Transient elastography (TE), shear wave elastography, and/or magnetic resonance elastography (MRE), each providing liver stiffness measurement (LSM), are the most studied imaging-based noninvasive liver disease assessment (NILDA) techniques. To support the American Association for the Study of Liver Diseases guidelines on NILDA, we summarized the evidence on the accuracy of these LSM methods to stage liver fibrosis (F).

A comprehensive search for studies assessing LSM by TE, shear wave elastography, or MRE for the identification of significant fibrosis (F2-4), advanced fibrosis (F3-4), or cirrhosis (F4), using histopathology as the standard of reference by liver disease etiology in adults or children from inception to April 2022 was performed. We excluded studies with <50 patients with a single disease entity and mixed liver disease etiologies (with the exception of HCV/HIV coinfection). Out of 9447 studies, 240 with 61,193 patients were included in this systematic review. In adults, sensitivities for the identification of F2-4 ranged from 51% to 95%, for F3-4 from 70% to 100%, and for F4 from 60% to 100% across all techniques/diseases, whereas specificities ranged from 36% to 100%, 74% to 100%, and 67% to 99%, respectively. The largest body of evidence available was for TE; MRE appeared to be the most accurate method. Imaging-based NILDA outperformed blood-based NILDA in most comparisons, particularly for the identification of F3-4/F4. In the pediatric population, imaging-based NILDA is likely as accurate as in adults.

LSM from TE, shear wave elastography, and MRE shows acceptable to outstanding accuracy for the detection of liver fibrosis across various liver disease etiologies. Accuracy increased from F2-4 to F3-4 and was the highest for F4. Further research is needed to better standardize the use of imaging-based NILDA, particularly in pediatric liver diseases.

Liver stiffness measurement (LSM) and spleen stiffness measurement (SSM) have been shown to be useful tools for assessing the risk of fibrosis and portal hypertension, respectively. However, data on the accuracy of LSM and SSM measured by point-shear wave elastography (pSWE) in patients affected by primary sclerosing cholangitis (PSC) are still lacking. Thus, we aimed to prospectively assess their performance in a cohort of patients with PSC.

We determined the correlation between LSM assessed by a pSWE technique (ElastPQ) and by FibroScan-transient elastography (F-TE). Furthermore, we used receiver-operating characteristic curves and area under the curves (AUROC) to evaluate the performance of LSM by ElastPQ for the staging of fibrosis, using F-TE as a reference standard, and the performance of LSM and SSM by ElastPQ in predicting the presence of oesophageal varices (OVs).

One hundred and fifty-two patients with PSC (93 males [61.2%], mean age 46 ± 16 years) were prospectively recruited. ElastPQ and F-TE LSMs were available for all patients, while ElastPQ SSM was available in 109 (72%) patients of whom 35 underwent upper gastrointestinal endoscopy within 1 year of the ultrasound assessment. ElastPQ LSM showed an excellent correlation with F-TE (p <0.001, Spearman's 0.93; Lin's 0.86) and a good diagnostic accuracy for fibrosis staging along all stages of liver fibrosis (AUROCs 0.96, 0.97, 0.97 and 0.99 for fibrosis stages F≥1, F≥2, F≥3 and F=4, respectively), using F-TE as a surrogate of histological fibrosis. ElastPQ SSM showed a good diagnostic performance in predicting the presence of OVs at endoscopy.

LSM and SSM by ElastPQ can be used as accurate tools for liver fibrosis risk assessment and fibrosis staging, as well as for predicting the presence of OVs in the work-up of patients with PSC.

Liver and spleen stiffness measurement (LSM and SSM, respectively) by ElastPQ point-shear wave elastography in patients with primary sclerosing cholangitis represent reliable and reproducible tools for non-invasively staging the severity of liver disease and stratifying patients according to their risk of developing liver-related outcomes. In particular, LSM shows good accuracy for staging liver fibrosis and therefore detecting those patients at high risk of having compensated advanced chronic liver disease who require close monitoring. SSM seems to be promising to detect the risk of portal hypertension and therefore of oesophageal varices, enabling the triaging of patients who really need to undergo a screening endoscopy.

To evaluate the role of elastography point quantification (ElastPQ) for the quantitative assessment of stiffness in the fatty liver disease in mental disorder patients and to provide a noninvasive detection method for non-alcoholic fatty liver (NAFLD) caused by atypical antipsychotics drugs (AAPDs).

A total number of 168 mental disorder patients treated with AAPDs and 58 healthy volunteers were enrolled in this study. All the subjects underwent ultrasound and ElastPQ tests. The basic data of the patients were analyzed.

BMI, liver function, and the value of ElastPQ were considerably higher in the patient group than that in the healthy volunteers. The values of liver stiffness obtained by ElastPQ were increased gradually from 3.48(3.14-3.81) kPa in the normal liver to 8.15(6.44-9.88) in the severe fatty liver. The receiver operating characteristic (ROC) for the diagnosis of fatty liver with ElastPQ were 0.85, 0.79, 0.80, and 0.87 for the diagnosis of normal, mild, moderate, and severe steatosis, respectively, with a sensitive/specificity of 79%/76.4%, 85.7%/78.3%, 86.2%/73%, and 81.3%/82.1%, correspondingly. Moreover, ElastPQ in the olanzapine group was higher than those in the risperidone and aripiprazole groups (5.11(3.83-5.61) kPa vs 4.35(3.63-4.98) kPa, P < 0.05; 5.11(3.83-5.61) kPa vs 4.79(4.18-5.24) kPa, P < 0.05). After one-year treatment, the value of ElastPQ was 4.43(3.85-5.22) kPa, but it was 5.81(5.09-7.33) kPa in patients treated for more than three years. This value increased with treatment prolongation (P < 0.05).

ElastPQ is a real-time, quantitative method for assessing the stiffness of NAFLD. The liver stiffness value could be varied in the different stages of fatty liver. Olanzapine has a considerable influence on liver stiffness. The long-term use of AAPDs can increase the stiffness value of fatty liver.

The aim of the study was to demonstrate the liver stiffness (LS) change in chronic hepatitis C (CHC) patients obtained by elastography point quantification technique in before and after antiviral treatment (AVT).

This prospective study included 84 patients diagnosed with CHC who had not previously received treatment for CHC and who had an indication for using direct-acting AVT. Necessary measurements were recorded with noninvasive liver fibrosis (LF) examinations. Posttreatment control of patients was carried out (ombitasvir + paritaprevir + ritonavir) + 3 months after the start of treatment for those treated with dasabuvir and 6 months after the start of treatment for patients treated with sofosbuvir + ribavirin. Liver stiffness changed after AVT is accepted as (Δ-LS), LS before AVT-LS after AVT.

Basal LS was found to decrease significantly after AVT (8.00 ± 2.56 kPa vs 6.95 ± 2.86 kPa, P < 0.05). Similar aspartate aminotransferase-to-platelet ratio index and platelet number fibrosis 4 indices were observed before and after AVT (P > 0.05). It was observed that Δ-LS value after AVT was lower in patients with Child-Pugh class A cirrhosis than patients without cirrhosis (P < 0.05). In the comparison between Δ-LS value after AVT and LF score determined by liver biopsy, it was seen that the greatest Δ-LS value was in patients with fibrosis score of 3. An independent relationship was found between Δ-LS after AVT and LF score determined by biopsy (P < 0.05).

The LS value determined by the elastography point quantification technique is more effective than other noninvasive laboratory methods in demonstrating the CHC treatment response in clinical practice.

This retrospective study aimed to compare the discriminative performance between magnetic resonance elastography (MRE) and biological markers in detecting liver fibrosis and in predicting postoperative ascites (PA).

We enrolled 77 patients consecutively who underwent hepatectomy between March 2017 and June 2019. Liver fibrosis was histopathologically graded using the METAVIR scoring system as reference. Discriminative performance of non-invasive assessments in detecting different stages of liver fibrosis and predicting PA was evaluated by receiver-operator curve analysis.

The concordance indices (C-indices) for MRE and biological markers for detecting significant fibrosis (≥F2) and cirrhosis (F4) were: MRE, 0.84 and 0.86; Wisteria floribunda agglutinin + Mac-2 binding protein (WM2BP), 0.63 and 0.71; Hyaluronic acid (HA), 0.72 and 0.75; 7 S-type 4 collagen (T4C), 0.61 and 0.66; APRI, 0.76 and 0.83; and Fib-4, 0.75 and 0.76. Univariable logistic analysis for predicting PA showed that C-indices were 0.751 (p = 0.007), 0.798 (p = 0.106), 0.771 (p = 0.050), 0.674 (p = 0.855), 0.655 (p = 0.263), and 0.560 (p = 0.640) for MRE, WM2BP, Fib-4, HA, APRI, and T4C, respectively.

MRE has a higher diagnostic performance than biological markers in detecting the stages of liver fibrosis and is a predictor for PA after hepatectomy.

Direct-acting antivirals (DAA) have replaced interferon (IFN)-based therapies for hepatitis C virus. In this retrospective clinical study, we examined differences in histopathologic features in paired liver biopsies collected from the same patient before and after DAA and correlated these findings with clinical outcome. Biopsies (n = 19) were evaluated by quantitative imaging analysis to measure steatosis and fibrosis. Most patients had decreased steatosis in their post-treatment, follow-up biopsies. However, one patient had a striking increase in steatosis (from 0.86 to 6.32%) and later developed decompensated cirrhosis and hepatocellular carcinoma (HCC). This patient had a marked increase in fibrosis between biopsies, with a CPA of 6.74 to 32.02. Another patient, who already had bridging fibrosis at the time of her pre-treatment biopsy, developed cholangiocarcinoma after DAA. Even though the overall inflammatory activity in the post-treatment biopsies significantly decreased after treatment, 60% of patients had persistent portal lymphocytic inflammation. In summary, DAAs decreased steatosis and hepatic inflammation in most patients, although some may have persistence of lymphocytic portal inflammation. Patients known to have advanced fibrosis at treatment initiation and who have other risk factors for ongoing liver injury, such as steatosis, should be followed closely for the development of adverse outcomes, such as portal hypertension and primary liver cancers.

The severity of liver fibrosis can be assessed noninvasively today by liver stiffness measurements. Vibration-controlled transient elastography, shear wave elastography or magnetic resonance elastography are techniques increasingly used for this purpose.

This article presents the recent advances in the use of new techniques for liver fibrosis assessment in chronic hepatitis C: the correlation between liver stiffness values and liver fibrosis estimated by liver biopsies, the prognosis role of liver stiffness values, their usefulness in monitoring the treatment response, in assessing the severity of portal hypertension and in estimating the presence of esophageal varices. Scientific articles from January 2017 to January 2018 were searched in PubMed and PubMed Central databases, using the terms "liver stiffness" and "hepatitis C".

The median liver stiffness values measured with different techniques are not identical, so that FibroScan thresholds cannot be used on any other elastographic machine. The higher the liver's stiffness measurement, the higher the liver-related events in patients with chronic hepatitis C. A liver stiffness measurement over 17 kPa could be an independent predictor for the presence of esophageal varices as well as a spleen with a longitudinal span ≥ 15 cm for patients with a value of liver stiffness < 17 kPa. A progressive and persistent decrease in liver stiffness is dependent on sustained virological response achievement. The lack of liver stiffness decrease has been associated with relapsers and a low value of liver stiffness at baseline.

Liver stiffness provides clues about the severity and evolution of liver disease.

To systematically review studies about the diagnostic accuracy of magnetic resonance imaging proton density fat fraction (MRI-PDFF) in the classification of hepatic steatosis grade in patients with non-alcoholic fatty liver disease (NAFLD).

Areas under the summary receiver operating characteristic curves (AUROC), sensitivity, specificity, overall diagnostic odds ratio (DOR), diagnostic score, positive likelihood ratio (+LR), and negative likelihood ratio (-LR) for MRI-PDFF in classification of steatosis grades 0 vs. 1-3, 0-1 vs. 2-3, and 0-2 vs. 3 were compared and analyzed.

A total of 6 studies were included in this meta-analysis (n = 635). The summary AUROC values of MRI-PDFF for classifying steatosis grades 0 vs. 1-3, 0-1 vs. 2-3, and 0-2 vs. 3 were 0.98, 0.91, and 0.90, respectively. Pooled sensitivity and specificity of MRI-PDFF for classifying steatosis grades 0 vs. 1-3, 0-1 vs. 2-3, and 0-2 vs. 3 were 0.93 and 0.94, 0.74 and 0.90, and 0.74 and 0.87, respectively. Summary +LR and -LR of MRI-PDFF for classifying steatosis grades 0 vs. 1-3, 0-1 vs. 2-3, and 0-2 vs. 3 were 16.21 (95%CI, 4.72-55.67) and 0.08 (95%CI, 0.04-0.15), 7.19 (95%CI, 5.04-10.26) and 0.29 (95%CI, 0.22-0.38), and 5.89 (95%CI, 4.27-8.13) and 0.29 (95%CI, 0.21-0.41), respectively.

Our meta-analysis suggests that MRI-PDFF has excellent diagnostic value for assessment of hepatic fat content and classification of histologic steatosis in patients with NAFLD.

• MRI-PDFF has significant diagnostic value for hepatic steatosis in patients with NAFLD. • MRI-PDFF may be used to classify grade of hepatic steatosis with high sensitivity and specificity.

Elastography point quantification (ElastPQ) is a non-invasive method for assessing liver fibrosis based on liver stiffness. We evaluated the accuracy of ElastPQ for the staging of liver fibrosis in patients with chronic liver disease (CLD) compared with aspartate transaminase to platelet ratio index, fibrosis-4 index, and transient elastography (TE), using liver biopsy as reference standard.

We performed a retrospective study of 406 patients with CLD of any etiology who underwent liver biopsy analysis from September 2012 through June 2017 at a clinic in Bologna, Italy. We obtained liver stiffness measurements, made by ElastPQ and TE, for 361 patients. Liver fibrosis stage was assessed by the METAVIR scoring system. Areas under the receiver operating characteristic curve (AUROC) were used to assess the diagnostic performance of ElastPQ.

ElastPQ values correlated with histologic detection of fibrosis (r = 0.718; P < .001). The AUROC values were 0.856 for detection of significant fibrosis (F≥2), 0.951 for advanced fibrosis (F≥3), and 0.965 for cirrhosis. The best cut-off values identified for classifying patients with F≥2, F≥3, or cirrhosis were 6.0 kPa, 6.2 kPa, and 9.5 kPa, respectively: these were lower than those for TE. Comparison of ElastPQ with TE data resulted in superimposable diagnostic accuracy of both methods for each stage of liver fibrosis. Both elastography techniques performed better than aspartate transaminase to platelet ratio index or fibrosis-4 index scores (P < .05 for all AUROC comparisons).

ElastPQ has good to excellent performance for the non-invasive staging of liver fibrosis in patients with CLD. ElastPQ identified patients with fibrosis or cirrhosis with levels of accuracy that were not inferior to those of TE, and outperformed serum fibrosis indexes in identifying each stage of liver fibrosis.

It has been postulated that in the liver, applying increased probe pressure during ultrasound-based shear wave elastography (SWE) might lead to a false increase in the SWE result. We aimed to determine the influence of increased intercostal probe pressure when performing SWE of the liver. We also investigated the number of measurements required to achieve technically successful and reliable SWE examinations. This prospective, clinical study included 112 patients and 2240 SWE measurements of the liver. We applied probe pressure intercostally, to reduce the skin-to-liver capsule distance (SCD), which could stabilize the SWE signal and thus increase the number of technically successful measurements. We performed 10 measurements with maximum probe pressure and 10 with normal pressure in each patient. Thus, two analysis groups were compared for differences. Compared with normal pressure, maximum probe pressure significantly reduced the SCD (p < 0.001) and significantly increased the number of technically successful measurements from 981 to 1098, respectively (p < 0.001). The SWE results with normal and maximum probe pressure were 5.96 kPa (interquartile range: 2.41) and 5.45 kPa (interquartile range: 1.96), respectively (p < 0.001). In obese patients, a large SCD poses a diagnostic challenge for ultrasound SWE. We found that maximum intercostal probe pressure could reduce the SCD and increase the number of technically successful measurements, without falsely increasing the SWE result. Only three measurements were required to achieve technically successful and reliable SWE examinations.

Assessment of liver stiffness provides important diagnostic and prognostic information in patients with chronic liver disease.

To investigate whether the use of quality criteria (i) improves the concordance between transient elastography (TE) and a novel point shear wave elastography technique (ElastPQ®) and (ii) impacts on the performance of ElastPQ® for liver fibrosis staging using TE as the reference standard.

In this multicenter retrospective study, data of patients undergoing liver stiffness measurements (LSM) in five European centers were collected. TE was performed with FibroScan® (Echosens, France) and ElastPQ® with EPIQ® or Affiniti® systems (Philips, The Netherlands). The agreement between TE and ElastPQ® LSMs was assessed with Lin's concordance correlation coefficient (CCC). Diagnostic performance of ElastPQ® was assessed by the area under receiver operating characteristic (AUROC) curves.

Overall, 664 patients were included: mean age: 54.8(13.5) years, main etiologies: viral hepatitis (83.1%) and NAFLD (7.5%). CCC increased significantly when LSMs with ElastPQ® were obtained with IQR/M ≤ 30% (p < 0.001). The diagnostic performance of ElastPQ® for fibrosis staging also increased if LSM values were obtained with IQR/M ≤ 30%.

Quality criteria should be followed when using ElastPQ® for LSM, since the concordance with TE fibrosis staging was better at an ElastPQ® IQR/M ≤ 30.

The aim of the study was to investigate patient-related factors associated with either reliable or poorly reliable measurement results of ultrasound-based shear wave elastography (SWE) of the liver. A total of 188 patients were analyzed prospectively with binary logistic regression using the interquartile range/median as cutoff to define two groups based on reliable and poorly reliable SWE results. SWE results correlated significantly with liver biopsy. Factors associated with reliable SWE results (i.e., no negative impact on measurements) were age, sex, cirrhosis, antiviral and/or cardiovascular medication, smoking habits and body mass index. Factors associated with poorly reliable SWE results were increased skin-to-liver capsule distance (odds ratio = 3.08, 95% confidence interval: 1.70-5.60) and steatosis (odds ratio = 2.89, 95% confidence interval: 1.33-6.28). These findings indicate that the interquartile range/median as a quality parameter is useful in avoiding poorly reliable SWE results. How best to examine patients with increased skin-to-liver capsule distance is a matter of some controversy, as the incidences of obesity, diabetes and metabolic syndrome are increasing worldwide; however, our results indicate that reliable SWE results can be obtained in this group of patients by using ultrasound-based SWE.

Chronic liver diseases often result in the development of liver fibrosis and ultimately, cirrhosis. Treatment strategies and prognosis differ greatly depending on the severity of liver fibrosis, thus liver fibrosis staging is clinically relevant. Traditionally, liver biopsy has been the method of choice for fibrosis evaluation. Because of liver biopsy limitations, noninvasive methods have become a key research interest in the field. Elastography enables the noninvasive measurement of tissue mechanical properties through observation of shear-wave propagation in the tissue of interest. Increasing fibrosis stage is associated with increased liver stiffness, providing a discriminatory feature that can be exploited by elastographic methods. Ultrasonographic (US) and magnetic resonance (MR) imaging elastographic methods are commercially available, each with their respective strengths and limitations. Here, the authors review the technical basis, acquisition techniques, and results and limitations of US- and MR-based elastography techniques. Diagnostic performance in the most common etiologies of chronic liver disease will be presented. Reliability, reproducibility, failure rate, and emerging advances will be discussed. ^© RSNA, 2018 Online supplemental material is available for this article.