title: Qualitative ultrasound elastography assessment of benign thyroid nodules: Patterns and intra-observer acquisition variability.
abstract: OBJECTIVE
  To report and evaluate qualitative elastography patterns by using gray-scale and Doppler ultrasound (US) in patients presenting with benign thyroid nodules and to evaluate the reproducibility of US elastography examinations.
  
  
  METHODS
  Institutional review board approval was obtained, and all patients provided informed consent. Over a 3-month time period, all consecutive adult patients were referred to our institution to undergo a thyroid nodule fine-needle aspiration biopsy (FNAB) procedure. Patients presenting with benign cytology according to the Bethesda 2008 classification were prospectively enrolled in the study. Each thyroid nodule was assessed by using gray-scale, Doppler US, and elastography acquisitions by a single operator (A. L.). Multiple elastography acquisitions per thyroid nodule were performed and elastography scorings of the nodules were compared with each other.
  
  
  RESULTS
  Nineteen patients (16 women and 3 men, mean age 58 years) with 22 thyroid nodules were included in the present study. Elastographic patterns 1, 2, and 3 were reported (23% nodules showed pattern 3). The elastography pattern showed a strong variability in 13 nodules (59%). The elastography acquisition result variability involved the "malignant" pattern 3 in 36% of cases.
  
  
  CONCLUSIONS
  Almost one-third of benign thyroid nodules displayed pattern 3 on qualitative US elastography. The intra-observer variability of the benign thyroid elastography scoring is wide, thus limiting the thyroid nodule US examination accuracy. In FNAB-proven benign thyroid nodules, elastography pattern 3 is frequent and cannot be used as a strong indicator of thyroid malignancy.
authors.affiliation: Centre d'imagerie Médicale, 47 Boulevard du Pont Rouge, 15000 Aurillac, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Lacout
authors.affiliation: Centre de Pathologie, 23 av République, 15000 Aurillac, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Chevenet
authors.affiliation: Department of Radiation Oncology, Antoine Lacassagne Cancer Research Center, 33 Avenue Valombrose, 06189 NICE cedex 1, France.
authors.forename: Juliette
authors.initials: J
authors.lastname: Thariat
authors.affiliation: Department Oncology Breast Surgery, Antoine Lacassagne Cancer Research Center, 33 Avenue Valombrose, 06189 NICE cedex 1, France.
authors.forename: Andrea
authors.initials: A
authors.lastname: Figl
authors.affiliation: Department of Medical Imaging, François Baclesse Center, 3, Avenue du Général Harris, 14076 Caen cedex 05, France.
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Marcy
keywords: Elastography; pattern; thyroid; variability