title: Prospective Comparison of Liver Stiffness Measurements between Two Point Shear Wave Elastography Methods: Virtual Touch Quantification and Elastography Point Quantification.
abstract: To prospectively compare technical success rate and reliable measurements of virtual touch quantification (VTQ) elastography and elastography point quantification (ElastPQ), and to correlate liver stiffness (LS) measurements obtained by the two elastography techniques.
  
  
  
  Our study included 85 patients, 80 of whom were previously diagnosed with chronic liver disease. The technical success rate and reliable measurements of the two kinds of point shear wave elastography (pSWE) techniques were compared by χ(2) analysis. LS values measured using the two techniques were compared and correlated via Wilcoxon signed-rank test, Spearman correlation coefficient, and 95% Bland-Altman limit of agreement. The intraobserver reproducibility of ElastPQ was determined by 95% Bland-Altman limit of agreement and intraclass correlation coefficient (ICC).
  
  
  
  The two pSWE techniques showed similar technical success rate (98.8% for VTQ vs. 95.3% for ElastPQ, p = 0.823) and reliable LS measurements (95.3% for VTQ vs. 90.6% for ElastPQ, p = 0.509). The mean LS measurements obtained by VTQ (1.71 ± 0.47 m/s) and ElastPQ (1.66 ± 0.41 m/s) were not significantly different (p = 0.209). The LS measurements obtained by the two techniques showed strong correlation (r = 0.820); in addition, the 95% limit of agreement of the two methods was 27.5% of the mean. Finally, the ICC of repeat ElastPQ measurements was 0.991.
  
  
  
  Virtual touch quantification and ElastPQ showed similar technical success rate and reliable measurements, with strongly correlated LS measurements. However, the two methods are not interchangeable due to the large limit of agreement.
authors: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.
authors: Hyunsuk
authors: H
authors: Yoo
authors: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.; Institute of Radiation Medicine, Seoul National University Hospital, Seoul 03080, Korea.
authors: Jeong Min
authors: JM
authors: Lee
authors: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.
authors: Jeong Hee
authors: JH
authors: Yoon
authors: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.
authors: Dong Ho
authors: DH
authors: Lee
authors: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.
authors: Won
authors: W
authors: Chang
authors: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.; Institute of Radiation Medicine, Seoul National University Hospital, Seoul 03080, Korea.
authors: Joon Koo
authors: JK
authors: Han
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D012720:Severity of Illness Index
keywords: Liver fibrosis; Liver stiffness; Shear wave elastography; Ultrasound elastography