Detection and characterization of small superficially located focal liver lesions by contrast-enhanced ultrasound with high frequency transducers

Abstract

Aim: To evaluate the benefits of contrast-enhanced ultrasound (CEUS) with high frequency transducers in the detection and characterization of small superficially located focal liver lesions (FLLs).Material and methods: From January 2015 to October 2016, 27 superficial FLLs detected by MRI were examined, first with the low frequency convex transducer (1-5 MHz) and afterwards with a high frequency transducer (7.5-12 MHz). High frequency dynamic CEUS was performed after a bolus injection of 2.4 ml SonoVue®. FLLs were confirmed by histopathology after surgery (n=18) or ultrasound guided 18-gauge core-needle biopsy (n=8), or by MRI follow-up (n =1).Results: The mean diameter of FLLs was 10.5±3.1 mm, and meandepth was 6.2±5.3 mm. While using a high frequency transducerthe detection rate of FLLs (100%, 27/27) was significantly higher than low frequency transducer (25.9%, 7/27) (p<0.05). The overall sensitivity, specificity and diagnostic accuracy were significantly improved by CEUS with a high frequency transducer (sensitivity 88.9%; specificity 92.6%; accuracy 96.2%).Conclusion: Combining CEUS with the performance of high-frequency transducers is a promising technique to improve the detection and accurate diagnosis of small and superficial FLLs appearing indistinctive on BMUS.

Guidelines for the Diagnosis and Treatment of Primary Liver Cancer (2022 Edition)

“…Contrast-enhanced US can dynamically visualize real-time changes in vascular perfusion in liver tumors and identify liver tumors of different natures. The use of contrast-enhanced US intraoperatively may identify small occult lesions, guide locoregional treatment in real time, and predict the postoperative efficacy/outcomes of locoregional treatment of HCC [13][14][15][16] (evidence level 3, recommendation A). US combined with imaging navigation technology offers a tool for the precise localization and ablation of HCC, especially occult HCC that cannot be visualized by conventional US [13,17] (evidence level 4, recommendation B).…”

Current Concepts of Precancerous Lesions of Hepatocellular Carcinoma: Recent Progress in Diagnosis

“…The use of computed tomography (CT) or magnetic resonance imaging (MRI) may fail to detect arterial phase hyperenhancement (APHE) due to missed arterial phases, and contrast-enhanced ultrasound (CEUS) is superior to CT and MRI in the detection of nodal vascular hyperfunction [ 80 , 81 ]. CEUS has demonstrated significant improvements in the accuracy of US in identifying focal liver lesions due to the ability to distinguish between benign and malignant lesions based on vascular patterns in the arterial, portal, and sinusoidal phases [ 82 , 83 ]. Imaging fusion, which combines CEUS and MRI, is a promising technique for improving the detection, accurate localization, and accurate diagnosis of HCC, especially small and atypical HCCs that are not visible in conventional ultrasound [ 84 ].…”