Quantification of Liver Steatosis

Abstract

The prevalence of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) is increasing in the modern world. Fatty infiltration of the liver can be assessed by standard ultrasound, by controlled attenuation parameter (CAP) using the FibroScan device or, more recently, by ultrasound systems that evaluate the attenuation in the liver. Standard ultrasound (US) for steatosis evaluation was used for a long time as a semi-quantitative method for steatosis assessment in the liver. A "bright liver" with "posterior attenuation" is the typical US sign of liver steatosis. Considering the attenuation severity, steatosis is subjectively graded as mild, moderate or severe. Using the kidney/liver ratio, a more accurate evaluation can be made. Controlled attenuation parameter (CAP) was developed by EchoSens, France, and implemented into the FibroScan device. CAP manages an objective assessment of steatosis severity with rather good accuracy. More recently, ultrasound companies such as Hitachi, General Electric and Canon, implemented in their system algorithms which allow an objective assessment of liver steatosis, using the attenuation of the ultrasound beams.

Hepatic steatosis: Ultrasound assessment using attenuation imaging (ATI) with liver biopsy correlation

“…16 Attenuation imaging is available from multiple manufacturers: Aixplorerattenuation parameter, Canonattenuation imaging (ATI), General Electricultrasound-guided attenuation parameter (UGAP) and Hitachi -attenuation coefficient (ATT). 8 ATT has been shown to be equivalent to CAP, but better when SCD >2 cm. 19 ATI is the best assessed attenuation imaging technique, with good intra-and inter-observer reproducibility.…”

“…MRI-PDFF has a high grading accuracy for hepatic steatosis with area under curve (AUC) of 0.99. 8 It is currently the noninvasive reference standard for liver fat assessment and can also quantify liver iron content. 9 MRI disadvantages are lack of widespread PDFF sequence software availability and cost.…”

“…10,12,14,15 The standard quantitative sonographic method measures ultrasound beam attenuation with depth. 8 The most widely used method is the controlled attenuation parameter (CAP) from FibroScan (Paris, France). 16 Usually utilised by Hepatologists, this is obtained simultaneously with fibrosis assessment using Transient Elastography (TE).…”

A plea for a unified approach to sedation in gastrointestinal endoscopy in Romania: results from a prospective multicentric trial

“…Despite the clear benefit of sedation in digestive endoscopy, practices in Romania are highly heterogeneous as healthcare professionals' participation in this process is not clearly regulated by local authorities. In addition to this, there seem to be significant differences among centers [4,5] regarding the types and dosages of drugs, used as well as protocols for patient monitoring during and after sedation.…”