title: Utility of diffusion-weighted imaging in differentiating malignant from benign thyroid nodules with magnetic resonance imaging and pathologic correlation.
abstract: OBJECTIVE
  The objective of this study was to evaluate the role of magnetic resonance diffusion-weighted imaging (DWI) in differentiating malignant from benign thyroid nodules.
  
  
  METHODS
  The prospective study included 111 consecutive patients with solitary thyroid nodules (23 malignant and 88 benign nodules) who underwent DWI. The DWI signal and apparent diffusion coefficient (ADC) values of the nodules were determined and correlated with the histopathologic findings.
  
  
  RESULTS
  The majority (65%) of malignant thyroid nodules showed slightly hyperintense, and the majority (69%) of benign nodules were hyperintense on DWI (P < 0.01). The ADC values were lower in the thyroid cancer than in the adenoma and nodular goiter (P < 0.05). When the b factor was 500 s/mm, an ADC value of 1.704 × 10 mm/s can be threshold differentiating malignant from benign nodules, with 92% sensitivity, 88% specificity, and 87% accuracy. The higher cell density and more severe desmoplastic response were the causes of the lower ADC value of thyroid cancer.
  
  
  CONCLUSIONS
  Diffusion-weighted imaging can be a promising noninvasive imaging to discriminate malignant from benign nodules.
authors.affiliation: Department of Radiology, Jinshan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Hai Feng
authors.initials: HF
authors.lastname: Shi
authors.forename: Qin
authors.initials: Q
authors.lastname: Feng
authors.forename: Jin Wei
authors.initials: JW
authors.lastname: Qiang
authors.forename: Ruo Kun
authors.initials: RK
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Jian Ping
authors.initials: JP
authors.lastname: Yu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016606:Thyroid Nodule / Q000473:pathology*; D055815:Young Adult