title: Measurement of real-time tissue elastography in a phantom model and comparison with transient elastography in pediatric patients with liver diseases.
abstract: OBJECTIVE
  We aimed to determine the comparability of real-time tissue elastography (RTE) and transient elastography (TE) in pediatric patients with liver diseases.
  
  
  METHODS
  RTE was performed on the Elasticity QA Phantom Model 049 (Computerized Imaging Reference Systems Company Inc., Norfolk, Virginia, USA), which has five areas with different levels of stiffness. RTE measurements of relative stiffness (MEAN [mean value of tissue elasticity], AREA [% of blue color-coded stiffer tissue]) in the phantom were compared with the phantom stiffness specified in kPa (measurement unit of TE). RTE and TE were performed on 147 pediatric patients with various liver diseases. A total of 109 measurements were valid. The participants had following diseases: metabolic liver disease (n=25), cystic fibrosis (n=20), hepatopathy of unknown origin (n=11), autoimmune hepatitis (n=12), Wilson's disease (n=11), and various liver parenchyma alterations (n=30). Correlations between RTE and TE measurements in the patients were calculated. In addition, RTE was performed on a control group (n=30), and the RTE values between the patient and control groups were compared.
  
  
  RESULTS
  The RTE parameters showed good correlation in the phantom model with phantom stiffness (MEAN/kPa, r=-0.97; AREA/kPa, r=0.98). However, the correlation of RTE and TE was weak in the patient group (MEAN/kPa, r=-0.23; AREA/kPa, r=0.24). A significant difference was observed between the patient and control groups (MEAN, P = 5.32 e-7; AREA, P = 1.62 e-6).
  
  
  CONCLUSIONS
  In the phantom model, RTE was correlated with kPa, confirming the presumed comparability of the methods. However, there was no direct correlation between RTE and TE in patients with defined liver diseases under real clinical conditions.
authors: From the Division of Pediatric Radiology (J-P.S., S.E.S., B.S. e-mail: buketselmi@gmail.com), Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany; the Department of Pediatric Radiology (G.A., V.K.), University Clinic Giessen & Marburg, Giessen, Germany; the Department of General Pediatrics (U.T., G.E.), University Hospital of Heidelberg, Germany.
authors: Jens-Peter
authors: JP
authors: Schenk
authors: Gerhard
authors: G
authors: Alzen
authors: Volker
authors: V
authors: Klingmüller
authors: Ulrike
authors: U
authors: Teufel
authors: Saroa
authors: S
authors: El Sakka
authors: Guido
authors: G
authors: Engelmann
authors: Buket
authors: B
authors: Selmi
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003199:Computer Systems; D054459:Elasticity Imaging Techniques / Q000295:instrumentation; D005260:Female; D006801:Humans; D007223:Infant; D008107:Liver Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008962:Models, Theoretical; D019047:Phantoms, Imaging; D055815:Young Adult