title: Solid hypo-echoic thyroid nodules on ultrasound: the diagnostic value of acoustic radiation force impulse elastography.
abstract: The aim of the study described here was to evaluate the diagnostic performance of acoustic radiation force impulse (ARFI) elastography in the differential diagnosis between benign and malignant solid hypo-echoic thyroid nodules (SHTNs) on ultrasound. In this retrospective study, 183 histologically proven SHTNs in 159 patients were enrolled. Conventional US, as well as Virtual Touch tissue imaging (VTI) and Virtual Touch tissue quantification (VTQ) of ARFI elastography, was performed on each nodule. The VTI features of SHTNs were divided into six grades, where higher grades represent harder tissue. VTQ was expressed as shear wave velocity, where higher shear wave velocity values indicate stiffer tissue. The sensitivity, specificity, accuracy, positive predictive value, negative predictive value and Youden index for ultrasound and ARFI were assessed. The 183 pathologically proven SHTNs included 117 benign and 66 malignant lesions. Nodules classified as VTI grades IV to VI were more frequently malignant (49/66, 74.2%) than benign (10/117, 8.5%) (p < 0.001). The mean shear wave velocity of VTQ for malignant SHTNs (mean ± standard deviation, 4.65 ± 2.68 m/s; range, 1.36-9 m/s) was significantly higher than that for benign SHTNs (2.34 ± 0.85 m/s, 0-5.7 m/s) (p < 0.001). The sensitivity, specificity, accuracy, positive predictive value, negative predictive value and Youden index were 27.3%-84.8%, 13.7%-89.7%, 39.3%-69.4%, 35.7%-60%, 61.5%-78.5%, and -0.015 to 0.37 for ultrasound; 68.2%, 76.9%, 73.8%, 62.5%, 81.1% and 0.451 for VTQ; and 74.2%, 91.5%, 85.2%, 83.1%, 86.3% and 0.657 for VTI, respectively. ARFI elastography performed at a superior level, compared with conventional ultrasound, in the differential diagnosis between malignant and benign SHTNs. The diagnostic performance of VTI is higher than that of VTQ.
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, Shanghai, China.
authors.forename: Jun-Mei
authors.initials: JM
authors.lastname: Xu
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, Shanghai, China. Electronic address: xuhuixiong@hotmail.com.
authors.forename: Hui-Xiong
authors.initials: HX
authors.lastname: Xu
authors.affiliation: Department of Ultrasound, Guangdong Medical College Affiliated Hospital, Zhanjiang, China.
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Xu
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, Shanghai, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, Shanghai, China.
authors.forename: Yi-Feng
authors.initials: YF
authors.lastname: Zhang
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, Shanghai, China.
authors.forename: Le-Hang
authors.initials: LH
authors.lastname: Guo
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, Shanghai, China.
authors.forename: Lin-Na
authors.initials: LN
authors.lastname: Liu
authors.affiliation: Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, Shanghai, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D016606:Thyroid Nodule / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: Acoustic radiation force impulse; Solid hypo-echoic thyroid nodule; Virtual Touch tissue imaging; Virtual Touch tissue quantification