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Utility of Real-time CT/MRI-US Automatic Fusion System Based on Vascular Matching in Percutaneous Radiofrequency Ablation for Hepatocellular Carcinomas: A Prospective Study



To prospectively evaluate the technical success rate of real-time computed tomography/magnetic resonance imaging and ultrasound (CT/MRI-US) automatic fusion system and the long-term therapeutic efficacy of radiofrequency ablation (RFA) guided by automatic fusion in hepatocellular carcinoma (HCC) patients.

Materials and Methods

139 patients with 151 HCCs were prospectively enrolled for RFA guided by an automatic CT/MRI-US fusion system (PercuNav system, Philips, the Netherlands). Automatic fusion imaging, based on vascular segmentation and registration, was performed by sonographic sweeping at the intercostal plane. The fusion quality, tumor localization confidence and technical feasibility were recorded before and after fusion using a scoring system. Technical success rate of the RFA procedure and local tumor progression (LTP) were assessed during follow-up. Analysis of technical success and LTP was performed using generalized estimating equations and Cox proportional hazard regression analysis.


The success rate of the fusion system was 82.7% (115/139) per patient. The mean sonographic scan time for fusion was 154.4 ± 108.4 s. In patients with successful fusion, the score indicating tumor localization confidence (2.2 ± 0.8 vs. 2.7 ± 0.9) and technical feasibility (2.6 ± 0.8 vs. 3.4 ± 0.7) increased after fusion (p < 0.001). The technical success rate of the RFA procedure was 96.8% (120/124) per tumor in patients with successful fusion, including poorly localized tumors. LTP rates were 8.6%, 12.2% and 15.2% at 1, 2 and 3 years.


The CT/MRI-US automatic fusion system showed a high success rate for image registration and facilitated better feasibility and a high technical success rate of RFA in HCCs, even with poor localization on US.

Level of Evidence

Level 3b, Nonrandomized prospective study

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This study was conducted under technical support from Philips (Best, the Netherlands) and statistical support from Medical Research Collaborating Center (MRCC) of Seoul National University Hospital



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Corresponding author

Correspondence to Jeong Min Lee.

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The authors declare that they have no conflict of interest.

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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

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Informed consent was obtained from all individual participants included in the study.

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Appendix 1

See Table

Table 7 Contraindications for RFA in our institute


Appendix 2

See Table

Table 8 Comparison between patients with success and failure in automatic fusion process


Appendix 3

See Table

Table 9 Results from pre-procedural planning session in entire enrolled patients


Appendix 4

See Table

Table 10 Analysis for technical success/efficacy per tumor


Appendix 5

See Table

Table 11 Risk factor analysis for local tumor progression per tumor in entire enrolled patients


Appendix 6

See Table

Table 12 Comparison of baseline characteristics between subgroups of tumors regarding localization confidence*


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Cite this article

Han, S., Lee, J.M., Lee, D.H. et al. Utility of Real-time CT/MRI-US Automatic Fusion System Based on Vascular Matching in Percutaneous Radiofrequency Ablation for Hepatocellular Carcinomas: A Prospective Study. Cardiovasc Intervent Radiol 44, 1579–1596 (2021).

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  • Hepatocellular carcinoma
  • Radiofrequency ablation
  • CT
  • MRI-US automatic fusion system