Objective To investigate the feasibility of our new found 3-dimensional contrast-enhanced ultrasound 3D-CEUS registration system as an early assessment of the therapeutic response to radio frequency ablation for liver cancer Methods Twenty-seven patients with 28 lesions accepted 3D-CEUS before and after radio frequency ablation RFA the therapeutic respond to which would be assessed with 3D-CEUS registration system recording the rate of successful registration The CT was considered as the reference standard Results Ten cases 35 7% were successful matched with auto-registration and 24 cases 85 7% were succesful matched with interactive-registration relatively All cases were considered as complete ablated which were confirmed by CECT with 100% accuracy There were two cases achieving ablation margins ≥5 mm without local tumor progression LTP and nineteen cases achieving 0 -4 mm ablation margin with 3 LTP 3-month 6-month and 1-year later Conclusions The 3D-CEUS interactive-registration system can easily assess the therapeutic response of RFA in liver cancer immediately with high accuracy.

Objective:To preliminarily explore the clinical value of three-dimensional ultrasound fusion imaging(3DUS FI) visualization technology in guiding precise needle placement during thermal ablation of hepatocellular carcinoma (HCC).Methods:A total of 56 HCC patients (59 lesions)who underwent 3DUS FI guided thermal ablation were retrospectively analyzed in the First Affiliated Hospital of Sun Yat-sen University from November 2019 to December 2021. All patients were collected with three-dimensional ultrasound volume image before ablation which were fused with real-time two-dimensional ultrasound image for registration, and then the tumor and the safety margin of 5 mm were segmented and marked. Finally, the thermal ablation was performed under three-dimensional visualization. Contrast-enhanced CT/MRI was performed 1 month after thermal ablation to evaluate whether the lesion was completely ablated and measure the ablative margin, and the relationship between ablative margin and the incidence of local tumor progression (LTP) was also analyzed.Results:During the ablation, all lesions could be successfully registered and displayed in three-dimension. Postoperative contrast-enhanced ultrasound showed that all lesions were completely ablated. A total of 37 lesions could be evaluated for ablative efficacy and ablative margin based on contrast-enhanced CT/MRI 1 month after themal ablation, of which 32 (86.5%) lesions achieved complete ablation and obtained at least 5 mm ablative margin. During the follow-up period, LTP was occurred in 4 lesions, 3 of the lesions occurred at the ablative margin< 5 mm. Both 1-year and 2-year cumulative LTP rates were all 7.1%. None of patients had serious complications or deaths associated with thermal ablation.Conclusions:3DUS FI real-time guidance technology is feasible and safe in visually guiding precise needle placement during thermal ablation of HCC.

Objective To compare three-dimensional contrast-enhanced ultrasound ( 3DCEUS) fusion imaging and computed tomography ( CT ) fusion imaging in evaluating ablation margin ( AM ) after radiofrequency ablation ( RFA) for hepatocellular carcinoma ( HCC) . Methods The 3DCEUS images of 60 patients before and after RFA were collected . The AM was evaluated by the self-developed 3DCEUS fusion imaging technique . The consistency of AM evaluation was compared between 3DCEUS and CT fusion imaging . The risk factors of local tumor progression ( LTP) including AM were analyzed . Results The registration success rate of 3DCEUS fusion imaging was 96 .7％ ( 58/60) . Thirty-one cases were in the AM<5 mm group ,and 27 cases were in the AM ≥5 mm group . The consistency of AM evaluation between 3DCEUS and CT fusion imaging was good ( Kappa coefficient = 0 .895 , P < 0 .001) . During a follow-up period ranging 4 .2 to 18 months ,LTP was identified in 5 tumors (8 .6％ ,5/58) .The incidence of LTP with the AM<5 mm was higher than that with the AM ≥5 mm ( P =0 .033) . Conclusions 3DCEUS fusion imaging is feasible for AM evaluation immediately after RFA with high consistency with CT fusion imaging . AM<5 mm evaluated on 3DCEUS fusion immediately after RFA is a risk factor for LTP .