Body mass index and liver stiffness affect accuracy of ultrasonography in detecting steatosis in patients with chronic hepatitis C virus genotype 1 infection

Altered probe pressure and body position increase diagnostic accuracy for men and women in detecting hepatic steatosis using quantitative ultrasound

OBJECTIVES

To evaluate the diagnostic performance of ultrasound guided attenuation parameter (UGAP) for evaluating liver fat content with different probe forces and body positions, in relation to sex, and compared with proton density fat fraction (PDFF).

METHODS

We prospectively enrolled a metabolic dysfunction-associated steatotic liver disease (MASLD) cohort that underwent UGAP and PDFF in the autumn of 2022. Mean UGAP values were obtained in supine and 30° left decubitus body position with normal 4 N and increased 30 N probe force. The diagnostic performance was evaluated by the area under the receiver operating characteristic curve (AUC).

RESULTS

Among 60 individuals (mean age 52.9 years, SD 12.9; 30 men), we found the best diagnostic performance with increased probe force in 30° left decubitus position (AUC 0.90; 95% CI 0.82-0.98) with a cut-off of 0.58 dB/cm/MHz. For men, the best performance was in supine (AUC 0.91; 95% CI 0.81-1.00) with a cut-off of 0.60 dB/cm/MHz, and for women, 30° left decubitus position (AUC 0.93; 95% CI 0.83-1.00), with a cut-off 0.56 dB/cm/MHz, and increased 30 N probe force for both genders. No difference was in the mean UGAP value when altering body position. UGAP showed good to excellent intra-reproducibility (Intra-class correlation 0.872; 95% CI 0.794-0.921).

CONCLUSION

UGAP provides excellent diagnostic performance to detect liver fat content in metabolic dysfunction-associated steatotic liver diseases, with good to excellent intra-reproducibility. Regardless of sex, the highest diagnostic accuracy is achieved with increased probe force with men in supine and women in 30° left decubitus position, yielding different cut-offs.

CLINICAL RELEVANCE STATEMENT

The ultrasound method ultrasound-guided attenuation parameter shows excellent diagnostic accuracy and performs with good to excellent reproducibility. There is a possibility to alter body position and increase probe pressure, and different performances for men and women should be considered for the highest accuracy.

KEY POINTS

• There is a possibility to alter body position when performing the ultrasound method ultrasound-guided attenuation parameter. • Increase probe pressure for the highest accuracy. • Different performances for men and women should be considered.

Ultrasonographic Assessment of Tissue Stiffness: Recent Progress in Transient Elastography and Shear Wave Elastography in the Liver and Various Organs

Ultrasonography is a noninvasive and widely accessible modality in clinical practice. Recently, ultrasonography has been used to evaluate tissue stiffness; the two representative techniques are transient elastography (FibroScan®) and shear wave elastography. These modalities are now generally used for the assessment of liver fibrosis, the prediction of hepatocarcinogenesis, and determining prognosis. In addition, shear wave elastography is available, not only for the liver but also for various other organs, including the breast and brain. In the breast and brain, shear wave elastography distinguishes malignant lesions from benign ones. Moreover, shear wave elastography can be useful for differentiating between ischemic and hemorrhagic strokes. This review summarizes the recent progress in transient elastography and shear wave elastography of the liver and introduces the advantages of ultrasonographic assessment of tissue stiffness in various organs, including the breast, brain, kidney, heart, thyroid, pancreas, muscle, and bone.

Quantification of Liver Fat Content with Ultrasound: A WFUMB Position Paper

New ultrasound methods that can be used to quantitatively assess liver fat content have recently been developed. These quantitative ultrasound (QUS) methods are based on the analysis of radiofrequency echoes detected by the transducer, allowing calculation of parameters for quantifying the fat in the liver. In this position paper, after a section dedicated to the importance of quantifying liver steatosis in patients with non-alcoholic fatty liver disease and another section dedicated to the assessment of liver fat with magnetic resonance, the current clinical studies performed using QUS are summarized. These new methods include spectral-based techniques and techniques based on envelope statistics. The spectral-based techniques that have been used in clinical studies are those estimating the attenuation coefficient and those estimating the backscatter coefficient. Clinical studies that have used tools based on the envelope statistics of the backscattered ultrasound are those performed by using the acoustic structure quantification or other parameters derived from it, such as the normalized local variance, and that performed by estimating the speed of sound. Experts' opinions are reported.

Conventional ultrasound for diagnosis of hepatic steatosis is better than believed

BACKGROUND

Hepatic steatosis is a condition frequently encountered in clinical practice, with potential progression towards fibrosis, cirrhosis, and hepatocellular carcinoma. Detection and staging of hepatic steatosis are of most importance in nonalcoholic fatty liver disease (NAFLD), a disease with a high prevalence of more than 1 billion individuals affected. Ultrasound (US) is one of the most used noninvasive imaging techniques used in the diagnosis of hepatic steatosis. Detection of hepatic steatosis with US relies on several conventional US parameters, which will be described. US is the first-choice imaging in adults at risk for hepatic steatosis. The use of some scoring systems may add additional accuracy especially in assessing the severity of hepatic steatosis.

SUMMARY

In the presented paper, we discuss screening and risk stratification, ultrasound features for diagnosing hepatic steatosis, B-mode criteria, focal fatty patterns and Doppler features of the hepatic vessels, and the value of the different US signs for the diagnosis of liver steatosis including classifying the severity of steatosis using different US scores. Limitations of conventional B-mode and Doppler features in the evaluation of hepatic steatosis are also discussed, including those in grading and assessing the complications of steatosis, namely fibrosis and nonalcoholic steatohepatitis.

KEY MESSAGES

Ultrasound is the first-line imaging examination for the screening and follow-up of patients with liver steatosis. The use of some scoring systems may add additional accuracy in assessing the severity of steatosis. Conventional B-mode and Doppler ultrasound have limitations in grading and assessing the complications of steatosis.

How intrahepatic cholestasis affects liver stiffness in patients with chronic hepatitis B: a study of 1197 patients with liver biopsy

OBJECTIVES

To evaluate the impact of intrahepatic cholestasis on liver fibrosis staging using liver stiffness measurements (LSM).

METHODS

Between July 2011 and September 2016, a total of 1197 patients with chronic hepatitis B (CHB) infection were enrolled to collect clinical, biological, 2D shear wave elastography (SWE), and histological (METAVIR scoring system) data. LSM was compared in patients with normal total bilirubin (TB) versus abnormal TB for each group of fibrosis stage, alanine aminotransferase (ALT) levels, and inflammation grade. Logistic regression and ROC analyses were performed to assess the benefit of adding TB and to LSM for fibrosis staging.

RESULTS

Nine hundred and seventy-three patients were analyzed. Within the same fibrosis stage, LSMs showed significantly higher value in patients with abnormal TB than those with normal TB. Increased LSM for abnormal TB was generally found within different sub-groups of patients (≤ F2 or ≥ F3; ALT < 2 × upper limit of normal (ULN) or ALT ≥ 2 × ULN; METAVIR activity grade ≤ 1 or ≥ 2). Patients with abnormal TB level showed higher optimal cutoff values: 10.46 kPa for ≥ F2, 10.94 kPa for ≥ F3, and 15.88 kPa for F4, than those with normal TB (7.62 kPa, 8.26 kPa, and 11.01 kPa, respectively). LSM assessed fibrosis stage (≥ F2, ≥ F3, F4) showed higher false positive rate in patients with abnormal TB level (44.6%, 45.1%, 39.6%) than those with normal TB (20.7%, 17.1%, 14.4%). However, the area under the ROC curve did not change appreciably when adding TB to LSM for fibrosis stage.

CONCLUSION

Intrahepatic cholestasis showed slight effect on LSM in patients with CHB, also leading to overestimation of liver fibrosis stages. But adding TB level to LSM did not improve the overall diagnostic performance of liver fibrosis stage.

KEY POINTS

• Intrahepatic cholestasis showed slight effect on liver stiffness measurements (LSMs) in chronic HBV patients. • Patients with abnormal total bilirubin (TB) level showed higher optimal cutoff values and false positive rate. • When taking into account intrahepatic cholestasis, the diagnostic performance of LSM for liver fibrosis staging in patients with chronic HBV infection will not improve.

Ultrasonographic fatty liver indicator detects mild steatosis and correlates with metabolic/histological parameters in various liver diseases

BACKGROUND AND AIMS

Fatty liver is a common feature of different types of liver diseases. The sensitivity and specificity of ultrasonography for diagnosing fatty liver are variable. A semi-quantitative ultrasound score, i.e., the ultrasonographic fatty liver indicator (US-FLI), is closely associated with metabolic/histological variables in patients with nonalcoholic fatty liver disease (NAFLD). The main aims of this study were to assess the diagnostic performance of US-FLI in detecting varying degrees of histological steatosis, and to examine the association of US-FLI with metabolic/histological parameters in 352 biopsied patients with various chronic liver diseases (173 with hepatitis C [HCV], 23 with hepatitis B [HBV], 123 with NAFLD and 33 with other etiologies).

RESULTS

US-FLI accurately detected mild steatosis (minimum amount 10% on histology) with a cut-off value ≥2 (sensitivity 90.1%, specificity 90%), moderate steatosis (≥30%) with a cut-off value ≥3 (sensitivity 86.4%, specificity 92.5%) and severe steatosis (>66%) with a cut-off value ≥5 (sensitivity 88.5%, specificity 87%). US-FLI was correlated with steatosis percentage in each liver disease group as well as with lobular inflammation, ballooning, portal fibrosis, grading and staging in patients with NAFLD or HCV. US-FLI was also correlated with waist circumference, body mass index and insulin resistance both in the whole sample and in each liver disease group.

CONCLUSIONS

US-FLI accurately identifies histological severity and is correlated with metabolic parameters in patients with various steatogenic liver diseases. US-FLI is an easy and versatile tool for the screening of steatosis and the metabolic health of these patients.

The severity of steatosis influences liver stiffness measurement in patients with nonalcoholic fatty liver disease

In nonalcoholic fatty liver disease, the influence of severity of steatosis on liver stiffness measurement (LSM) is poorly studied and still debated. We assessed the impact of steatosis severity and its ultrasonographic (US) sign, severe bright liver echo pattern, on LSM values and on transient elastography accuracy for the diagnosis of liver fibrosis in a cohort of consecutive patients with nonalcoholic fatty liver disease. Patients (n = 253) were assessed by clinical, US, and histological (Kleiner score) features. Transient elastography was performed using the M probe. Among patients with low amounts of fibrosis (F0-F1 and F0-F2), median LSM values, expressed in kilopascals, were significantly higher in subjects with severe steatosis (≥66% at liver biopsy) compared to those without (F0-F1 6.9 versus 5.8, P = 0.04; F0-F2 7.4 versus 6.0, P = 0.001) as well as in patients with severe bright liver echo pattern on US compared to their counterparts (F0-F1 7.3 versus 5.6, P = 0.001; F0-F2 7.6 versus 6.0, P < 0.001). In subjects without significant fibrosis (F0-F1) and without severe fibrosis (F0-F2), a higher rate of false-positive LSM results was observed in patients with steatosis ≥66% compared to those without (F0-F1 23.6% versus 14.9%, F0-F2 33.3% versus 13.2%) and in patients with severe bright liver echo pattern on US (F0-F1 22.2% versus 15.4%, F0-F2 28.8% versus 15.6%) compared to their counterparts.

CONCLUSIONS

In patients with nonalcoholic fatty liver disease, the presence of severe steatosis, detected by histology or by US, should always be taken into account in order to avoid overestimations of liver fibrosis assessed by transient elastography.

Steatosis affects the performance of liver stiffness measurement for fibrosis assessment in patients with genotype 1 chronic hepatitis C

BACKGROUND & AIMS

In Chronic Hepatitis C (CHC), the influence of steatosis on liver stiffness measurement (LSM) is still debated. We assessed the impact of steatosis and its ultrasonographical sign - bright liver echo pattern (BLEP) - on LSM values and on transient elastography (TE) accuracy for the diagnosis of liver fibrosis, in a cohort of consecutive patients with Genotype 1 (G1) CHC.

METHODS

Patients (n=618) were assessed by clinical, ultrasonographic and histological (Scheuer score) features. TE was performed using the M probe.

RESULTS

Male gender (p=0.04), steatosis as continuous variable (p<0.001), severity of necroinflammation (p=0.02) and stage of fibrosis (p<0.001) were associated with LSM by multivariate linear regression analysis. Among patients within the same fibrosis stages (F0-F2 and F3-F4; F0-F3 and F4), mean LSM values, expressed in kPa, were significantly higher in subjects with moderate-severe steatosis (⩾20% at liver biopsy) compared with those without, as well as in patients with BLEP on US compared with their counterpart. In subjects without severe fibrosis (F0-F2) and without cirrhosis (F0-F3), a higher rate of false-positive LSM results was observed in patients with steatosis ⩾20% compared with those without (F0-F2: 35.3% vs. 17.9%; F0-F3: 38.9% vs. 16.6%), and in patients with BLEP on US (F0-F2: 28.0% vs. 18.3%; F0-F3: 29.7% vs. 17.8%) compared with their counterpart.

CONCLUSIONS

In patients with G1 CHC, the presence of moderate-severe steatosis, detected by histology or by US, should always be taken into account in order to avoid overestimations of liver fibrosis assessed by TE.