title: Factors affecting inadequate sampling of ultrasound-guided fine-needle aspiration biopsy of thyroid nodules.
abstract: OBJECTIVE
  The aim of this study was to evaluate the overall ultrasonographic features and clinical factors that contribute to inadequate sampling in ultrasound-guided fine-needle aspiration biopsy (US-FNAB) of thyroid nodules.
  
  
  METHODS
  From April 2008 to December 2008, 4077 US-FNABs in 3767 consecutive patients were reviewed. We evaluated the clinical, ultrasound and pathological features of patients and analysed the association between these features and inadequate samples. We also compared inadequate sample rates according to the experience of the performing doctor.
  
  
  RESULTS
  The inadequate sample rate was 16·1% (654/4077). Univariate analysis revealed an association between inadequate samples and cyst dominancy, macrocalcification and benign pathology of the nodule. The inadequate sample rate was also higher in the inexperienced group than in the experienced group. In multivariate analysis, cyst dominancy and macrocalcification of a nodule were significantly associated with inadequate samples in the experienced group.
  
  
  CONCLUSIONS
  Cyst dominancy and macrocalcifications in thyroid nodules, inexperience of the performing doctor and benign pathology were factors associated with high inadequate sample rates of US-FNAB in thyroid nodules.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seon Hyeong
authors.initials: SH
authors.lastname: Choi
authors.forename: Kyung Hwa
authors.initials: KH
authors.lastname: Han
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Yoon
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Moon
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Son
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Youk
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Kwak
mesh_terms: D000328:Adult; D044963:Biopsy, Fine-Needle / Q000379:methods* / Q000592:standards; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000473:pathology; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography / Q000379:methods*