title: TIRADS for sonographic assessment of hypofunctioning and indifferent thyroid nodules.
abstract: OBJECTIVE
  To test the feasibility of the Thyroid Imaging Reporting And Data System (TIRADS) according to Horvath and Kwak for the assessment of thyroid nodules.
  
  
  METHODS
  Retrospective analysis of patients with thyroid nodules applying the following inclusion criteria: B-mode-ultrasound, surgery and histological results. Thyroid nodules were classified as TIRADS 2, 3, 4A, 4B, 4C, 5 and 6.
  
  
  RESULTS
  A total of 172 patients were included (133 women, 48 ± 13 years, 39 men, 49 ± 11 years) with 222 thyroid nodules (24.9 ± 11.5 mm). Final histological diagnosis revealed 203 benign nodules (91%) and 19 malignant nodules (9%; 18 papillary thyroid carcinoma, PTC, and one medullary thyroid carcinoma, MTC). One hundred and sixty thyroid nodules were hypofunctioning in 99mTc-pertechnetate-scintigraphy, 14 nodules were hyperfunctioning and 46 nodules were classified as indifferent. In two cases with small carcinoma < 1 cm 99mTc-pertechnetate-scintigraphy was not performed. According to Horvath, the prevalence of malignancy was 6.7% in TIRADS 2, 0% in 3, 1.9% in 4A, 33% in 4B, 12.5% in 5 and 100% in 6; 73 nodules (39%) were not clearly classifiable, including 3 carcinoma (4.1%). According to Kwak, the prevalence of malignancy was 6.9% in TIRADS 2, 0% in 3, 2% in 4A, 4.1% in 4B, 23.1% in 4C, and 100% in 5 and 6, respectively. Notably, in the subgroup of hot nodules, 11 (79%) were graded as TIRADS 4A or higher, and thus advisable for fine-needle aspiration biopsy in both TIRADS.
  
  
  CONCLUSIONS
  The TIRADS described by Horvath is not practicable due to numerous unclassifiable nodules. The revised TIRADS published by Kwak is feasible and suitable to assess the prevalence of malignancy, but it cannot replace scintigraphic imaging. Fine-needle-biopsy is not necessary in nodules categorized as (K)TIRADS 3, 4A and 5.
authors: Dr. med. Simone Schenke, ÜBAG für Nuklearmedizin Hanau, Leimenstr. 20, 63450 Hanau, E-mail: simoneschenke@web.de.
authors: Simone
authors: S
authors: Schenke
authors: T
authors: T
authors: Rink
authors: M
authors: M
authors: Zimny
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D015995:Prevalence; D011873:Radiology Information Systems / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000145:classification / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D016606:Thyroid Nodule / Q000145:classification / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D014463:Ultrasonography
keywords: TIRADS; thyroid carcinoma; thyroid nodules; ultrasound features