Diagnostic value of Virtual Touch Quantification (VTQ®) for differentiation of hemangiomas from malignant focal liver lesions

The impact of elastography with virtual touch quantification of future remnant liver before major hepatectomy

Background

Liver elastography with virtual touch quantification (VTQ) measures the velocity of the shear wave generated by a short-duration acoustic force impulse, with values expressed in units of velocity (m/s). VTQ can evaluate right or left hepatic lobes separately. VTQ might be appropriate for the evaluation of future remnant liver after hepatectomy.

Methods

We analyzed 95 patients underwent liver elastography with VTQ and both future remnant liver and resected side before hepatectomy of more than two sections, except for central bisectionectomy. We divided the patients into a high VTQ group (≥1.52 m/s, n=37, 39%) and a low VTQ group (<1.52 m/s, n=58, 61%) according to the VTQ of future remnant liver. Transient elastography could not be performed in 22 cases due to tumor size. We defined the group with liver stiffness measurement (LSM) ≥7.9 kPa as the high LSM group (n=29, 40%) and those with LSM <7.9 kPa as the low LSM group (n=44, 60%). We investigated the outcome after hepatectomy and the correlations between the VTQ of future remnant liver and other indicators for hepatic fibrosis.

Results

The high VTQ group showed significantly higher postoperative ascites (19% vs. 3%; P=0.01), pathological fibrosis (19% vs. 5%; P=0.03), and rates of patients with postoperative T-bil ≥2.0 mg/dL (70% vs. 40%; P<0.01). The high LSM group showed no significant postoperative outcomes compared to the low LSM group. The high VTQ group showed a higher frequency of male gender (78% vs. 57%; P=0.03), higher indocyanine green retention rate at 15 min (ICGR15) (10.5% vs. 6.3%; P<0.01), hyaluronic acid (100 vs. 67 ng/mL; P=0.02), type IV collagen 7S (7.6 vs. 5.1 ng/mL; P<0.01), Mac-2 binding protein glycan isomer (M2BPGi) (1.19 vs. 1.00; P=0.01), Fibrosis-4 (FIB-4) index (2.25 vs. 1.76; P=0.01), and aspartate aminotransferase to platelet ratio index (APRI) score (0.64 vs. 0.41; P<0.01). We also observed an especially strong positive correlation between the high VTQ and hyaluronic acid or type IV collagen 7S.

Conclusions

Elastography with VTQ for future remnant liver before major hepatectomy is an accurate and useful method as a preoperative evaluation.

Is There a Place for Elastography in the Diagnosis of Hepatocellular Carcinoma?

Background and Aims: Elastography can provide information regarding tissue stiffness (TS). This study aimed to analyze the elastographic features of hepatocellular carcinoma (HCC) and the factors that influence intratumoral elastographic variability in patients with liver cirrhosis. Methods: This prospective study included 115 patients with liver cirrhosis and hepatocellular carcinoma evaluated between June 2016–November 2019. A total of 88 HCC nodules visualized in conventional abdominal ultrasound (US) met the inclusion criteria and underwent elastographic evaluation. Elastographic measurements (EM) were performed in HCC and liver parenchyma using VTQ (Virtual Touch Quantification), a point shear wave elastography (pSWE) technique. In all patients, we performed contrast-enhanced ultrasound (CEUS), and the final diagnosis of HCC was established by contrast-enhanced-CT or contrast-enhanced-MRI. Results: The mean VTQ values in HCCs were 2.16 ± 0.75 m/s. TS was significantly lower in HCCs than in the surrounding liver parenchyma 2.16 ± 0.75 m/s vs. 2.78 ± 0.92 (p < 0.001). We did not find significant differences between the first five and the last five EM, and the intra-observer reproducibility was excellent ICC: 0.902 (95% CI: 0.87–0.950). However, the tumor size, heterogeneity, and depth correlated with higher intralesional stiffness variability (p < 0.001). Conclusions: VTQ brings additional information for HCC characterization. Intra-observer reproducibility for both HCC and liver parenchyma was excellent. Knowing the stiffness of HCC’s might endorse an algorithm-based approach towards focal liver lesions (FLLs) in liver cirrhosis.

Hepatocellular Carcinoma and Non-Alcoholic Fatty Liver Disease: A Step Forward for Better Evaluation Using Ultrasound Elastography

Simple Summary

Non-alcoholic fatty liver disease (NAFLD) attracts a lot of attention, due to the increasing prevalence and progression to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Consequently, new non-invasive, cost-effective diagnostic methods are needed. This review aims to explore the diagnostic performance of ultrasound (US) elastography in NAFLD and NAFLD-related HCC, adding a new dimension to the conventional US examination—the liver stiffness quantification. The vibration controlled transient elastography (VCTE), and 2D-Shear wave elastography (2D-SWE) are effective in staging liver fibrosis in NAFLD. VCTE presents the upside of assessing steatosis through the controlled attenuation parameter. Hereby, we critically reviewed the elastography techniques for the quantitative characterization of focal liver lesions (FLLs), focusing on HCC: Point shear wave elastography and 2D-SWE. 2D-SWE presents a great potential to differentiate malignant from benign FLLs, guiding the clinician towards the next diagnostic steps. As a disease-specific surveillance tool, US elastography presents prognostic capability, improving the NAFLD-related HCC monitoring.

Abstract

The increasing prevalence of non-alcoholic fatty liver disease (NAFLD) in the general population prompts for a quick response from physicians. As NAFLD can progress to liver fibrosis, cirrhosis, and even hepatocellular carcinoma (HCC), new non-invasive, rapid, cost-effective diagnostic methods are needed. In this review, we explore the diagnostic performance of ultrasound elastography for non-invasive assessment of NAFLD and NAFLD-related HCC. Elastography provides a new dimension to the conventional ultrasound examination, by adding the liver stiffness quantification in the diagnostic algorithm. Whilst the most efficient elastographic techniques in staging liver fibrosis in NAFLD are vibration controlled transient elastography (VCTE) and 2D-Shear wave elastography (2D-SWE), VCTE presents the upside of assessing steatosis through the controlled attenuation parameter (CAP). Hereby, we have also critically reviewed the most important elastographic techniques for the quantitative characterization of focal liver lesions (FLLs), focusing on HCC: Point shear wave elastography (pSWE) and 2D-SWE. As our paper shows, elastography should not be considered as a substitute for FLL biopsy because of the stiffness values overlap. Furthermore, by using non-invasive, disease-specific surveillance tools, such as US elastography, a subset of the non-cirrhotic NAFLD patients at risk for developing HCC can be detected early, leading to a better outcome. A recent ultrasomics study exemplified the wide potential of 2D-SWE to differentiate benign FLLs from malignant ones, guiding the clinician towards the next steps of diagnosis and contributing to better long-term disease surveillance.