title: Comparison of the Reliability of Acoustic Radiation Force Impulse Imaging and Supersonic Shear Imaging in Measurement of Liver Stiffness.
abstract: OBJECTIVE
  To compare the reliability of acoustic radiation force impulse (ARFI) imaging and supersonic shear imaging (SSI) in measurement of liver stiffness.
  
  
  METHODS
  This study was approved by the institutional review board, and written informed consent was obtained for all patients. Seventy-nine patients (25 healthy patients, 26 with Child-Pugh class A, and 28 with Child-Pugh class B or C) were enrolled and analyzed from April 2012 to April 2013. In each patient, three abdominal radiologists performed nine measurements of hepatic shear-wave speed with both ARFI imaging and SSI on the same day. Four weeks later, a second session was performed with the same protocol. Interobserver and intraobserver agreements were calculated by using intraclass correlation coefficients. Technical failures and measurement time were evaluated.
  
  
  RESULTS
  There were four technical failures in the SSI group and one in the ARFI group (P = .375). The overall interobserver agreement of ARFI imaging was significantly higher than that of SSI (0.941 vs 0.828, P < .001). The overall intraobserver agreement of ARFI imaging was significantly higher than that of SSI (0.915 vs 0.829, P < .001). The overall shear-wave speed measured with SSI was higher than that measured with ARFI imaging (2.04 m/sec ± 0.88 vs 1.80 m/sec ± 0.81, P < .001). The measurement time of SSI was longer than that of ARFI imaging (310.8 seconds ± 88.5 vs 84.5 seconds ± 15.4, P < .001).
  
  
  CONCLUSIONS
  ARFI imaging was more reliable than SSI in measurement of liver stiffness. The hepatic shear-wave speed measured with SSI was higher than that measured with ARFI imaging, which means that the shear-wave speeds measured with ARFI imaging and SSI cannot be used interchangeably.
authors.affiliation: From the Departments of Radiology (H.W.) and Internal Medicine (W.K.), SMG-SNU Boramae Medical Center, Seoul, Korea; and Departments of Radiology (J.Y.L., J.H.Y., B.I.C.) and Family Medicine (B.C.), Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea.
authors.forename: Hyunsik
authors.initials: H
authors.lastname: Woo
authors.affiliation: From the Departments of Radiology (H.W.) and Internal Medicine (W.K.), SMG-SNU Boramae Medical Center, Seoul, Korea; and Departments of Radiology (J.Y.L., J.H.Y., B.I.C.) and Family Medicine (B.C.), Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Lee
authors.affiliation: From the Departments of Radiology (H.W.) and Internal Medicine (W.K.), SMG-SNU Boramae Medical Center, Seoul, Korea; and Departments of Radiology (J.Y.L., J.H.Y., B.I.C.) and Family Medicine (B.C.), Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea.
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Yoon
authors.affiliation: From the Departments of Radiology (H.W.) and Internal Medicine (W.K.), SMG-SNU Boramae Medical Center, Seoul, Korea; and Departments of Radiology (J.Y.L., J.H.Y., B.I.C.) and Family Medicine (B.C.), Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea.
authors.forename: Won
authors.initials: W
authors.lastname: Kim
authors.affiliation: From the Departments of Radiology (H.W.) and Internal Medicine (W.K.), SMG-SNU Boramae Medical Center, Seoul, Korea; and Departments of Radiology (J.Y.L., J.H.Y., B.I.C.) and Family Medicine (B.C.), Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea.
authors.forename: Belong
authors.initials: B
authors.lastname: Cho
authors.affiliation: From the Departments of Radiology (H.W.) and Internal Medicine (W.K.), SMG-SNU Boramae Medical Center, Seoul, Korea; and Departments of Radiology (J.Y.L., J.H.Y., B.I.C.) and Family Medicine (B.C.), Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea.
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D003952:Diagnostic Imaging / Q000379:methods*; D054459:Elasticity Imaging Techniques; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D033081:Shear Strength