title: T2* mapping at 3.0T MRI for differentiation of papillary thyroid carcinoma from benign thyroid nodules.
abstract: OBJECTIVE
  To study the quantitative T2* mapping for thyroid nodules and to explore the use of T2* values to differentiate papillary thyroid carcinoma (PTC) from benign thyroid nodules, with histopathological examination as a reference standard.
  
  
  METHODS
  Twenty-eight consecutive patients with thyroid nodules were subjected to a 3.0T magnetic resonance imaging (MRI) examination. T2 * mapping was acquired using six echo times with a multiecho fast field echo (mFFE) sequence and constructed by exponentially fitting the multiecho T2* images pixel-by-pixel. The quality of the native T2* image was evaluated. An independent sample t-test was used to evaluate the statistical difference of the mean T2* value and the mean ratio of lesion to contralateral normal tissue between PTC and benign thyroid nodules. A receiver operating characteristic (ROC) curve was used to calculate the sensitivity and specificity.
  
  
  RESULTS
  The T2* value (mean: 21.73 ± 2.09 msec) and the ratio (mean: 1.61 ± 0.11) of PTC group were both significantly lower (P < 0.001) than those of the benign group (mean T2* value: 28.78 ± 5.02 msec, mean ratio: 2.18 ± 0.43). Applying a threshold value of 25.00 msec for T2* values and 1.795 for the ratio of lesion regions to normal tissue regions to identify PTC yielded a sensitivity of 84.2% and 89.5%, respectively, and a specificity of 100% for both.
  
  
  CONCLUSIONS
  T2* mapping can potentially provide quantitative information to separate PTC from benign thyroid nodules.
authors.affiliation: Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Ruoyang
authors.initials: R
authors.lastname: Shi
authors.affiliation: Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Qiuying
authors.initials: Q
authors.lastname: Yao
authors.affiliation: Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Lianming
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Head and Neck Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Qinyi
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Department of Pathology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Runlin
authors.initials: R
authors.lastname: Gao
authors.affiliation: Department of Radiology, Wayne State University, Detroit, Michigan, USA.
authors.forename: Jiani
authors.initials: J
authors.lastname: Hu
authors.affiliation: Department of Radiology, Wayne State University, Detroit, Michigan, USA.
authors.forename: Leslie
authors.initials: L
authors.lastname: Kao
authors.affiliation: Department of Radiology, Wayne State University, Detroit, Michigan, USA.
authors.forename: Ashika
authors.initials: A
authors.lastname: Bains
authors.affiliation: Department of Pathology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Zhaowen
authors.initials: Z
authors.lastname: Yan
authors.affiliation: Philips Healthcare, MR, China.
authors.forename: Yongming
authors.initials: Y
authors.lastname: Dai
authors.affiliation: Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging*; D002291:Carcinoma, Papillary; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging*; D016606:Thyroid Nodule / Q000000981:diagnostic imaging*
keywords: T2* mapping; T2* value; papillary thyroid carcinoma