title: How many times should we repeat measuring liver stiffness using shear wave elastography?: 5-repetition versus 10-repetition protocols.
abstract: The purpose of this study is to evaluate whether a 5-repetition liver stiffness (LS) measurement as the standard protocol of shear wave elastography (SWE) is comparable to a conventional 10-repetition measurement protocol and to identify factors that influence the reliability of the 5-repetition protocol. A total of 346 patients (mean, 48.0years; range, 15-81years, M:F=192:154) who underwent SWE were enrolled. The median, first quartile, third quartile, and interquartile range divided by the median (IQR/M) of LS measurement were calculated and compared between 5-repetition and 10-repetition protocols. Subgroup analyses were also performed to identify factors associated with measurement reliability. The overall mean LS from the 10-repetition protocol was 7.97kPa, which was not significantly different from the mean LS of the 5-repetition protocol (7.91kPa; p=0.192). However, the third quartile and IQR/M values of the two groups were significantly different from each other (p=0.003 and <0.001). Subgroup analysis revealed that the 5-repetition results were significantly different from the 10-repetition results in the fatty liver and high LS subgroups. Therefore, the 5-repetition SWE measurement protocol can replace the conventional 10-repetition protocol, with the exception of patients with fatty liver disease or an LS value higher than 10kPa.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 06351, Republic of Korea.
authors.forename: Seung Hee
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 06351, Republic of Korea. Electronic address: jeongwk@gmail.com.
authors.forename: Woo Kyoung
authors.initials: WK
authors.lastname: Jeong
authors.affiliation: Department of Radiology, Hanyang University Guri Hospital, Hanyang University College of Medicine, 153 Gyeongchun-ro, Guri-si, Gyeonggi-do 11923, Republic of Korea.
authors.forename: Yongsoo
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Radiology, Hanyang University Guri Hospital, Hanyang University College of Medicine, 153 Gyeongchun-ro, Guri-si, Gyeonggi-do 11923, Republic of Korea.
authors.forename: Sanghyeok
authors.initials: S
authors.lastname: Lim
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 06351, Republic of Korea.
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Kwon
authors.affiliation: Department of Internal Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, 153 Gyeongchun-ro, Guri-si, Gyeonggi-do 11923, Republic of Korea.
authors.forename: Tae Yeob
authors.initials: TY
authors.lastname: Kim
authors.affiliation: Department of Radiology, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, 7 Keunjaebong-gil, Hwaseong-si, Gyeonggi-do 18450, Republic of Korea.
authors.forename: Min Yeong
authors.initials: MY
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, 153 Gyeongchun-ro, Guri-si, Gyeonggi-do 11923, Republic of Korea.
authors.forename: Joo Hyun
authors.initials: JH
authors.lastname: Sohn
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D019233:Retreatment; D012189:Retrospective Studies
keywords: Diffuse liver disease; Intra-observer variation; Liver stiffness measurement; Shear wave elastography