US Elastography in Hepatic Fibrosis-Radiology In Training

A comparative study of three ultrasound techniques for liver fibrosis staging

The aim of this study is to assess the agreement and performance of visual transient elastography (ViTE), sound touch elastography (STE), and sound touch quantification (STQ) for liver fibrosis staging using transient elastography (TE) as a standard. We finally enrolled 252 subjects with chronic liver disease (CLD) who underwent ViTE, STE, STQ, and TE examinations simultaneously in our hospital from October 2022 to July 2023. We evaluated the correlation and agreement between various technologies. And also evaluated the performances and optimal cutoffs of ViTE, STE, and STQ . The correlation coefficients of ViTE and TE, STE and TE, STQ and TE were 0.863, 0.709, and 0.727, respectively. The ICC among ViTE, STE, STQ, and TE was 0.911. The area under the receiver operating characteristics (AUROCs) of ViTE, STE, and STQ for detection of TE of ≥5 kPa, ≥10 kPa, ≥15 kPa, and ≥20 kPa were 0.867, 0.771, 0.804; 0.972, 0.935, 0.933; 0.998, 0.973, 0.968; and 1.000, 0.960, 0.954, respectively. The AUROCs of ViTE for detection of lower stages (TE≥5 kPa and ≥10 kPa) were significantly higher than STE and STQ in the overall cohort (ViTE vs. STE: Z  = 2.766, for TE ≥5 kPa; ViTE vs. STE: Z  = 2.145, ; ViTE vs. STQ: Z  = 2.587, for TE ≥10 kPa) (all P < 0.05). These methods all have coincided with performance in more advanced stages (TE ≥15 kPa and ≥20 kPa) (all P  > 0.05). These methods showed excellent correlation and agreement. ViTE performance in more advanced fibrosis differentiation is comparable to the STE and STQ while ViTE is more accurate than STE and STQ to identify patients with mild CLD stage, and can more effectively rule out compensated advanced CLD.

Shear wave velocity values measured by 2D-shear wave elastography are not different between awake and anesthetized cats without clinically significant hepatic fibrosis

Two-dimensional shear wave elastography (2D-SWE) is widely used as a noninvasive method to quantify liver stiffness. In humans, liver stiffness approximates histologic hepatic fibrosis. While histology is the gold standard for diagnosing liver disease, 2D-SWE may be a minimally invasive alternative to biopsy in feline patients. The objectives of this prospective, observational, crossover study were trifold: (1) to assess the feasibility of performing 2D-SWE in awake cats, (2) to determine whether anesthesia altered shear wave velocity (SWV) measurements, and (3) to correlate hepatic stiffness with histologically quantified hepatic fibrosis. Eleven healthy, purpose-bred cats underwent 2D-SWE in awake and anesthetized states. SWV measurements were compared with histologic fibrosis measurements obtained from liver biopsies during the anesthetic period. The mean velocities were not significantly different between awake (1.47 ± 0.18 m/s) and anesthetized (1.47 ± 0.24 m/s) cats. Premedication and anesthetic drugs did not impact mean SWV. There was a higher variability in the SWV values in the awake group. The data points were reliably replicated, with an interquartile range of 0.24 and 0.32 in anesthetized and awake groups, respectively. There was moderate agreement between observers (intraclass correlation coefficient = 0.66). All cats had clinically insignificant fibrosis. There was no correlation between the SWV measurements and the histological fibrosis values. This study demonstrates that 2D-SWE is feasible in awake cats and that the anesthetic protocol employed did not significantly alter mean SWV. This work is the first to histologically validate normal SWV values in cats and show that 2D-SWE cannot differentiate minimal differences in feline hepatic fibrosis.

Deep attenuation transducer to measure liver stiffness in obese patients with liver disease

PURPOSE

Deep attenuation transducers (DAX) are capable of imaging at diagnostic depths of up to 40 cm. The feasibility of DAX for liver stiffness measurement (LSM) has not been reported clinically. We aimed to assess the feasibility and reliability of DAX for LSM.

METHODS

Overall, 219 patients with chronic liver disease were enrolled. The success rate (acquired after ≥ 10 valid measurements) and inadequate measurements (interquartile range/median ≥ 0.3) for DAX were compared with those of conventional convex (c-convex) probes and M and XL probes of vibration-controlled transient elastography.

RESULTS

LSM was successfully performed for all patients using DAX through all degrees of skin-to-liver capsular distance (SCD). Especially in patients with an SCD ≥ 30 mm, the difference in the rate of acquisition of 10 valid measurements was remarkable: M probe (8/33, 24.2%), XL probe (26/33, 78.8%), c-convex probe (33/43, 76.7%), and DAX (44/44, 100%). In patients with an SCD ≥ 30 mm, the inadequate measurement rate of M probe (1/8, 12.5%), XL probe (8/26, 30.8%), and c-convex probe (6/33, 18.2%) was higher than that of DAX (1/43, 2.3%). The areas under the curve for diagnosis of F4 with shear wave speed by c-convex and DAX were 0.916 and 0.918, respectively. Between DAX and c-convex probes, the intraclass correlation coefficient of 0.937 (95% CI 0.918-0.952) was excellent. Bland-Altman plots revealed that there was no statistically significant bias.

CONCLUSION

Liver stiffness measured by DAX is feasible and reliable for all patient populations, while the XL probe is limited to use in obese patients.

Rethinking Liver Fibrosis Staging in Patients with Hepatocellular Carcinoma: New Insights from a Large Two-Center Cohort Study

Background

Hepatocellular carcinoma (HCC) is a prevalent and aggressive malignancy closely related to background chronic liver disease. This study aimed to explore predictive factors associated with background liver fibrosis burden in patients with HCC and sought to construct a practical predictive model for clinical use.

Methods

This large two-center retrospective cohort study evaluated data from Chinese medical centers. Uni- and multivariate ordinal logistic regression analyses were performed to identify variables associated with liver fibrosis stages. Predictive models based on variables identified by multivariate analysis were established in the Derivation Cohort and subjected to internal and external validation. Model performance was evaluated for discriminative and calibration abilities.

Results

Multivariate ordinal logistic regression analysis identified liver fibrosis severity score (LFSS), portal hypertension (PH) severity, plateletcrit (PCT) and model for end-stage liver disease-sodium (MELD-Na) as independent predictors of liver fibrosis stage in HCC patients. Nomograms that integrated these factors disclosed that the area under receiver operating characteristic curves (AUROCs) to predict S1 in the Derivation and External Validation cohorts were 0.850 and 0.919, respectively. Internal validation disclosed C-indexes of 0.823 and 0.833 in the Derivation and External Validation cohorts, respectively, indicating that the nomogram had good and excellent performance for distinguishing between S1 and non-S1 patients. Nomogram performance in the Derivation and External Validation cohorts, respectively, was fair and good to predict stage S2 (AUROCs 0.726, 0.806; C-indexes 0.713, 0.791); poor for S3 (AUROCs 0.648, 0.698; C-indexes 0.616, 0.666); good for S4 (AUROCs 0.812, 0.824; C-indexes 0.804, 0.792); and good for S3+S4 (AUROCs 0.806, 0.840; C-indexes 0.795, 0.811).

Conclusion

We propose new predictive models for the staging of background liver fibrosis in patients with HCC that can be implemented into clinical practice as important complements to hepatic imaging to inform HCC management strategy.