Diagnostic accuracy and reliability of ultrasonography for the detection of fatty liver: A meta-analysis

Authors

  • Ruben Hernaez,

    Corresponding author
    1. Department of Medicine The Johns Hopkins School of Medicine, Baltimore, MD
    2. Department of Medicine, Washington Hospital Center, Washington, DC
    3. Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
    • Department of Medicine, The Johns School of Medicine, 2024 East Monument Street, Suite 2-600, Baltimore, MD, 21287
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    • These authors contributed equally to this work

    • fax: 410-955-0476

  • Mariana Lazo,

    1. Department of Medicine The Johns Hopkins School of Medicine, Baltimore, MD
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    • These authors contributed equally to this work

  • Susanne Bonekamp,

    1. Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD
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  • Ihab Kamel,

    1. Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD
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  • Frederick L. Brancati,

    1. Department of Medicine The Johns Hopkins School of Medicine, Baltimore, MD
    2. Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
    3. Welch Center for Prevention, Epidemiology, and Clinical Research, The Johns Hopkins University, Baltimore, MD
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  • Eliseo Guallar,

    1. Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
    2. Welch Center for Prevention, Epidemiology, and Clinical Research, The Johns Hopkins University, Baltimore, MD
    3. Department of Cardiovascular Epidemiology and Population Genetics, National Center for Cardiovascular Research (CNIC), Madrid, Spain
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  • Jeanne M. Clark

    1. Department of Medicine The Johns Hopkins School of Medicine, Baltimore, MD
    2. Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
    3. Welch Center for Prevention, Epidemiology, and Clinical Research, The Johns Hopkins University, Baltimore, MD
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  • Potential conflict of interest: Nothing to report.

  • This study was supported by the American Diabetes Association Mentor-Based Postdoctoral Fellowship Program (7-07-MN-08; to R.H. and M.L.), National Institute of Diabetes and Digestive and Kidney Diseases grant 1RO1DK083393-01A1 (to J.M.C.), and K24-DK62222 P60 DK079637 (to F.L.B.).

Abstract

Ultrasonography is a widely accessible imaging technique for the detection of fatty liver, but the reported accuracy and reliability have been inconsistent across studies. We aimed to perform a systematic review and meta-analysis of the diagnostic accuracy and reliability of ultrasonography for the detection of fatty liver. We used MEDLINE and Embase from October 1967 to March 2010. Studies that provided cross-tabulations of ultrasonography versus histology or standard imaging techniques, or that provided reliability data for ultrasonography, were included. Study variables were independently abstracted by three reviewers and double checked by one reviewer. Forty-nine (4720 participants) studies were included for the meta-analysis of diagnostic accuracy. The overall sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of ultrasound for the detection of moderate-severe fatty liver, compared to histology (gold standard), were 84.8% (95% confidence interval: 79.5-88.9), 93.6% (87.2-97.0), 13.3 (6.4-27.6), and 0.16 (0.12-0.22), respectively. The area under the summary receiving operating characteristics curve was 0.93 (0.91-0.95). Reliability of ultrasound for the detection of fatty liver showed kappa statistics ranging from 0.54 to 0.92 for intrarater reliability and from 0.44 to 1.00 for interrater reliability. Sensitivity and specificity of ultrasound was similar to that of other imaging techniques (i.e., computed tomography or magnetic resonance imaging). Statistical heterogeneity was present even after stratification for multiple clinically relevant characteristics. Conclusion: Ultrasonography allows for reliable and accurate detection of moderate-severe fatty liver, compared to histology. Because of its low cost, safety, and accessibility, ultrasound is likely the imaging technique of choice for screening for fatty liver in clinical and population settings. (HEPATOLOGY 2011; 54:1082–1090)

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