title: Acoustic radiation force impulse elastography of the liver in healthy patients: test location, reference range and influence of gender and body mass index.
abstract: The objective of this study was to evaluate the best test location and study factors associated with acoustic radiation force impulse (ARFI) elastography measurements in healthy individuals. When ARFI elastography was performed on 68 healthy patients after controlling for all known test condition factors except segmental location, the median shear wave velocities (SWVs) derived from five valid measurements in the area between S5 and S8 in patients in the supine position had a significantly lower mean and the narrowest 95% confidence interval, followed by those for the S8 supine and S8 semidecubitus locations (p = 0.045). Analysis of mean SWVs revealed similar, although statistically insignificant, findings (p = 0.078). Male patients had significantly higher median SWVs (p = 0.0073) and mean SWVs (p = 0.0043) than female patients. Patients with body mass indexes >22 had significantly lower median SWVs (p = 0.0033) and mean SWVs (p = 0.0008) than those with body mass indexes ≤22. S5/8 supine was the better test location for ARFI. The reference ranges for median and mean SWV were 0.81-1.27 and 0.82-1.27 m/s, respectively. Gender and body mass index, but not age, were the significant factors associated with ARFI SWV values.
authors: Liver Center, Department of Gastroenterology, Taipei City Hospital Renai Branch, Taipei, Taiwan, Republic of China. Electronic address: gracely@tpech.gov.tw.
authors: Li-Ying
authors: LY
authors: Liao
authors: Department of Family Medicine, Taipei City Hospital Renai Branch, Taipei, Taiwan, Republic of China.
authors: Kuan-Liang
authors: KL
authors: Kuo
authors: Liver Center, Department of Gastroenterology, Taipei City Hospital Renai Branch, Taipei, Taiwan, Republic of China.
authors: Huei-Shin
authors: HS
authors: Chiang
authors: Liver Center, Department of Gastroenterology, Taipei City Hospital Renai Branch, Taipei, Taiwan, Republic of China.
authors: Chong-Zong
authors: CZ
authors: Lin
authors: Taipei Databank for Public Health Analysis, Institute of Clinical Research and Training, Taipei City Hospital, Taipei, Taiwan, Republic of China.
authors: Yi-Ping
authors: YP
authors: Lin
authors: Liver Center, Department of Gastroenterology, Taipei City Hospital Renai Branch, Taipei, Taiwan, Republic of China.
authors: Chih-Lin
authors: CL
authors: Lin
mesh_terms: D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D011446:Prospective Studies
keywords: Acoustic radiation force impulse; Age; Body mass index; Elastography; Gender; Liver fibrosis; Reference range; Shear wave