroid nodules for fine-needle aspiration (FNA) and avoid FNA in benign nodules.
authors: Department of Radiology, Box 357115, 1959 NE Pacific Street, University of Washington, Seattle, WA 98195, USA. dighe@u.washington.edu
authors: Manjiri
authors: M
authors: Dighe
authors: Si
authors: S
authors: Luo
authors: Carlos
authors: C
authors: Cuevas
authors: Yongmin
authors: Y
authors: Kim
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D014861:Washington / Q000453:epidemiology; D055815:Young Adult