Transient elastography is increasingly being used in patients with chronic liver disease. It has proven particularly useful to identify patients with advanced fibrosis or cirrhosis, while classification of no or little fibrosis appears to be difficult. In general, stiffness values <6 kPa are considered normal, whereas patients with higher levels are candidates for a disease-specific treatment or further diagnostic evaluation. Parameters influencing liver stiffness may include food intake that increases liver blood flow.
In a pilot study, transient elastography was performed in eight patients with chronic hepatitis C at fasting and serially for 180 min after intake of a standardized breakfast. Confirmatory, 56 patients and 19 controls underwent liver stiffness determination at fasting, directly after meal intake and 1 h after breakfast.
Liver stiffness significantly increased immediately after food intake for up to 60 min (P=0.01) before normalizing after 180 min. An intraindividual analysis showed a significant increase in 22 out of 43 patients with an initial liver stiffness <or=10 kPa. An increase of at least 1 kPa after food intake was found in 24 out of 43 (56%) patients with initial stiffness <or=10 kPa. Notably, nine out of 23 (39%) patients with normal initial liver stiffness (<6 kPa) had a value of >6 kPa after food intake, potentially leading to unnecessary treatment or diagnostic procedures.
Food intake increases liver stiffness in patients with hepatitis C virus infection and healthy controls. To standardize liver stiffness evaluation, we suggest measurement in the fasting condition.
"Considering that these two parameters can affect LS, differently from what reported by others   , we also analyzed their influence on the correlation between LS values in fasting conditions and the variation of LS after meal consumption, using the multiple regression analysis. In this case, we demonstrated that neither age nor transaminase levels influenced this correlation and this was true also for gender, BMI, and steatosis. "
[Show abstract][Hide abstract] ABSTRACT: Objective:
The correlation between liver stiffness (LS) variations and portal blood flow (PBF) modifications induced by a standardized liquid meal consumption and the clinical relevance of this matter are two aspects not yet fully elucidated. Herein, we evaluated the variations of LS and PBF after a standardized liquid meal intake in patients with chronic liver disease.
Material and methods:
PBF and LS were determined after an overnight fasting period in 54 patients. They were divided in three groups according to baseline LS (absent, moderate, and severe). They consumed 200 ml of water and a standardized liquid meal (300 Kcal/200 ml) after 60 min. PBF and LS were measured at 30 min after water and liquid meal consumption.
In all groups, LS and PBF values significantly increased only after meal consumption. A significant correlation between baseline LS values and post-meal increase of LS was observed. Moreover, higher basal stiffness values were associated to a larger increase of LS variation after meal consumption. The effect of the meal on LS remained statistically significant after multiple regression analysis. A significant correlation between increase of LS and PBF was found in patients with absent and moderate baseline LS. Nine patients (17%) switched from a lower to a higher level of LS after meal consumption.
A low calories/low-volume meal is capable of significantly increasing LS regardless of the grade of stiffness, determining a reclassification rate of 17%. In presence of minimal or moderate stiffness, the increase of LS is significantly correlated with the augment of PBF.
"Transient elastography is a highly reproducible and user-friendly technique , and liver stiffness measurement by transient elastography does not require a learning curve: even a novice can obtain a reliable result after a single training session . However, because liver stiffness measurements can be influenced significantly by steatosis, obesity, lower degrees of hepatic fibrosis , necroinflammation of hepatocytes , cholestasis , elevated central venous pressure , and even postprandial conditions , it should be carefully applied when used as an alternative measurement of liver stiffness instead of liver biopsy. "
[Show abstract][Hide abstract] ABSTRACT: Accurate assessment of the degree of liver fibrosis is important for estimating prognosis and deciding on an appropriate course of treatment for cases of chronic liver disease (CLD) with various etiologies. Because of the inherent limitations of liver biopsy, there is a great need for non-invasive and reliable tests that accurately estimate the degree of liver fibrosis. Ultrasound (US) elastography is considered a non-invasive, convenient, and precise technique to grade the degree of liver fibrosis by measuring liver stiffness. There are several commercial types of US elastography currently in use, namely, transient elastography, acoustic radiation force impulse imaging, supersonic shear-wave imaging, and real-time tissue elastography. Although the low reproducibility of measurements derived from operator-dependent performance remains a significant limitation of US elastography, this technique is nevertheless useful for diagnosing hepatic fibrosis in patients with CLD. Likewise, US elastography may also be used as a convenient surveillance method that can be performed by physicians at the patients' bedside to enable the estimation of the prognosis of patients with fatal complications related to CLD in a non-invasive manner.
"It is impossible to perform in patients with ascites. The liver stiffness measurements may be influenced by acute liver injury [69–71] indicated by acute aminotransferase flares, extrahepatic cholestasis , central venous pressure , beta-blockers  and food intake . TE is difficult to perform in obese patients or those with a narrow intercostal space. "
[Show abstract][Hide abstract] ABSTRACT: BackgroundWith the high prevalence of diffuse liver disease there is a strong clinical need for noninvasive detection and grading of fibrosis and steatosis as well as detection of complications.MethodsB-mode ultrasound supplemented by portal system Doppler and contrast-enhanced ultrasound are the principal techniques in the assessment of liver parenchyma and portal venous hypertension and in hepatocellular carcinoma surveillance.ResultsFibrosis can be detected and staged with reasonable accuracy using Transient Elastography and Acoustic Radiation Force Imaging. Newer elastography techniques are emerging that are undergoing validation and may further improve accuracy. Ultrasound grading of hepatic steatosis currently is predominantly qualitative.ConclusionA summary of methods including B-mode, Doppler, contrast-enhanced ultrasound and various elastography techniques, and their current performance in assessing the liver, is provided.Teaching Points• Diffuse liver disease is becoming more prevalent and there is a strong clinical need for noninvasive detection.• Portal hypertension can be best diagnosed by demonstrating portosystemic collateral venous flow.• B-mode US is the principal US technique supplemented by portal system Doppler.• B-mode US is relied upon in HCC surveillance, and CEUS is useful in the evaluation of possible HCC.• Fibrosis can be detected and staged with reasonable accuracy using TE and ARFI.• US detection of steatosis is currently reasonably accurate but grading of severity is of limited accuracy.
Insights into Imaging 05/2014; 5(4). DOI:10.1007/s13244-014-0336-2
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