title: Diffusion-weighted images differentiate benign from malignant thyroid nodules.
abstract: OBJECTIVE
  To reveal the possible role of diffusion-weighted images (DWI) in the differential diagnosis of benign and malignant thyroid nodules by comparing the results of fine-needle aspiration cytology (FNAC).
  
  
  METHODS
  In an 18-month period (December 2005 to May 2007), 27 cases with benign thyroid nodules with a total of 52 benign nodules, nine cases with thyroid gland malignancy, and 24 healthy control cases were included in the study. Cases that were indicated to undergo to FNAC examination and sent by a clinician for biopsy to the radiology unit were included in the study to assess the cytopathologic confirmation of the clinic, ultrasonographic, and magnetic resonance imaging (MRI) findings.
  
  
  RESULTS
  The mean apparent diffusion coefficient (ADC) values of thyroid nodules were 2745.3 +/- 601.1 x 10(-6) mm(2)/s (1605-3899 x 10(-6)mm(2)/s) in the benign group and 695.2 +/- 312.5 x 10(-6)mm(2)/s (165-1330 x 10(-6)mm(2)/s) in the malignant group. Normal thyroid tissues had mean ADC values of 1344.1 +/- 276.4 x 10(-6) mm(2)/s (1015-1764 x 10(-6)mm(2)/s). The ADC values of three subgroups were significantly different (P = 0.0001). A reduced ADC was observed in most types of malignant tumors due to the consequent decrease of the extracellular extravascular space.
  
  
  CONCLUSIONS
  Our preliminary results showed that ADC values of nodules may provide useful data about the nature of a thyroid nodule.
authors.affiliation: Inonu University, School of Medicine, Department of Radiology, Malatya, Turkey. gerdem@inonu.edu.tr
authors.forename: Gulnur
authors.initials: G
authors.lastname: Erdem
authors.forename: Tamer
authors.initials: T
authors.lastname: Erdem
authors.forename: Hakki
authors.initials: H
authors.lastname: Muammer
authors.forename: Deniz Yakar
authors.initials: DY
authors.lastname: Mutlu
authors.forename: Ahmet Kemal
authors.initials: AK
authors.lastname: Firat
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Sahin
authors.forename: Alpay
authors.initials: A
authors.lastname: Alkan
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity