title: Diagnostic role of conventional ultrasonography and shearwave elastography in asymptomatic patients with diffuse thyroid disease: initial experience with 57 patients.
abstract: OBJECTIVE
  Thyroid ultrasonography (US) is a useful diagnostic tool in the evaluation of diffuse thyroid disease (DTD), whereas shearwave elastography is a dynamic technique that can provide information about tissue hardness by using acoustic shearwaves remotely induced by a focused ultrasonic beam. This study aims at investigating the role of conventional US and shearwave elastography in the diagnosis of asymptomatic patients with DTD.
  
  
  METHODS
  Fifty-seven patients who underwent both conventional US and shearwave elastography were included in this study. Interobserver variability of the three radiologists in assessment of underlying thyroid echogenicity on conventional US was analyzed. Diagnostic performances for diagnosing DTD on conventional US and shearwave elastography were calculated and compared.
  
  
  RESULTS
  Fair agreement was observed in the identification of DTD with conventional US (kappa value= 0.27). The area under the receiver operating characteristic curve (Az) were 0.52-0.585 on conventional US by three radiologists. The Az values when using the mean and maximum elasticity values as a diagnostic criteria for DTD were 0.619 and 0.59 on shearwave elastography. Patients with DTD showed higher mean [24.1±10 kilo-Pascals (kPa)] and maximum (36.4±13.3 kPa) elasticity values on shearwave elastography when compared to the normal group (23.4±10.8 kPa and 33.7±12.4 kPa, respectively), although without statistical significance (p=0.802 and p=0.452, respectively).
  
  
  CONCLUSIONS
  Conventional US did not show reliable interobserver agreement in the diagnosis of DTD. Although not statistically significant, shearwave elastography may provide additional information in the diagnosis of DTD. Therefore, larger prospective studies are needed to define the values of shearwave elastography for diagnosing DTD.
authors: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea. docjin@yuhs.ac.
authors: Injoong
authors: I
authors: Kim
authors: Eun-Kyung
authors: EK
authors: Kim
authors: Jung Hyun
authors: JH
authors: Yoon
authors: Kyung Hwa
authors: KH
authors: Han
authors: Eun Ju
authors: EJ
authors: Son
authors: Hee Jung
authors: HJ
authors: Moon
authors: Jin Young
authors: JY
authors: Kwak
mesh_terms: D000328:Adult; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013959:Thyroid Diseases / Q000000981:diagnostic imaging*; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*
keywords: Ultrasonography; diffuse thyroid disease; shearwave elastography; thyroid gland