Diffuse Liver Disease Research Articles

Modern views on the diagnosis of sarcopenia in patients with diffuse liver diseases

Currently, the term sarcopenia is primarily understood as a decrease in muscle strength as a key characteristic of sarcopenia, taking into account that the most unfavorable clinical outcomes occur in patients with a combination of impaired muscle strength and function. In particular, grip strength combined with evaluation of the end-stage liver disease (MELD) model is the best predictive model among widely used methods for diagnosing sarcopenia in patients with cirrhosis of the liver. Given that muscle mass does not always correlate well with muscle strength or function in the population of patients with cirrhosis of the liver, there is a need for a comprehensive diagnosis of sarcopenia based on a combination of functional research methods with modern instrumental methods. The presented review article highlights current information on the diagnosis of sarcopenia in patients with chronic diffuse liver diseases. Aspects of antrometric methods, functional tests, methods for evaluating muscle strength and mass, and physical performance are reflected. Special attention is paid to the advantages of modern methods of instrumental diagnosis of sarcopenia in patients with diffuse liver diseases. The advantages and disadvantages of each of the methods of instrumental diagnostics are noted.

The effect of stress on liver function

«Psychosocial stress» is becoming an increasingly common concept in today’s complex and highly demanding society. Although the liver is one of the body’s most resilient organs, it is still vulnerable to the damaging effects of stress and aging, leading to liver disease, severe scarring and impaired function. Mental stress increases mortality from liver disease. Stressors activate macrophages and trigger an innate immune response, which then leads to the induction of inflammation and liver damage. In its diseases, symptoms such as low energy, fatigue, changes in employment status and functionality can also lead to the development of depression. The various physiological effects of glucocorticoids and catecholamines released into the bloodstream during stress lead to inflammation and oxidative stress in the liver. Research has explained the complex interactions that occur between stress system effectors and inflammation. Chronic psychological stress leads to an increase in serum glucocorticoid concentrations and the release of catecholamines, which increases the need for insulin. Insulin resistance leads to the development of metabolic-associated steatotic liver disease. The high prevalence of hepatogenic fatigue in chronic diffuse liver disease, its negative impact on the quality of life of patients, and the lack of effect of basic treatment lead to its aggravation due to stress. Sublingual S-adenosyl-L-methionine is effective in the treatment of hepatogenic stress fatigue, both in short-term and long-term use as part of the complex therapy of liver diseases.

Simultaneous whole-liver water and mapping with isotropic resolution during free-breathing.

To develop and validate a data acquisition scheme combined with a motion-resolved reconstruction and dictionary-matching-based parameter estimation to enable free-breathing isotropic resolution self-navigated whole-liver simultaneous water-specific ( ) and ( ) mapping for the characterization of diffuse and oncological liver diseases. The proposed data acquisition consists of a magnetization preparation pulse and a two-echo gradient echo readout with a radial stack-of-stars trajectory, repeated with different preparations to achieve different and contrasts in a fixed acquisition time of 6 min. Regularized reconstruction was performed using self-navigation to account for motion during the free-breathing acquisition, followed by water-fat separation. Bloch simulations of the sequence were applied to optimize the sequence timing for insensitivity at 3 T, to correct for relaxation-induced blurring, and to map and using a dictionary. The proposed method was validated on a water-fat phantom with varying relaxation properties and in 10 volunteers against imaging and spectroscopy reference values. The performance and robustness of the proposed method were evaluated in five patients with abdominal pathologies. Simulations demonstrate good insensitivity of the proposed method in measuring and values. The proposed method produces co-registered and maps with a good agreement with reference methods (phantom: ; ). The proposed and mapping exhibits good repeatability and can be robustly performed in patients with pathologies. The proposed method allows whole-liver and quantification with high accuracy at isotropic resolution in a fixed acquisition time during free-breathing.

Quantitative Liver Imaging in Children.

In children and adults, quantitative imaging examinations determine the effectiveness of treatment for liver disease. However, pediatric liver disease differs in presentation from liver disease in adults. Children also needed to be followed for a longer period from onset and have less control of their bodies, showing more movement than adults during imaging examinations, which leads to a greater need for sedation. Thus, it is essential to appropriately tailor and accurately perform noninvasive imaging tests in these younger patients. This article is an overview of updated imaging techniques used to assess liver disease quantitatively in children. The common initial imaging study for diffuse liver disease in pediatric patients is ultrasound. In addition to preexisting echo analysis, newly developed attenuation imaging techniques have been introduced to evaluate fatty liver. Ultrasound elastography is also now actively used to evaluate liver conditions, and the broad age spectrum of the pediatric population requires caution to be taken even in the selection of probes. Magnetic resonance imaging (MRI) is another important imaging tool used to evaluate liver disease despite requiring sedation or anesthesia in young children because it allows quantitative analysis with sequences such as fat analysis and MR elastography. In addition to ultrasound and MRI, we review quantitative imaging methods specifically for fatty liver, Wilson disease, biliary atresia, hepatic fibrosis, Fontan-associated liver disease, autoimmune hepatitis, sinusoidal obstruction syndrome, and the transplanted liver. Lastly, concerns such as growth and motion that need to be addressed specifically for children are summarized.

Influence of age, body mass index and gender on sonographic indicators of the liver in patients with metabolic dysfunction-associated steatotic liver disease

Background. The incidence of metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing along with the increasing prevalence of obesity. There are close relationships between these two pathologies due to the functioning of adipose tissue as an endocrine organ with a complex influence on various metabolic processes. It is known that premenopausal women are less prone to fatty liver disease than men. The aim was to study the influence of gender, body mass index (BMI) and age on sonographic indicators and the degree of liver steatosis in patients with metabolic dysfunction-associated steatotic liver disease. Materials and methods. Ninety-two patients with MASLD were included in the study, 48 women and 44 men. Inclusion criterion was metabolic dysfunction-associated steatotic liver disease, exclusion criteria were any non-metabolic factors of chronic diffuse liver disease. Patients were divided into groups by gender and age. Women were divided by age according to the presence and absence of menopause, men were divided into groups below and above 45 years — the conventional age of the beginning of the decline in gonadotropic function. The analysis of structural changes of the liver, namely the assessment of the size, contours, structure, echogenicity, and visualization of blood vessels in the B-mode was carried out with the help of ultrasound examination on Toshiba Xario 660 (Japan). The degree of steatosis was assessed by the controlled attenuation parameter. Results. In men, the right, left and caudate liver lobes were significantly larger (p < 0.05) than in women, which is due to the higher weight of men in the absence of a difference in the BMI. There was no significant difference between men and women in degree of steatosis (p > 0.05). A moderate positive correlation (r = 0.63) was found between BMI and the controlled attenuation parameter; in women, there was no connection between these indicators. Analysis of correlations in women of different ages, divided by the presence of menopause, found that before menopause, there was no dependence of steatosis indicators on BMI, while with the onset of menopause, the coefficient of correlation between these indicators was 0.39 (р < 0.02). Conclusions. No significant difference was found between the frequency of various degrees of steatosis in MASLD according to the controlled attenuation parameter in men and women. There was a dependence of the severity of liver steatosis on the BMI in men, the dependence of steatosis on the body mass index in women was manifested starting from the menopause period, which suggests the protective role of female sex hormones.

Liver non-contrast perfusion in diffuse liver diseases diagnostic algorithm: the new diagnostic criteria

Purpose: to define the new criteria for contrast-free ASL perfusion using for the management of diffuse liver diseases (DLD).Material and methods. Clinical and laboratory data, results of MRI with non-contrast MR perfusion (ASL-perfusion) of the liver were estimated in a group of patients with DLD (three-year research).Results. Potentials of assessment of liver ASL perfusion for patients with DLD (including complicated cases) are described in the article. It was established that ASL liver perfusion is useful for DLD clinical forms differential diagnosis, predicting the risk of liver cirrhosis, as well as complications (hepatic encephalopathy, sialoadenitis) and DLD exacerbation. The strategy of contrast-free MR perfusion using in patients with DLD management algorithm was developed.Conclusion. Liver ASL perfusion is a promising for the study and application method for the management of DLD.

Multiparametric magnetic resonance imaging of the liver and spleen in Gaucher disease.

To assess liver and spleen characteristics of a population with Gaucher disease (GD) using multiparametric MRI and MR elastography (MRE) for evaluation of diffuse liver and spleen disease, which includes liver fat fraction, liver and spleen volume and iron deposition, and liver and spleen stiffness correlated with DS3 Severity Scoring System for Gaucher disease (GD-DS3). We prospectively evaluated 41 patients with type 1 Gaucher disease using a 3.0T MRI and MRE between January 2019 and February 2020. Clinical, laboratory, and imaging data was collected. Mann-Whitney, Kruskal-Wallis, and Spearman's correlation were applied to evaluate liver and spleen MRI and MRE, clinical and laboratory variables, and GD-DS3. ERT and SRT treatment groups were compared. Hepatomegaly was seen in 15% and splenomegaly in 42% of the population. Moderate and strong and correlations were found between liver and spleen iron overload (rho = 0.537; p = 0.002); between liver and spleen volume (rho = 0.692, p < 0.001) and between liver and spleen stiffness (rho = 0.453, p = 0.006). Moderate correlations were found between liver stiffness and GD-DS3 (rho = 0.559; p < 0.001) and between splenic volume and GD-DS3 (rho = 0.524; p = 0.001). The prevalence of hepatosplenomegaly, liver fibrosis, and liver iron overload in treated patients with GD is low, which may be related to the beneficial effect of treatment. Liver MRE and splenic volume correlate with severity score and may be biomarkers of disease severity.

Correlation between qualitative and semi-quantitative ultrasound assessment of diffuse fatty liver disease: A case-control study.

To study the relationship between qualitative and semi-quantitative assessment of diffuse liver steatosis in ultrasound. This was a case-control study, conducted in the Campus University Hospital Centre of Lome (Togo) over a 3-month period. It included 40 patients showing ultrasonographic signs of diffuse hepatic steatosis and 40 volunteers (healthy) whose echostructure and echogenicity of the hepatic parenchyma were normal. The B-mode sonographic grade of steatosis was compared with the hepatorenal echogenicity gradient and the ultrasound attenuation coefficient. The average body mass index in patients was 30.87 ± 4.65 kg/m2 versus 24.25 ± 4.30 kg/m2 in the healthy group (p < 0.00001). Hepatomegaly was observed in 57.5% of the patients versus 17.5% in the healthy group (p = 0.0005). The average hepatorenal echogenicity ratio was 1.18 ± 0.07 in patients versus 1.01 ± 0.03 in the healthy group (p < 0.00001). The average difference in hepatorenal echogenicity was 9.30 ± 3.41 dB in patients versus 1.52 ± 1.07 dB in the healthy group (p < 0.00001). The attenuation of ultrasound waves increased with the grade of steatosis, averaging 0.08 ± 0.23 dB/cm/MHz (ranging from -0.33 to 0.61 dB/cm/MHz) in patients versus -0.24 ± 0.21 (ranging from -0.69 to 0.19 dB/cm/MHz) in the healthy group (p < 0.00001). Despite the advancements in new ultrasound technologies today, qualitative methods continue to be effective for the detection of hepatic steatosis and could prove useful in monitoring the effectiveness of hepatic steatosis treatment.

Hospital readmissions after robotic hepatectomy for neoplastic disease: Analysis of risk factors, survival, and economical impact. A logistical regression and propensity score matched study

BackgroundAs the first comprehensive investigation into hospital readmissions following robotic hepatectomy for neoplastic disease, this study aims to fill a critical knowledge gap by evaluating risk factors associated with readmission and their impact on survival and the financial burden. MethodsThe study analyzed a database of robotic hepatectomy patients, comparing readmitted and non-readmitted individuals post-operatively using 1:1 propensity score matching. Statistical methods included Chi-square, Mann-Whitney U, T-test, binomial logistic regression, and Kaplan-Meier analysis. ResultsAmong 244 patients, 44 were readmitted within 90 days. Risk factors included hypertension (p ​= ​0.01), increased Child-Pugh score (p ​< ​0.01), and R1 margin status (p ​= ​0.05). Neoadjuvant chemotherapy correlated with lower readmission risk (p ​= ​0.045). Readmissions didn't significantly impact five-year survival (p ​= ​0.42) but increased fixed indirect hospital costs (p ​< ​0.01). ConclusionsReadmission post-robotic hepatectomy correlates with hypertension, higher Child-Pugh scores, and R1 margins. The use of neoadjuvant chemotherapy was associated with a lower admission rate due to less diffuse liver disease in these patients. While not affecting survival, readmissions elevate healthcare costs.

Improving Vessel Segmentation with Multi-Task Learning and Auxiliary Data Available Only During Model Training

Liver vessel segmentation in magnetic resonance imaging data is important for the computational analysis of vascular remodeling, associated with a wide spectrum of diffuse liver diseases. Existing approaches rely on contrast enhanced imaging data, but the necessary dedicated imaging sequences are not uniformly acquired. Images without contrast enhancement are acquired more frequently, but vessel segmentation is challenging, and requires large-scale annotated data. We propose a multi-task learning framework to segment vessels in liver MRI without contrast. It exploits auxiliary contrast enhanced MRI data available only during training to reduce the need for annotated training examples. Our approach draws on paired native and contrast enhanced data with and without vessel annotations for model training. Results show that auxiliary data improves the accuracy of vessel segmentation, even if they are not available during inference. The advantage is most pronounced if only few annotations are available for training, since the feature representation benefits from the shared task structure. A validation of this approach to augment a model for brain tumor segmentation confirms its benefits across different domains. An auxiliary informative imaging modality can augment expert annotations even if it is only available during training.

Non-alcoholic fatty liver disease and psoriasis: mechanisms of comorbidity and approaches to therapy

Psoriasis is a chronic immune-mediated skin disease of a multifactorial nature, characterized by accelerated proliferation of keratinocytes and impaired differentiation, an imbalance between pro-inflammatory and anti-inflammatory cytokines, with frequent involvement of the musculoskeletal system in the pathological process. The etiology of psoriasis is unknown, but several risk factors have been identified, including family history, smoking and obesity. The high prevalence of obesity, diseases of the cardiovascular system and digestive organs in patients with psoriasis allows us to consider it as an indicator of the patient’s metabolic disorders. In the structure of comorbidity of patients with psoriasis, special attention is drawn to non-alcoholic fatty liver disease (NAFLD), which occupies a leading position in the structure of the incidence of chronic diffuse liver diseases among the adult population in many countries of the world, including Russia. Patients with psoriasis are more often diagnosed with NAFLD, regardless of the presence of metabolic syndrome and other traditional risk factors. The presence of NAFLD is associated with more severe psoriasis and worse outcomes. On the other hand, a negative effect of psoriasis on the course of liver pathology has been noted. In this regard, it seems particularly relevant to study the etiological factors and pathogenetic links underlying this comorbidity, as potential targets for targeted therapy, which can improve the effectiveness of treatment for this cohort of patients. The purpose of this review publication is to summarize and systematize the available data on the prevalence of comorbidity of psoriasis and NAFLD in the population, the mechanisms of its formation and approaches to patient management.

Liver Magnetic Resonance Elastography: Focus on Methodology, Technique, and Feasibility.

Magnetic resonance elastography (MRE) is an imaging technique that combines low-frequency mechanical vibrations with magnetic resonance imaging to create visual maps and quantify liver parenchyma stiffness. As in recent years, diffuse liver diseases have become highly prevalent worldwide and could lead to a chronic condition with different stages of fibrosis. There is a strong necessity for a non-invasive, highly accurate, and standardised quantitative assessment to evaluate and manage patients with different stages of fibrosis from diagnosis to follow-up, as the actual reference standard for the diagnosis and staging of liver fibrosis is biopsy, an invasive method with possible peri-procedural complications and sampling errors. MRE could quantitatively evaluate liver stiffness, as it is a rapid and repeatable method with high specificity and sensitivity. MRE is based on the propagation of mechanical shear waves through the liver tissue that are directly proportional to the organ's stiffness, expressed in kilopascals (kPa). To obtain a valid assessment of the real hepatic stiffness values, it is mandatory to obtain a high-quality examination. To understand the pearls and pitfalls of MRE, in this review, we describe our experience after one year of performing MRE from indications and patient preparation to acquisition, quality control, and image analysis.

Liver transplantation program at the Burnasyan Federal Biophysical Center: experience in 500 procedures

To analyze the features and outcomes of 500 liver transplantations in adults over a 12-year period. The study included data on 500 liver transplantations between May 2010 and April 2023. We analyzed 483 adults who underwent transplantation and 438 candidates for this procedure. All data were obtained from local liver transplantation registry. Clinical outcomes were recorded as of June 1, 2023. Statistical analysis was performed using the Statistica 12 (StatSoft Inc., USA) and Jamovi version 2.3.21.0 software (Jamovi project). Among 438 patients in the waiting list between January 2012 and May 2023, liver transplantation was performed in 198 (45%) cases including 27 (6%) transplantations from living-related donors and 37 (8%) procedures in other centers. There were 109 (25%) deaths. The 1- and 3-year survival rates were 81% (95% CI 76-85%) and 50% (95% CI 42-59%), respectively. Organs from deceased donors (n=134, 27%) and living-related donors (n=366, 73%) were used for transplantations. Redo transplantations were necessary in 21 (4%) cases. The median age of recipients was 45 years (range 18-72), median MELD-Na score - 16 (range 6-43). The most common indications for transplantation were viral cirrhosis (37%), cholestatic liver disease (16%), and hepatocellular carcinoma (14%). Monotherapy with calcineurin inhibitors was performed in 39% of cases, combination of calcineurin inhibitors and glucocorticoids, antimetabolites or mTOR inhibitors - 52%, three-component schemes - 8% of cases. Annual, 5- and 7-year survival rates of recipients after primary transplantation were 87% (95% CI: 84-90%), 79% (95% CI: 75-83%) and 75% (95% CI: 70-80%), respectively. In case of liver transplantation from living-related donors, these values were 89% (95% CI: 86-92%), 84% (95% CI: 80-88%) and 80% (95% CI: 75-85%), after transplantation from deceased donors - 81% (95% CI: 74-88%), 66% (95% CI: 57-76%) and 58% (95% CI: 45-72%), respectively. Liver transplantation is highly effective for patients with diffuse and focal liver diseases. Living donors not only significantly improve availability of this technology, but also provide substantial advantages in outcomes compared to liver transplantation from deceased donors, reducing the likelihood of recipient mortality by 10% after one post-transplantation year and by more than 20% after five years.

Ultrasound Findings of Diffuse Liver Disease: Basic Steps to Understanding Sonographic Features

The ultrasound examination, capable of non-invasively detecting subtle changes in the liver's structure and form, can be extremely helpful. It is not only useful in identifying liver tumors but also in diagnosing and differentiating various liver diseases. Continuous monitoring with ultrasound is especially valuable in patients with chronic hepatitis B and C, as well as other chronic liver diseases, for understanding disease progression and early detection of hepatocellular carcinoma. It is also used in determining the degree of liver fibrosis. Therefore, our goal is to enhance diagnostic capabilities by describing basic ultrasound findings related to diffuse liver diseases.

An overview of ultrasound-derived radiomics and deep learning in liver.

Over the past few years, developments in artificial intelligence (AI), especially in radiomics and deep learning, have enabled the extraction of pathophysiology-related information from varied medical imaging and are progressively transforming medical practice. AI applications are extending into domains previously thought to be accessible only to human experts. Recent research has demonstrated that ultrasound-derived radiomics and deep learning represent an enticing opportunity to benefit preoperative evaluation and prognostic monitoring of diffuse and focal liver disease. This review summarizes the application of radiomics and deep learning in ultrasound liver imaging, including identifying focal liver lesions and staging of liver fibrosis, as well as the evaluation of pathobiological properties of malignant tumors and the assessment of recurrence and prognosis. Besides, we identify important hurdles that must be overcome while also discussing the challenges and opportunities of radiomics and deep learning in clinical applications.

INFORMATIVENESS OF TRANSIENT AND TWO-DIMENSIONAL SHEAR WAVE ELASTOGRAPHY IN ASSESSING OF LIVER STIFFNESS IN POST-COVID-19 AND CARDIOHEPATIC SYNDROMES

Ultrasound elastography of diffuse liver diseases allows to assess liver stiffness and predict the further course of the disease, determine the tactics of patient’s management for post-Covid and cardiohepatic syndrome. The purpose of the research – to study the diagnostic informativeness and evaluate the correlation between one-dimensional and two-dimensional shear wave elastography technologies with elastometry in assessing liver stiffness in patients with post-COVID and cardiohepatic syndromes. Materials and methods. A comparative analysis of the information content and correlation between the results of one-dimensional and two-dimensional shear wave elastography of the liver was carried out in 85 patients with post-COVID (N1; n = 30) and cardiohepatic (N2; n = 25) syndromes. The control group (N3; n = 30) consisted of patients without the new coronavirus infection COVID-19 and without any pathology of the liver and biliary system. In the control group, the study of liver parenchyma stiffness using shear wave elastography was carried out by lobes and segments. Standard variation statistics algorithms were used, taking into account the type of data distribution in the statistical analysis. Quantitative indicators with a normal distribution were described using arithmetic means (M) and standard deviations (SD), boundaries of the 95% confidence interval (95% CI). In the absence of a normal distribution, quantitative data were described using the median (Me) and lower and upper quartiles (Q1–Q3). Research results. The stiffness values (Emean) in the projection of segments VI, VII had larger values (p = 0.02) when compared with other segments. We obtained the following Emean values in transient elastography: in the group of patients with post-COVID syndrome (N1) – 10.02 kPa; in the group of patients with chronic heart failure (N2) – 14.09 kPa, which turned out to be significantly higher than the stiffness of the liver parenchyma among healthy individuals, where the Emean value was 4.90 kPa (p = 0.05). With shear wave elastography, the results were also higher in the group of patients with chronic heart failure (N2), where Emean was 20.90 kPa, compared to the group of patients with post-COVID syndrome (N1) – 11.86 kPa. Conclusions. The results of shear wave elastography were successful in 100% of cases, the results of transient elastography in 84.6% of cases. Correlation analysis of connections in a group of patients with chronic heart failure according to TE and SWE showed a weak positive direct linear correlation. A positive direct linear correlation of medium strength was obtained in assessing the correlation in the group of patients with post-COVID syndrome.

Assessment of the nutritional state of patients with chronic diffuse liver diseases

Chronic liver diseases present a serious problem of modern medicine. Quite often, patients with liver diseases suffer from a violation of the normal nutritional state. such as malnutrition against the background of deficiency or increased body weight, which can develop latently in the early stages of the liver pathology and lead to protein-energy malnutrition, the development of sarcopenia and its complications. Aim. Evaluation of the nutritional status of patients with chronic diffuse liver diseases using anthropometric and biochemical parameters. Materials and methods. There were examined 282 patients, men n=138(49%), women n=144(51%) with liver pathology, whom were divided into groups: 1 gr - with chronic hepatitis n=75 (27. 4%), 2 gr - with chronic fatty non-alcoholic liver disease n=96 (34. 2%), and 3 gr - with liver cirrhosis of various etiology n=111 (39. 4%). The average age is 54. 23. Anthropometric studies were carried out (chest circumference, waist circumference, circumference of the middle part of the shoulder, thigh circumference), body mass index was calculated. In all patients, we studied the indicators of protein metabolism - total protein and albumin levels in blood serum. Results. The study revealed the presenceof abdominal fat in all patients, characteristic of obesity sarcopenia and a decrease in protein metabolism: total protein and albumin in patients with liver cirrhosis. Conclusions. All patients have an android type of adipose tissue distribution and are at high risk of developing comorbid cardiovascular and endocrine dysfunction.

Management of gallstone disease and chronic liver diseases during the COVID-19 outbreak in Ukraine: an ecological study

PurposeThe purpose of this paper is to estimate the possible impact of the COVID-19 pandemic on the hospitalization and hospital mortality of the patients with gallstone disease and chronic liver diseases (CLD) in the worst pandemic period in Ukraine.Design/methodology/approachA retrospective comparative analysis of annual reports data of all economy subjects, which conducted economic activity in medical practice for 2019 and 2021. Data was accepted from the Ministry of Health of Ukraine, the National Security and Defense Council of Ukraine (NSDC) and the State Statistics Service of Ukraine (SSSU).FindingsThe total hospitalization rates for diffuse liver disease and cholelithiasis significantly decreased during the peak of the COVID-19 pandemic in Ukraine, compared to the values of 2019. At the same time, the rates of in-hospital mortality for these diseases have significantly grown. Also, various proportions of similar trends were described in other countries during the first wave of the pandemic.Originality/valueThis paper highlights the fact that regulatory restrictions and the fear of the population of referring to healthcare facilities considering the high risk of getting an infection had significant disruption to medical care for patients with gallstone disease and CLD. Improving the management of medical resources and strengthening all kinds of institutions in the healthcare system must be thought about if similar challenges appear in the future.

Ultrasonic Sound Speed Estimation for Liver Fat Quantification: A Review by the AIUM-RSNA QIBA Pulse-Echo Quantitative Ultrasound Initiative.

Non-alcoholic fatty liver disease (NAFLD) is a significant cause of diffuse liver disease, morbidity and mortality worldwide. Early and accurate diagnosis of NALFD is critical to identify patients at risk of disease progression. Liver biopsy is the current gold standard for diagnosis and prognosis. However, a non-invasive diagnostic tool is desired because of the high cost and risk of complications of tissue sampling. Medical ultrasound is a safe, inexpensive and widely available imaging tool for diagnosing NAFLD. Emerging sonographic tools to quantitatively estimate hepatic fat fraction, such as tissue sound speed estimation, are likely to improve diagnostic accuracy, precision and reproducibility compared with existing qualitative and semi-quantitative techniques. Various pulse-echo ultrasound speed of sound estimation methodologies have been investigated, and some have been recently commercialized. We review state-of-the-art in vivo speed of sound estimation techniques, including their advantages, limitations, technical sources of variability, biological confounders and existing commercial implementations. We report the expected range of hepatic speed of sound as a function of liver steatosis and fibrosis that may be encountered in clinical practice. Ongoing efforts seek to quantify sound speed measurement accuracy and precision to inform threshold development around meaningful differences in fat fraction and between sequential measurements.

Real-Time Shear Wave Elastography for Determining the Ideal Site of Liver Biopsy in Diffuse Liver Disease.

Objectives The objective of the study was to identify accurate site of liver biopsy under ultrasound and elastography guidance and compare the shear wave elastography (SWE) and transient elastography (TE) diagnostic accuracy with histopathological correlation. Methods This was a prospective single-center study where patients scheduled for nonfocal liver biopsy were divided into two groups (group U: ultrasound; group E elastography) by sequential nonrandom selection of patients. Elastography was performed before the biopsy and biopsies from the maximum stiffness segment were taken. Results There was no significant difference of intersegmental liver stiffness with mean velocity; however, biopsy segment velocities show significant difference with mean liver stiffness suggestive of heterogenous distribution of fibrosis. The rho ( r ; Spearman's correlation) value between biopsy segments and mean velocities shows excellent correlation. The diagnostic performance of TE was good for fibrosis stages F2, F3, and F4, while SWE was fair for the diagnosis of fibrosis stages F1 and F2 and fairly equal for the diagnosis stages F2 and F3. Area under the curve (AUC) values in differentiating mild (F1) or no fibrosis from significant fibrosis (≥F2) were 95.5 with cutoff value of at least 1.94 m/s. Conclusions The diagnostic performance of SWE is comparable with TE in liver fibrosis staging and monitoring. Fibrosis is heterogeneously distributed in different segments of the right lobe liver. Therefore, elastography at the time of biopsy may help in defining the accurate site for biopsy and improve histopathological yield in detecting liver fibrosis in patients with chronic liver disease. Advances in Knowledge Elastography-guided biopsy is helpful to determine the ideal site of biopsy.