Quantitative assessment of liver fat with magnetic resonance imaging and spectroscopy
TL;DR: Magnetic resonance (MR) techniques can decompose the liver signal into its fat and water signal components and therefore assess liver fat more directly than CT or US and are likely to be commercially available soon.
Abstract: Hepatic steatosis is characterized by abnormal and excessive accumulation of lipids within hepatocytes. It is an important feature of diffuse liver disease, and the histological hallmark of non-alcoholic fatty liver disease (NAFLD). Other conditions associated with steatosis include alcoholic liver disease, viral hepatitis, HIV and genetic lipodystrophies, cystic fibrosis liver disease, and hepatotoxicity from various therapeutic agents. Liver biopsy, the current clinical gold standard for assessment of liver fat, is invasive and has sampling errors, and is not optimal for screening, monitoring, clinical decision making, or well-suited for many types of research studies. Non-invasive methods that accurately and objectively quantify liver fat are needed. Ultrasound (US) and computed tomography (CT) can be used to assess liver fat but have limited accuracy as well as other limitations. Magnetic resonance (MR) techniques can decompose the liver signal into its fat and water signal components and therefore assess liver fat more directly than CT or US. Most magnetic resonance (MR) techniques measure the signal fat-fraction (the fraction of the liver MR signal attributable to liver fat), which may be confounded by numerous technical and biological factors and may not reliably reflect fat content. By addressing the factors that confound the signal fat-fraction, advanced MR techniques measure the proton density fat-fraction (the fraction of the liver proton density attributable to liver fat), which is a fundamental tissue property and a direct measure of liver fat content. These advanced techniques show promise for accurate fat quantification and are likely to be commercially available soon.
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TL;DR: This guidance provides a data-supported approach to the diagnostic, therapeutic, and preventive aspects of NAFLD care.
4,431 citations
TL;DR: A narrative review focuses on the rapidly expanding body of clinical evidence that supports the concept of NAFLD as a multisystem disease and the factors linkingNAFLD with other extra-hepatic chronic diseases, such as T2DM, CVD, cardiac diseases and CKD.
1,897 citations
TL;DR: How to identify patients with nonalcoholic fatty liver disease at greatest risk of non Alcoholic steatohepatitis and cirrhosis is illustrated and the role and limitations of current diagnostics and liver biopsy are discussed to provide an outline for the management of patients across the spectrum of non alcoholic fatty Liver disease.
Abstract: Importance Nonalcoholic fatty liver disease and its subtype nonalcoholic steatohepatitis affect approximately 30% and 5%, respectively, of the US population. In patients with nonalcoholic steatohepatitis, half of deaths are due to cardiovascular disease and malignancy, yet awareness of this remains low. Cirrhosis, the third leading cause of death in patients with nonalcoholic fatty liver disease, is predicted to become the most common indication for liver transplantation. Objectives To illustrate how to identify patients with nonalcoholic fatty liver disease at greatest risk of nonalcoholic steatohepatitis and cirrhosis; to discuss the role and limitations of current diagnostics and liver biopsy to diagnose nonalcoholic steatohepatitis; and to provide an outline for the management of patients across the spectrum of nonalcoholic fatty liver disease. Evidence Review PubMed was queried for published articles through February 28, 2015, using the search termsNAFLD and cirrhosis, mortality, biomarkers,andtreatment. A total of 88 references were selected, including 14 randomized clinical trials, 19 cohort or case-control studies, 1 population-based study, 2 practice guidelines, 7 meta-analyses, 43 classified as other, and 2 webpages. Findings Sixty-six percent of patients older than 50 years with diabetes or obesity are thought to have nonalcoholic steatohepatitis with advanced fibrosis. Even though the ability to identify the nonalcoholic steatohepatitis subtype within those with nonalcoholic fatty liver disease still requires liver biopsy, biomarkers to detect advanced fibrosis are increasingly reliable. Lifestyle modification is the foundation of treatment for patients with nonalcoholic steatosis. Available treatments with proven benefit include vitamin E, pioglitazone, and obeticholic acid; however, the effect size is modest ( Conclusions and Relevance Between 75 million and 100 million individuals in the United States are estimated to have nonalcoholic fatty liver disease and its potential morbidity extends beyond the liver. It is important that primary care physicians, endocrinologists, and other specialists be aware of the scope and long-term effects of the disease. Early identification of patients with nonalcoholic steatohepatitis may help improve patient outcomes through treatment intervention, including transplantation for those with decompensated cirrhosis.
1,743 citations
TL;DR: The current state of the noninvasive assessment of liver disease in NAFLD is summarized, and an expert synthesis of how these nonin invasive tools could be utilized in clinical practice is provided.
780 citations
TL;DR: Alcohol-related liver disease, alcohol-related steatohepatitis, and alcohol- related cirrhosis are suggested, retaining the familiar abbreviations (ALD, ASH, and AC, respectively), due to longstanding usage, the term alcoholic hepatitis will likely persist.
441 citations
References
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TL;DR: There are no systems for grading necroinflammatory activity or for staging fibrosis as exist for various other forms of chronic liver disease and this study proposes a grading and staging system that reflects the unique histological features of nonalcoholic steatohepatitis.
3,553 citations
TL;DR: The outcome of cirrhosis and liver-related death is not uniform across the spectrum of nonalcoholic fatty liver, and poor outcomes are more frequent in patients in whom biopsies show ballooning degeneration and Mallory hyaline or fibrosis.
3,167 citations
TL;DR: Mortality among community-diagnosed NAFLD patients is higher than the general population and is associated with older age, impaired fasting glucose, and cirrhosis, although the absolute risk is low.
2,681 citations
Journal Article•
TL;DR: Findings in 20 patients with nonalcoholic steatohepatitis of unknown cause found the patients were moderately obese, and many had obesity-associated diseases, such as diabetes mellitus and cholelithiasis.
2,484 citations
TL;DR: It is suggested that a length of at least 25 mm is necessary to evaluate fibrosis accurately with a semiquantitative score, because variability in the distribution of fibrosis within the liver is a major limitation when using more accurate methods such as automated image analysis.
2,207 citations