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Canadian Journal of Gastroenterology and Hepatology
Volume 28 (2014), Issue 3, Pages 143-149
http://dx.doi.org/10.1155/2014/952684
Original Article

The Feasibility and Reliability of Transient Elastography Using Fibroscan®: A Practice Audit of 2335 Examinations

Jack XQ Pang,1,2 Faruq Pradhan,1 Scott Zimmer,3 Sophia Niu,3 Pam Crotty,1 Jenna Tracey,1 Christopher Schneider,1 Steven J Heitman,1,2 Gilaad G Kaplan,1,2 Mark G Swain,1 and Robert P Myers1,2

1Liver Unit, Division of Gastroenterology and Hepatology, Department of Medicine, University of Calgary, Canada
2Department of Community Health Sciences, University of Calgary, Canada
3Medical Services, Alberta Health Services, Calgary, Alberta, Canada

Received 28 October 2013; Accepted 11 November 2013

Copyright © 2014 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

BACKGROUND: Liver stiffness measurement (LSM) using transient elastography is widely used in the management of patients with chronic liver disease.

OBJECTIVES: To examine the feasibility and reliability of LSM, and to identify patient and operator characteristics predictive of poorly reliable results.

METHODS: The present retrospective study investigated the frequency and determinants of poorly reliable LSM (interquartile range [IQR]/median LSM [IQR/M] >30% with median liver stiffness ≥7.1 kPa) using the FibroScan (Echosens, France) over a three-year period. Two experienced operators performed all LSMs. Multiple logistic regression analyses examined potential predictors of poorly reliable LSMs including age, sex, liver disease, the operator, operator experience (<500 versus ≥500 scans), FibroScan probe (M versus XL), comorbidities and liver stiffness. In a subset of patients, medical records were reviewed to identify obesity (body mass index ≥30 kg/m2).

RESULTS: Between July 2008 and June 2011, 2335 patients with liver disease underwent LSM (86% using the M probe). LSM failure (no valid measurements) occurred in 1.6% (n=37) and was more common using the XL than the M probe (3.4% versus 1.3%; P=0.01). Excluding LSM failures, poorly reliable LSMs were observed in 4.9% (n=113) of patients. Independent predictors of poorly reliable LSM included older age (OR 1.03 [95% CI 1.01 to 1.05]), chronic pulmonary disease (OR 1.58 [95% CI 1.05 to 2.37), coagulopathy (OR 2.22 [95% CI 1.31 to 3.76) and higher liver stiffness (OR per kPa 1.03 [95% CI 1.02 to 1.05]), including presumed cirrhosis (stiffness ≥12.5 kPa; OR 5.24 [95% CI 3.49 to 7.89]). Sex, diabetes, the underlying liver disease and FibroScan probe were not significant. Although reliability varied according to operator (P<0.0005), operator experience was not significant. In a subanalysis including 434 patients with body mass index data, obesity influenced the rate of poorly reliable results (OR 2.93 [95% CI 0.95 to 9.05]; P=0.06).

CONCLUSIONS: FibroScan failure and poorly reliable LSM are uncommon. The most important determinants of poorly reliable results are older age, obesity, higher liver stiffness and the operator, the latter emphasizing the need for adequate training.