title: The diagnosis value of acoustic radiation force impulse (ARFI) elastography for thyroid malignancy without highly suspicious features on conventional ultrasound.
abstract: OBJECTIVE
  The aim of this study was to evaluate the potential diagnostic performance of acoustic radiation force impulse (ARFI) elastography in identifying malignancy in nodules that do not appear highly suspicious on conventional ultrasound (US).
  
  
  METHODS
  330 pathologically confirmed thyroid nodules (40 malignant and 290 benign; mean size, 22.0±11.6 mm) not suspicious of malignancy on conventional US in 330 patients (mean age 52.8±11.7 years) underwent ARFI elastography before surgery. ARFI elastography included qualitative ARFI-induced strain elastography (SE) and quantitative point shear wave elastography (p-SWE). ARFI-induced SE image was assessed by SE score, while p-SWE was denoted with shear wave velocity (SWV, m/s). The diagnostic performance of four criteria sets was evaluated: criteria set 1 (ARFI-induced SE), criteria set 2 (p-SWE), criteria set 3 (either set 1 or 2), criteria set 4 (both set 1 and 2). Receiver operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance.
  
  
  RESULTS
  SE score ≥4 was more frequently found in malignant nodules (32/40) than in benign nodules (30/290, P<0.001). The mean SWV of malignant nodules (3.64±2.23 m/s) was significantly higher than that of benign nodules (2.02±0.69 m/s) (P<0.001). ARFI-induced SE (set 1) had a sensitivity of 80.0% (32/40) and a specificity of 89.7% (260/290) with a cut-off point of SE score ≥4; p-SWE (set 2) had a sensitivity of 80.0% (32/40) and a specificity of 57.9% (168/290) with a cut-off point of SWV ≥2.15 m/s. When ARFI-induced SE and p-SWE were combined, set 3 had the highest sensitivity (92.5%, 37/40) while set 4 had the highest specificity (95.2%, 276/290).
  
  
  CONCLUSIONS
  ARFI elastography can be used for differential diagnosis of malignant thyroid nodules without highly suspicious features on US. The combination of ARFI-induced SE and p-SWE leads to improved sensitivity and specificity.
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine Shanghai 200072, China ; Thyroid Institute, Tongji University School of Medicine Shanghai 200072, China.
authors.forename: Bo-Ji
authors.initials: BJ
authors.lastname: Liu
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine Shanghai 200072, China ; Thyroid Institute, Tongji University School of Medicine Shanghai 200072, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Lu
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine Shanghai 200072, China ; Thyroid Institute, Tongji University School of Medicine Shanghai 200072, China ; Department of Ultrasound, Guangdong Medical College Affiliated Hospital Zhanjiang 524001, China.
authors.forename: Hui-Xiong
authors.initials: HX
authors.lastname: Xu
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine Shanghai 200072, China ; Thyroid Institute, Tongji University School of Medicine Shanghai 200072, China.
authors.forename: Le-Hang
authors.initials: LH
authors.lastname: Guo
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine Shanghai 200072, China ; Thyroid Institute, Tongji University School of Medicine Shanghai 200072, China.
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Li
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine Shanghai 200072, China ; Thyroid Institute, Tongji University School of Medicine Shanghai 200072, China.
authors.forename: Xiao-Wan
authors.initials: XW
authors.lastname: Bo
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine Shanghai 200072, China ; Thyroid Institute, Tongji University School of Medicine Shanghai 200072, China.
authors.forename: Xiao-Long
authors.initials: XL
authors.lastname: Li
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine Shanghai 200072, China ; Thyroid Institute, Tongji University School of Medicine Shanghai 200072, China.
authors.forename: Yi-Feng
authors.initials: YF
authors.lastname: Zhang
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine Shanghai 200072, China ; Thyroid Institute, Tongji University School of Medicine Shanghai 200072, China.
authors.forename: Jun-Mei
authors.initials: JM
authors.lastname: Xu
authors.affiliation: Department of Ultrasound, Guangdong Medical College Affiliated Hospital Zhanjiang 524001, China.
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Xu
authors.affiliation: Thyroid Institute, Tongji University School of Medicine Shanghai 200072, China ; Department of Endocrinology and Metabolism, Shanghai Tenth People's Hospital, Tongji University School of Medicine Shanghai 200072, China.
authors.forename: Shen
authors.initials: S
authors.lastname: Qu
keywords: Ultrasound; acoustic radiation force impulse; elastography; thyroid; thyroid malignancy