title: New sonographic criteria for recommending fine-needle aspiration biopsy of nonpalpable solid nodules of the thyroid.
abstract: OBJECTIVE
  The purpose of our study was to provide new sonographic criteria for fine-needle aspiration biopsy of nonpalpable solid thyroid nodules.
  
  
  METHODS
  Sonographic scans of 155 nonpalpable thyroid nodules in 132 patients were prospectively classified as having positive or negative findings. Sonographic findings that suggested malignancy included microcalcifications, an irregular or microlobulated margin, marked hypoechogenicity, and a shape that was more tall than it was wide. If even one of these sonographic features was present, the nodule was classified as positive (malignant). If a nodule had none of the features described, it was classified as negative (benign). The final diagnosis of a lesion as benign (n = 106) or malignant (n = 49) was confirmed by fine-needle aspiration biopsy and follow-up (>6 months) in 83 benign nodules, by fine-needle aspiration biopsy and surgery in 44 malignant and 15 benign lesions, and by surgery alone in five malignant and eight benign lesions. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated on the basis of our proposed classification method.
  
  
  RESULTS
  Of 82 lesions classified as positive, 46 were malignant. Of 73 lesions classified as negative, three were malignant. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy based on our sonographic classification method were 93.8%, 66%, 56.1%, 95.9%, and 74.8%, respectively.
  
  
  CONCLUSIONS
  Considering the high level of sensitivity of our proposed sonographic classification, fine-needle aspiration biopsy should be performed on thyroid nodules classified as positive, regardless of palpability.
authors.affiliation: Department of Diagnostic Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 134, Shinchon-dong, Seodaemun-gu, Seoul 120-752, Korea.
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Cheong Soo
authors.initials: CS
authors.lastname: Park
authors.forename: Woung Youn
authors.initials: WY
authors.lastname: Chung
authors.forename: Ki Keun
authors.initials: KK
authors.lastname: Oh
authors.forename: Dong Ik
authors.initials: DI
authors.lastname: Kim
authors.forename: Jong Tae
authors.initials: JT
authors.lastname: Lee
authors.forename: Hyung Sik
authors.initials: HS
authors.lastname: Yoo
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D002114:Calcinosis / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D016606:Thyroid Nodule / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography