title: Sonographic patterns of benign thyroid nodules: verification at our institution.
abstract: OBJECTIVE
  The objective of our study was to apply the sonographic criteria for the diagnosis of benign thyroid nodules described by Bonavita et al. to our patient referral population.
  
  
  METHODS
  We performed a retrospective review of the sonographic features of 811 thyroid nodules that had undergone fine-needle aspiration biopsy in our radiology department from July 2005 to July 2009 and that had conclusive cytologic results. We determined the percentage of nodules that exhibited strictly the four benign sonographic patterns described by Bonavita et al. and the accuracy of those patterns in the prediction of benign cytologic findings.
  
  
  RESULTS
  Sixty-six nodules (8.1%) showed a spongiform pattern and all were benign; 28 nodules (3.5%) showed the pattern described as "cyst with colloid clot" and all were benign; 14 nodules (1.7%) showed a "giraffe" pattern and all were proven to be Hashimoto thyroiditis; and eight nodules (1%) showed the "white knight" pattern and all were Hashimoto thyroiditis. Of the 121 nodules in our series with malignant cytologic features, none exhibited any of these four benign patterns.
  
  
  CONCLUSIONS
  The four sonographic patterns described by Bonavita et al., when applied strictly, were 100% specific for benignity. However in our referral population, the application of these patterns would have eliminated the need for only 14% of biopsies, in contrast with 61% of biopsies in the population studied by Bonavita et al.
authors.affiliation: Department of Diagnostic Imaging, The Ottawa Hospital, University of Ottawa, 501 Smyth Rd, Ottawa, ON K1H8L6, Canada. drvivekvirmani@rediffmail.com
authors.forename: Vivek
authors.initials: V
authors.lastname: Virmani
authors.forename: Ian
authors.initials: I
authors.lastname: Hammond
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography