Non-invasive means of measuring hepatic fat content

Abstract

Hepatic steatosis affects 20% to 30% of the general adult population in the western world. Currently, the technique of choice for determining hepatic fat deposition and the stage of fibrosis is liver biopsy. However, it is an invasive procedure and its use is limited, particularly in children. It may also be subject to sampling error. Non-invasive techniques such as ultrasound, computerised tomography (CT), magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy ((1)H MRS) can detect hepatic steatosis, but currently cannot distinguish between simple steatosis and steatohepatitis, or stage the degree of fibrosis accurately. Ultrasound is widely used to detect hepatic steatosis, but its sensitivity is reduced in the morbidly obese and also in those with small amounts of fatty infiltration. It has been used to grade hepatic fat content, but this is subjective. CT can detect hepatic steatosis, but exposes subjects to ionising radiation, thus limiting its use in longitudinal studies and in children. Recently, magnetic resonance (MR) techniques using chemical shift imaging have provided a quantitative assessment of the degree of hepatic fatty infiltration, which correlates well with liver biopsy results in the same patients. Similarly, in vivo (1)H MRS is a fast, safe, non-invasive method for the quantification of intrahepatocellular lipid (IHCL) levels. Both techniques will be useful tools in future longitudinal clinical studies, either in examining the natural history of conditions causing hepatic steatosis (e.g. non-alcoholic fatty liver disease), or in testing new treatments for these conditions.

Clinical and laboratory characteristics associated with dyslipidemia and liver steatosis in chronic HBV carriers

“…Among a sample of 90 Brazilian obese adolescents, the prevalence of LS on ultrasound was 15.5% 19 . Hepatic ultrasound is a simple, noninvasive technique that is widely used in clinical practice to detect fatty infi ltration of the liver 20 . Several studies have assessed the sensitivity and specifi city of ultrasound for detecting LS.…”

Noninvasive quantification of hepatic steatosis inrats using 3.0 T 1H‐magnetic resonance spectroscopy

“…Noninvasive modalities such as ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) have been employed for the assessment of hepatic steatosis (11)(12)(13). However, these modalities do not specifically measure hepatic fat content, are semiquantitative, and lack high sensitivity and specificity (13).…”

Correlation of NAFLD fibrosis score and BARD score with ultrasonographic evidence of nonalcoholic fatty liver disease in overweight patients: A prospective study

“…Overall, USG has a reported sensitivity of 60-94% and a specifi city of 84-95% for detecting fat, [1] but combined fat and fi brosis can show up a hyperechoic liver in 98.7% of patients known as 'fatty fi brotic pattern'. Sensitivity depends on the amount of fat in liver, however, both sensitivity and specifi city are poor in morbid obesity.…”

“…On USG, fatty liver is seen as a bright liver with echogenicity Abstract of liver more than the right kidney. Overall, USG has a sensitivity of 60-94% and a specifi city of 84-95% for detecting fat, [1] NAFLD fi brosis score and BARD score are two of the many noninvasive scoring systems used in the evaluation of the fi brosis in patients of NALFD biochemically.…”