title: Role of duplex power Doppler ultrasound in differentiation between malignant and benign thyroid nodules.
abstract: OBJECTIVE
  To evaluate the usage of duplex power Doppler ultrasound (PDUS) for the differentiation of benign and malignant thyroid nodules.
  
  
  METHODS
  We prospectively examined 77 thyroid nodules in 60 patients undergoing ultrasound-guided fine needle aspiration biopsy (FNAB). Each nodule was described according to size, inner structure, borders, parenchymal echogenicity, peripheral halo formation, and the presence of calcification (B-mode ultrasound findings). Vascularity as determined by PDUS imaging was defined as non-vascular, peripheral, central, or of mixed type. For each nodule, the pulsatility index (PI) and resistive index (RI) values were obtained. Results of FNAB and surgical pathological examination (if available) were used as a proof of final diagnosis to categorize all nodules as benign or malignant. A receiver operating characteristic (ROC) curve analysis was performed to establish cut-off, sensitivity, and specificity values associated with RI-PI values.
  
  
  RESULTS
  A significant relationship was observed between malignancy and irregular margins, microcalcifications, and hypoechogenicity on ultrasound examination (p < 0.05). The pattern of vascularity as determined by PDUS analysis was not a statistically significant criterion to suggest benign or malignant disease in this study (p > 0.05). The central, peripheral, and mean RI-PI values were higher in malignant nodules when compared to the other cytologies (p < 0.05).
  
  
  CONCLUSIONS
  Vascularity is not a useful parameter for distinguishing malignant from benign thyroid nodules. However, RI and PI values are useful in distinguishing malignant from benign thyroid nodules.
authors.affiliation: Department of Radiology, Ataturk Training and Research Hospital Bilkent, Ankara, Turkey. droktayalgin@gmail.com
authors.forename: Oktay
authors.initials: O
authors.lastname: Algin
authors.forename: Efnan
authors.initials: E
authors.lastname: Algin
authors.forename: Gokhan
authors.initials: G
authors.lastname: Gokalp
authors.forename: Gokhan
authors.initials: G
authors.lastname: Ocakoğlu
authors.forename: Cüneyt
authors.initials: C
authors.lastname: Erdoğan
authors.forename: Ozlem
authors.initials: O
authors.lastname: Saraydaroglu
authors.forename: Ercan
authors.initials: E
authors.lastname: Tuncel
mesh_terms: D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000473:pathology; D018616:Ultrasonography, Doppler, Duplex; D018084:Ultrasonography, Interventional