Shear wave elastography results correlate with liver fibrosis histology and liver function reserve

Diagnosis of liver fibrosis and liver function reserve through non-invasive multispectral photoacoustic imaging

Liver function reserve (LFR) is the sum of remnant functional hepatic cells after liver injury. In the pathologic process of liver fibrosis (LF), LFR is impaired. LFR assessment can help determine the safe scope of liver resection or drug regimen and predict prognosis of patients with liver disease. Here, we used a photoacoustic imaging (PAI) system to assess LF and LFR in rabbit models. We performed PAI, ultrasound elastography and biopsy for 21 rabbits developing none (n = 6) and LF (n = 15). In vivo indocyanine green (ICG) measurements by PAI showed that LF group presented a significantly attenuated ICG clearance compared to control group, indicating LFR impairment of LF. Another finding was a significantly higher collagen photoacoustic signal intensity value was observed in LF both in vivo and in vitro. Our findings demonstrated that PAI was potentially effective to evaluate LFR and collagen accumulation of LF.

Machine Learning-Based Development of Nomogram for Hepatocellular Carcinoma to Predict Acute Liver Function Deterioration After Drug-Eluting Beads Transarterial Chemoembolization

RATIONALE AND OBJECTIVES

Acute liver function deterioration (ALFD) following drug-eluting beads transarterial chemotherapy embolism (DEB-TACE) was considered a risk factor for prognosis in patients with hepatocellular carcinoma (HCC). In this study, we aimed to develop and validate a nomogram for the prediction of ALFD after DEB-TACE.

MATERIALS AND METHODS

A total of 288 patients with HCC from a single center were randomly divided into a training dataset (n = 201) and a validation dataset (n = 87). The univariate and multivariate logistic regression analyses were performed to determine risk factors for ALFD. The least absolute shrinkage and selection operator (LASSO) was applied to identify the key risk factors and fit a model. The performance, calibration, and clinical utility of the predictive nomogram were assessed using receiver operating characteristic curves, calibration curves, and decision curve analysis (DCA).

RESULTS

LASSO regression analysis determined six risk factors with fibrosis index based on four factors (FIB-4) as the independent factor for the occurrence of ALFD after DEB-TACE. Gamma-glutamyltransferase, FIB-4, tumor extent, and portal vein invasion were integrated into the nomogram. In both the training and validation cohorts, the nomogram demonstrated promising discrimination with AUC of 0.762 and 0.878, respectively. The calibration curves and DCA revealed good calibration and clinical utility of the predictive nomogram.

CONCLUSION

The nomogram-based risk of ALFD stratification may improve clinical decision-making and surveillance protocols for patients with a high risk of ALFD after DEB-TACE.

Tomoelastography based on multifrequency MR elastography predicts liver function reserve in patients with hepatocellular carcinoma: a prospective study

BACKGROUND

Estimating liver function reserve is essential for preoperative surgical planning and predicting post-hepatectomy complications in patients with hepatocellular carcinoma (HCC). We investigated hepatic viscoelasticity quantified by tomoelastography, a multifrequency magnetic resonance elastography technique, to predict liver function reserve.

METHODS

One hundred fifty-six patients with suspected HCC (mean age, 60 ± 1 years; 131 men) underwent preoperative tomoelastography examination between July 2020 and August 2021. Sixty-nine were included in the final analysis, and their 15-min indocyanine green retention rates (ICG-R15s) were obtained to determine liver function reserve. Tomoelastography quantified the shear wave speed (c, m/s), which represents stiffness, and loss angle (φ, rad), which represents fluidity. Both were correlated with the ICG-R15. A prediction model based on logistic regression for major hepatectomy tolerance (ICG-R15 ≥ 14%) was established.

RESULTS

Patients were assigned to either the ICG-R15 < 14% (n = 50) or ICG-R15 ≥ 14% (n = 19) group. Liver c (r = 0.617) and φ (r = 0.517) were positively correlated with the ICG-R15 (both p < 0.001). At fibrosis stages F1-2, φ was positively correlated with the ICG-R15 (r = 0.528; p = 0.017), but c was not (p = 0.104). At stages F3-4, c (r = 0.642; p < 0.001) and φ (r = 0.377; p = 0.008) were both positively correlated with the ICG-R15. The optimal cutoffs of c and φ for predicting ICG-R15 ≥ 14% were 2.04 m/s and 0.79 rad, respectively. The area under the receiver operating characteristic curve was higher for c (0.892) than for φ (0.779; p = 0.045).

CONCLUSIONS

Liver stiffness and fluidity, quantified by tomoelastography, were correlated with liver function and may be used clinically to noninvasively assess liver function reserve and stratify treatments.

Effects of Solanum lycopersicum L. (tomato) against isoniazid and rifampicin induced hepatotoxicity in wistar albino rats

Anti-tuberculosis drugs are reported to cause hepatotoxicity, which varies from asymptomatic rise of the hepatic enzymes. Hepatoprotective plants plays important role to protect liver. This study investigated the hepatoprotective potential of the Solanum lycopersicum in rats intoxicated with Isoniazid and Rifampicin (INH+RIF) to induce hepatotoxicity. Thirty wistar albino rats were divided into five groups of six animals each. Group 1 rats were kept control while groups II, III, IV and V were administered with INH+RIF (75+150 mg/kg) orally, for seven consecutive days. For treatment, rats in group III received silymarin while animals in group IV and V were provided with 40 mg/kg and 80 mg/kg of Solanum lycopersicum extract, respectively. On day 0 and 8th blood samples were collected for the analysis of hepatic biomarkers. The data were subjected to one-way ANOVA and Bonferroni's post hoc test for statistical analysis. Hepatotoxicity induced by INH+RIF resulted in significant elevation of serum hepatic enzymes including Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Alkaline phosphatase (ALP), and total bilirubin while decreased the albumin level. The Solanum lycopersicum at dose of 80 mg/kg significantly reduced the hepatic enzymes AST, ALT, ALP and bilirubin while the albumin level was significantly increased. The treatment had non-significant effect on body and liver weight. Drug induced hepatotoxicity can be effectively treated with Solanum lycopersicum at 80 mg/kg dose.

Feasibility of liver stiffness measured using two-dimensional shear wave elastography in assessing preoperative liver function for patients with hepatocellular carcinoma

OBJECTIVES

To evaluate the feasibility of liver stiffness (LS) measured using two-dimensional shear wave elastography (2D SWE) in assessing preoperative liver function for patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

A total of 143 patients who underwent surgical resection for HCC between August 2018 and December 2019 were enrolled prospectively. LS measurement, liver function tests including serum biochemical indicators, and indocyanine green (ICG) clearance test were performed preoperatively. Child-Pugh (CP) score, Albumin-bilirubin (ALBI) score and Model for End-Stage Liver Disease score were calculated. ICG retention rate at 15 min (ICG R15) and ICG elimination rate constant (ICG K) were determined automatically. Fibrosis stage was determined based on pathological findings. The association between LS and serum biochemical indicators, liver function scores, and the ICG results were analyzed.

RESULTS

Weak to moderate correlations were identified between LS and biochemical indicators of liver function (all p < 0.01). Weak correlation was identified between LS and CP score, and between LS and ALBI score (all p < 0.001). Moderate correlation was identified between LS and ICG R15 (Pearson r = 0.62, p < 0.001), and between LS and ICG K value (Pearson r =  - 0.49, p < 0.001). The best cutoff of LS to discriminate a normal ICG R15 was 10.6 kPa, with area under the curve (AUC), sensitivity, specificity of 0.874, 0.900 and 0.724, respectively.

CONCLUSIONS

LS determined using 2D SWE could be a potential tool for the preoperative evaluation of liver function in patients with HCC.

Comparison of shear-wave velocities obtained with shear-wave elastography of various peripheral lymph nodes in healthy Beagles

OBJECTIVE

To compare shear-wave velocities (SWVs) with shear-wave elastography of various peripheral lymph nodes (LNs).

ANIMALS

11 healthy Beagles.

PROCEDURES

For each dog, bilateral mandibular, medial retropharyngeal, superficial cervical, axillary, superficial inguinal, and popliteal LNs were evaluated with shear-wave elastography in sagittal and transverse scanning planes. Depth of each lymph node was recorded, and intra- and interobserver reliability was determined.

RESULTS

SWVs for all LNs were significantly higher in the sagittal scanning plane, compared with those in the transverse scanning plane. The SWV of the most superficial LN, the mandibular LN, was significantly higher, compared with that for the other LNs, except for the medial retropharyngeal LN. The SWV of the deepest LN, the medial retropharyngeal LN, was as high as that for the mandibular LN. Intra- and interobserver reliability was excellent.

CONCLUSIONS AND CLINICAL RELEVANCE

SWVs for normal peripheral LNs of Beagles may serve as a reference to compare with those for other breeds and diseased LNs. Scanning plane, LN depth, and interfering tissues between the LN and the transducer may affect SWV. Shear-wave elastography may not be operator dependent.

Comparison of shear-wave velocities obtained with shear-wave elastography of various peripheral lymph nodes in healthy Beagles

OBJECTIVE

To compare shear-wave velocities (SWVs) with shear-wave elastography of various peripheral lymph nodes (LNs).

ANIMALS

11 healthy Beagles.

PROCEDURES

For each dog, bilateral mandibular, medial retropharyngeal, superficial cervical, axillary, superficial inguinal, and popliteal LNs were evaluated with shear-wave elastography in sagittal and transverse scanning planes. Depth of each lymph node was recorded, and intra- and interobserver reliability was determined.

RESULTS

SWVs for all LNs were significantly higher in the sagittal scanning plane, compared with those in the transverse scanning plane. The SWV of the most superficial LN, the mandibular LN, was significantly higher, compared with that for the other LNs, except for the medial retropharyngeal LN. The SWV of the deepest LN, the medial retropharyngeal LN, was as high as that for the mandibular LN. Intra- and interobserver reliability was excellent.

CONCLUSIONS AND CLINICAL RELEVANCE

SWVs for normal peripheral LNs of Beagles may serve as a reference to compare with those for other breeds and diseased LNs. Scanning plane, LN depth, and interfering tissues between the LN and the transducer may affect SWV. Shear-wave elastography may not be operator dependent.

Liver Stiffness Measured by Two-Dimensional Shear Wave Elastography for Predicting Symptomatic Post-hepatectomy Liver Failure in Patients with Hepatocellular Carcinoma

OBJECTIVES

To evaluate the ability of liver stiffness (LS) measured by two-dimensional shear wave elastography (2D SWE) to predict symptomatic post-hepatectomy liver failure (SPHLF) in patients with hepatocellular carcinoma (HCC).

METHODS

A total of 119 patients who underwent hepatectomy for HCC between August 2018 and July 2019 were enrolled. Preoperative assessments for LS and other clinicopathological tests were performed in all patients. Univariate and multivariate analyses were conducted for the risk factors of SPHLF. Further subgroup analysis was performed according to multivariate analysis results.

RESULTS

SPHLF occurred in 38 patients (31.9%). The best cutoff value of LS for predicting SPHLF was 9.5 kPa. Multivariate analysis identified LS ≥ 9.5 kPa, greater Child-Turcotte-Pugh (CTP) grade, and major hepatectomy as independent predictors of SPHLF. Based on the extent of hepatectomy, CTP grade could stratify the risk of SPHLF in the minor hepatectomy group (12.2% vs. 100.0%, p = 0.001), whereas LS was superior in predicting SPHLF in the major hepatectomy group (18.9% vs. 72.4%, p < 0.001). In patients with CTP grade A, LS could further stratify the risks of SPHLF in both the minor and major hepatectomy groups (3.7% vs. 22.7%, p = 0.043; 17.6% vs. 70.4%, p < 0.001, respectively).

CONCLUSIONS

LS measured using 2D SWE could predict SPHLF using the best cutoff value of 9.5 kPa. CTP grade was a stronger indicator of SPHLF in minor hepatectomy, whereas LS was more effective in selecting candidates for major hepatectomy. LS could further stratify the risk of SPHLF in CTP grade A patients, regardless of the extent of hepatectomy.

Evaluation of serum lidocaine/monoethylglycylxylidide concentration to assess shunt closure in dogs with extrahepatic portosystemic shunts

BACKGROUND

Liver function tests do not always normalize despite successful attenuation of extrahepatic portosystemic shunts (EHPSS).

OBJECTIVES

Assess the lidocaine/monoethylglycylxylidide (MEGX) test to determine liver perfusion after EHPSS closure.

ANIMALS

Twenty dogs with EHPSS.

METHODS

A prospective cohort study was performed and all dogs were tested at diagnosis, 1, 3, and 6 months postoperatively. After collecting a baseline blood sample (T0), 1 mg/kg body weight of lidocaine was injected intravenously. Fifteen (T15) and 30 minutes (T30) later, blood was collected. Plasma concentrations of lidocaine and its metabolites MEGX and glycylxylidide (GX) were determined, using a high-performance liquid chromatography with electrospray ionization tandem mass spectrometry method. Three months postoperatively, transsplenic portal scintigraphy was performed to determine EHPSS closure.

RESULTS

At T15, median MEGX concentrations were higher in dogs with closed EHPSS compared to diagnosis (33.73 ng/mL [21.11-66.44 ng/mL] vs 13.74 ng/mL [7.25-21.93 ng/mL]; P < .001), but were not different (12.28 ng/mL [10.62-23.17 ng/mL] vs 13.74 ng/mL [7.25-21.93 ng/mL]) in dogs with persistent shunting. Sensitivity to determine shunt closure for MEGX at T15 was 96.2% (95% confidence interval [CI]: 78.4-99.8) and specificity 82.8% (95% CI: 63.5-93.5).

CONCLUSIONS AND CLINICAL IMPORTANCE

The lidocaine/MEGX test is a promising, rapid, and noninvasive blood test that seems helpful to differentiate dogs with closed EHPSS and dogs with persistent shunting after gradual attenuation.

Changes in Liver Mechanical Properties and Water Diffusivity During Normal Pregnancy Are Driven by Cellular Hypertrophy

During pregnancy, the body’s hyperestrogenic state alters hepatic metabolism and synthesis. While biochemical changes related to liver function during normal pregnancy are well understood, pregnancy-associated alterations in biophysical properties of the liver remain elusive. In this study, we investigated 26 ex vivo fresh liver specimens harvested from pregnant and non-pregnant rats by diffusion-weighted imaging (DWI) and magnetic resonance elastography (MRE) in a 0.5-Tesla compact magnetic resonance imaging (MRI) scanner. Water diffusivity and viscoelastic parameters were compared with histological data and blood markers. We found livers from pregnant rats to have (i) significantly enlarged hepatocytes (26 ± 15%, p < 0.001), (ii) increased liver stiffness (12 ± 15%, p = 0.012), (iii) decreased viscosity (−23 ± 14%, p < 0.001), and (iv) increased water diffusivity (12 ± 11%, p < 0.001). In conclusion, increased stiffness and reduced viscosity of the liver during pregnancy are mainly attributable to hepatocyte enlargement. Hypertrophy of liver cells imposes fewer restrictions on intracellular water mobility, resulting in a higher hepatic water diffusion coefficient. Collectively, MRE and DWI have the potential to inform on structural liver changes associated with pregnancy in a clinical context.

Liver and spleen elastography of dogs affected by brachycephalic obstructive airway syndrome and its correlation with clinical biomarkers

The purpose of this study is to determine whether the brachycephalic obstructive airway syndrome (BOAS) is correlated to alterations in liver and spleen elasticity. Forty-eight brachycephalic and 22 mesocephalic dogs were submitted to a BOAS functional assessment, laboratory tests, abdominal ultrasound and liver and spleen Acoustic Radiation Force Impulse (ARFI) elastography. Dogs clinically affected by BOAS had higher values of liver stiffness (p < 0.001) than healthy dogs: medial lobes (1.57 ± 0.37 m/s), left and right lateral lobes (1.54 ± 0.50 m/s, 1.23 ± 0.28 m/s, respectively) and caudate lobe (1.28 ± 0.42 m/s). Compared to the mesocephalic group, the brachycephalic group (BOAS clinically affected and unaffected dogs) had higher spleen (2.51 ± 0.45 m/s; p < 0.001) and liver stiffness (p < 0.001): medial lobes (1.53 ± 0.37 m/s), left and right lateral lobes (1.47 ± 0.47 m/s, 1.20 ± 0.30 m/s, respectively) and caudate lobe (1.23 ± 0.40 m/s). Principal component analysis explained 70% of the variances composed by liver stiffness increase, erythrocytes and alanine aminotransferase reduction. Brachycephalic dogs had higher spleen and liver stiffness and a subacute inflammatory state, which represent another BOAS systemic effect. Consequently, these dogs can be at higher risk of hepatic disorders compared with mesocephalic dogs, similarly to humans affected by sleep apnea syndrome.

Stiffness and Anisotropy Effect on Shear Wave Elastography: A Phantom and in Vivo Renal Study

Tissue elasticity is related to the pathologic state of kidneys and can be measured using shear wave elastography (SWE). However, SWE quantification has not been rigorously validated. The aim of this study was to evaluate the accuracy of SWE-measured stiffness and the effect of tissue anisotropy on SWE measurements. Point SWE (pSWE), 2-D SWE and dynamic mechanical analysis (DMA) were used to measure stiffness and evaluate the effect of tissue anisotropy on the measurements. SWE and DMA were performed on phantoms of different gelatin concentrations. In the tissue anisotropy study, SWE and DMA were performed on the outer cortex of sheep kidneys. In the in vivo study, 15 patients with different levels of interstitial fibrosis were recruited for pSWE measurements. Another 10 healthy volunteers were recruited for tissue anisotropy studies. SWE imaging revealed a non-linear increase with gelatin concentration. There was a significant correlation between pSWE and 2-D SWE, leading to the establishment of a linear regression equation between the two SWE ultrasound measurements. In the anisotropy study, the median difference in stiffness between shear waves oriented at 0° and 90° towards the pyramid axis was significant. In the in vivo study, there was a strong positive linear correlation between pSWE and the percentage of interstitial fibrosis. There was a significant difference in the Young's modulus (YM) between severities of fibrosis. The mean YM values were lower in control patients than in patients with mild, moderate and severe fibrosis. YM values were also significantly higher when shear waves were oriented at 0° toward the pyramid axis. Tissue stiffness and anisotropy affects SWE measurements. These factors should be recognized before applying SWE for the interpretation of measured values.

Comparison of Shear Wave Elastography and Conventional Ultrasound in Assessing Kidney Function as Measured Using 51Cr-ethylenediaminetetraacetic Acid and 99Tc-Dimercaptosuccinic Acid

The purpose of this study was to assess the potential of shear wave elastography (SWE) as an indicator of abnormal kidney function defined by radiolabeled glomerular filtration rate (GFR). Fifty-seven patients referred for ⁵¹Cr-ethylenediaminetetraacetic acid GFR and ^99mTc-dimercaptosuccinic acid renal scintigraphy were included. Young's modulus (YM) measured with SWE and kidney length, volume, cortical thickness and parenchymal echogenicity measured with conventional ultrasound were correlated with patients' GFR and renal scintigraphy results. Spearman correlation coefficients between SWE and GFR were negative for the right (r = -0.635, p < 0.0001) and left (r = -0.817, p < 0.0001) kidneys. Positive correlations between left renal cortical thickness (r = 0.381, p = 0.04) and left kidney volume (r = 0.356, p = 0.019) with GFR were reported. SWE correctly predicted the dominant functioning kidney in 94.7% of cases. The area under the receiver operating characteristic curve for SWE (0.800) was superior to that for conventional ultrasound (0.252-0.415). The cutoff value of ≥5.52 kPa suggested a kidney function ≤60 mL/min/1.73 m² (82.4% sensitivity and 76.2% specificity). SWE has advantages over conventional ultrasound in assessing kidney function and distinguishing the dominant functioning kidney.

Evaluation of liver and spleen stiffness of healthy dogs by use of two-dimensional shear wave elastography

OBJECTIVE

To assess liver and spleen stiffness in healthy dogs by use of a novel 2-D shear wave elastography (SWE) technique and to investigate the repeatability and reproducibility of the technique.

ANIMALS

8 healthy adult Beagles.

PROCEDURES

2-D SWE was performed on each dog to assess liver and spleen stiffness. Repeatability (intraday variability) and reproducibility (interday variability) of 2-D SWE were investigated. For all 8 dogs, 2-D SWE was performed 3 times in 1 day (4-hour intervals) and on 3 separate days (1-week interval). Data were expressed as mean ± SD values for shear wave velocity and the Young modulus in the liver and spleen. Intraday and interday coefficients of variation were assessed for all variables.

RESULTS

Mean ± SD shear wave velocity obtained for the liver and spleen was 1.51 ± 0.08 m/s and 2.18 ± 0.27 m/s, respectively. Mean value for the Young modulus obtained for the liver and spleen was 6.93 ± 0.79 kPa and 14.66 ± 3.79 kPa, respectively. Elasticity values were significantly higher for the spleen than for the liver. Intraday and interday coefficients of variation for all variables were < 25% (range, 3.90% to 20.70%).

CONCLUSIONS AND CLINICAL RELEVANCE

2-D SWE was a feasible technique for assessing liver and spleen stiffness of healthy dogs. Future studies on the application of 2-D SWE for dogs with chronic hepatitis, cirrhosis, and portal hypertension are needed to evaluate the clinical applicability of 2-D SWE.

Correlation between acoustic radiation force impulse (ARFI)-based tissue elasticity measurements and perfusion parameters acquired by perfusion CT in cirrhotic livers: a proof of principle

PURPOSE

To investigate whether liver stiffness measured by acoustic radiation force impulse (ARFI) sonoelastography always correlates with the liver perfusion parameters quantified by perfusion CT in patients with known liver cirrhosis.

METHODS

Sonoelastography and perfusion CT were performed in 50 patients (mean age 65.5; range 45-87 years) with liver cirrhosis, who were classified according to Child-Pugh into class A (30/50, 60%), B (17/50, 34%), and C (3/50, 6%). For standardized ARFI measurements in the left liver lobe at a depth of 4 cm, a convex 6-MHz probe was used. CT examinations were performed using 80 kV, 100 mAs, and 50 ml of iodinated contrast agent injected at 5 ml/s. Using standardized region-of-interest measurements, we quantified arterial, portal venous, and total liver perfusion.

RESULTS

There was a significant linear correlation between tissue stiffness and arterial liver perfusion (p = 0.015), and also when limiting the analysis to patients with histology (p = 0.019). In addition, there was a positive correlation between the total blood supply (arterial + portal-venous liver perfusion) to the liver and tissue stiffness (p = 0.001; with histology, p = 0.027). Shear wave velocity increased with higher Child-Pugh stages (p = 0.013).

CONCLUSION

The degree of tissue stiffness in cirrhotic livers correlates expectedly-even if only moderately-with the magnitude of arterial liver perfusion and total liver perfusion. As such, liver elastography remains the leading imaging tool in assessing liver fibrosis.

Shear wave elastography in the evaluation of renal parenchymal stiffness in patients with chronic kidney disease

OBJECTIVE

To investigate the use of shear wave elastography (SWE)-derived estimates of Young's modulus (YM) as an indicator to detect abnormal renal tissue diagnosed by estimated glomerular filtration rate (eGFR).

METHODS

The study comprised 106 chronic kidney disease (CKD) patients and 203 control subjects. Conventional ultrasound was performed to measure the kidney length and cortical thickness. SWE imaging was performed to measure renal parenchymal stiffness. Diagnostic performance of SWE and conventional ultrasound were correlated with serum creatinine, urea levels and eGFR.

RESULTS

Pearson's correlation coefficient revealed a negative correlation between YM measurements and eGFR (r = -0.576, p < 0.0001). Positive correlations between YM measurements and age (r = 0.321, p < 0.05), serum creatinine (r = 0.375, p < 0.0001) and urea (r = 0.287, p < 0.0001) were also observed. The area under the receiver operating characteristic curve for SWE (0.87) was superior to conventional ultrasound alone (0.35-0.37). The cut-off value of less or equal to 4.31 kPa suggested a non-diseased kidney (80.3% sensitivity, 79.5% specificity).

CONCLUSION

SWE was superior to renal length and cortical thickness in detecting CKD. A value of 4.31 kPa or less showed good accuracy in determining whether a kidney was diseased or not. Advances in knowledge: On SWE, CKD patients show greater renal parenchymal stiffness than non-CKD patients. Determining a cut-off value between normal and diseased renal parenchyma may help in early non-invasive detection and management of CKD.

Quantitative assessment of liver fibrosis using shore durometer

Purpose

The purpose of the present study was to investigate whether hardness of liver surface correlated with degree of liver fibrosis, and its association with posthepatectomy liver failure (PHLF).

Methods

A shore durometer was used to measure hepatic hardness in 41 patients with hepatocellular carcinoma (HCC) and in 10 patients with normal liver. We investigated how hepatic hardness correlates with various values indicating the degree of liver fibrosis, and how it correlates with PHLF.

Results

In the normal liver group, the surface shore units (SU) was 15.06 ± 2.64. In the HCC group, there was a correlation between surface SU and preoperative results indicating liver fibrosis. Among patients with PHLF after resecting over 3 segments, the surface SU of patients with grade A PHLF was 21.85 ± 5.63, and the surface SU of patients with grade C PHLF was 35.75 ± 9.26. In patients with PHLF after resecting 2 or less segments, the surface SU of patients with PHLF grade A was 20.95 ± 5.18, and the surface SU of patients with PHLF grade B was 31.60 ± 5.57. In predicting PHLF, surface SU was more effective than preoperative platelet count, spleen volume, or liver fibrosis index.

Conclusion

Hepatic hardness measured by the shore durometer was correlated with the degree of liver fibrosis. Liver surface SU was a more effective parameter for predicting PHLF, as compared to other indicators evaluated before hepatectomy. The decision to perform major hepatectomy should be reconsidered in cases with a liver surface SU of >30.

Fibrosis imaging: Current concepts and future directions

Fibrosis plays an important role in many different pathologies. It results from tissue injury, chronic inflammation, autoimmune reactions and genetic alterations, and it is characterized by the excessive deposition of extracellular matrix components. Biopsies are routinely employed for fibrosis diagnosis, but they suffer from several drawbacks, including their invasive nature, sampling variability and limited spatial information. To overcome these limitations, multiple different imaging tools and technologies have been evaluated over the years, including X-ray imaging, computed tomography (CT), ultrasound (US), magnetic resonance imaging (MRI), positron emission tomography (PET) and single-photon emission computed tomography (SPECT). These modalities can provide anatomical, functional and molecular imaging information which is useful for fibrosis diagnosis and staging, and they may also hold potential for the longitudinal assessment of therapy responses. Here, we summarize the use of non-invasive imaging techniques for monitoring fibrosis in systemic autoimmune diseases, in parenchymal organs (such as liver, kidney, lung and heart), and in desmoplastic cancers. We also discuss how imaging biomarkers can be integrated in (pre-) clinical research to individualize and improve anti-fibrotic therapies.