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An image fusion system for estimating the therapeutic effects of radiofrequency ablation on hepatocellular carcinoma Cover

An image fusion system for estimating the therapeutic effects of radiofrequency ablation on hepatocellular carcinoma

Radiology and Oncology
Volume 51 (2017): Issue 3 (September 2017)
By: Nobuyuki Toshikuni,  Yasuhiro Matsue,  Kazuaki Ozaki,  Kaho Yamada,  Nobuhiko Hayashi,  Mutsumi Tsuchishima and  Mikihiro Tsutsumi  
Open Access
|Jul 2017

Figures & Tables

Figure 1

Schema of our IFS. An US monitor shows a reference image (left) and a real-time US image (right) immediately after RFA. Two synchronized straight markers depicted in identical positions in the same intrahepatic vessels ensure correct image fusion. On the reference image, a spherical marker (unfilled green circle) was drawn along the contour of a target tumor (filled black circle). On the real-time US image, a high echoic area (filled white circle) due to RFA-induced microbubbles completely covers the synchronized spherical marker, indicating the exact position of the tumor contour, suggesting potential complete ablation.IFS = image fusion system; RFA = radiofrequency ablation; US = ultrasound
Schema of our IFS. An US monitor shows a reference image (left) and a real-time US image (right) immediately after RFA. Two synchronized straight markers depicted in identical positions in the same intrahepatic vessels ensure correct image fusion. On the reference image, a spherical marker (unfilled green circle) was drawn along the contour of a target tumor (filled black circle). On the real-time US image, a high echoic area (filled white circle) due to RFA-induced microbubbles completely covers the synchronized spherical marker, indicating the exact position of the tumor contour, suggesting potential complete ablation.IFS = image fusion system; RFA = radiofrequency ablation; US = ultrasound

Figure 2

Case 1. A 67-year-old male patient had a 15-mm HCC in segment VI. (A) The HCC is depicted as a low echoic tumor (white arrow) on US. A dot-line represents a puncture line for RFA. (B) A reference CT image (left) and a real-time US image (right) immediately after the first RF electrode insertion in the first RFA session. In this case, reference images were created by retrieving pre-treatment arterial phase images from a dynamic CT. Two synchronized straight markers depicted at the same positions in the same portal vein branches ensured correct image fusion. (C) Another reference CT image depicting the tumor (right) and the corresponding real-time US image (left). On the reference image, a spherical marker was drawn along the tumor contour. On the real-time US image, the tumor is almost invisible because of a high echoic area due to RFA-induced microbubbles. However, the synchronized spherical marker indicates the exact position of the tumor contour. The high echoic area completely covers the synchronized spherical marker, thus suggesting the potential complete ablation. (D) Pre-treatment (left) and post-treatment (right) dynamic CT images. The pre-treatment arterial phase image depicts a hypervascular tumor, while the post-treatment portal phase image depicts an RFA-induced avascular area larger than the original tumor. These findings are suggestive of the achievement of complete ablation after the first RFA session.CT = computed tomography; HCC = hepatocellular carcinoma; RFA = radiofrequency ablation; US = ultrasound
Case 1. A 67-year-old male patient had a 15-mm HCC in segment VI. (A) The HCC is depicted as a low echoic tumor (white arrow) on US. A dot-line represents a puncture line for RFA. (B) A reference CT image (left) and a real-time US image (right) immediately after the first RF electrode insertion in the first RFA session. In this case, reference images were created by retrieving pre-treatment arterial phase images from a dynamic CT. Two synchronized straight markers depicted at the same positions in the same portal vein branches ensured correct image fusion. (C) Another reference CT image depicting the tumor (right) and the corresponding real-time US image (left). On the reference image, a spherical marker was drawn along the tumor contour. On the real-time US image, the tumor is almost invisible because of a high echoic area due to RFA-induced microbubbles. However, the synchronized spherical marker indicates the exact position of the tumor contour. The high echoic area completely covers the synchronized spherical marker, thus suggesting the potential complete ablation. (D) Pre-treatment (left) and post-treatment (right) dynamic CT images. The pre-treatment arterial phase image depicts a hypervascular tumor, while the post-treatment portal phase image depicts an RFA-induced avascular area larger than the original tumor. These findings are suggestive of the achievement of complete ablation after the first RFA session.CT = computed tomography; HCC = hepatocellular carcinoma; RFA = radiofrequency ablation; US = ultrasound

Figure 3

Case 2. A 66-year-old female patient had a 28-mm HCC in segment VIII. (A) The HCC is depicted as a low echoic tumor on US. A dot-line represents a puncture line for RFA. (B) A reference MRI image (left) and a real-time US image (right) immediately after the first RF electrode insertion in the first RFA session. In this case, reference images were created by retrieving pre-treatment hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI. On the reference image, a spherical marker was drawn along the tumor contour. Although the tumor is almost invisible on the real-time US image because of a high echoic area due to RFA-induced microbubbles, the synchronized spherical marker indicates the exact position of the tumor contour. The positional relationship between the high echoic area and the synchronized spherical marker suggests incomplete ablation. (C) A reference MRI image (left) and a real-time US image (right) immediately after the fourth RF electrode insertion in the first RFA session. The extent of the high echoic area due to RFA-induced microbubbles is larger than that after the first RF electrode insertion. The positional relationship between the high echoic area and the synchronized spherical marker suggests potential complete ablation. (D) A pre-treatment MRI image (left) and a post-treatment dynamic CT image (right). The pre-treatment hepatobiliary image depicts a hypointense tumor, while the post-treatment portal phase image depicts an RFA-induced avascular area larger than the original tumor. These findings are suggestive of the achievement of complete ablation after the first RFA session.CT = computed tomography; Gd-EOB-DTPA = gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid; HCC = hepatocellular carcinoma; MRI = magnetic resonance imaging; RFA = radiofrequency ablation; US = ultrasound
Case 2. A 66-year-old female patient had a 28-mm HCC in segment VIII. (A) The HCC is depicted as a low echoic tumor on US. A dot-line represents a puncture line for RFA. (B) A reference MRI image (left) and a real-time US image (right) immediately after the first RF electrode insertion in the first RFA session. In this case, reference images were created by retrieving pre-treatment hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI. On the reference image, a spherical marker was drawn along the tumor contour. Although the tumor is almost invisible on the real-time US image because of a high echoic area due to RFA-induced microbubbles, the synchronized spherical marker indicates the exact position of the tumor contour. The positional relationship between the high echoic area and the synchronized spherical marker suggests incomplete ablation. (C) A reference MRI image (left) and a real-time US image (right) immediately after the fourth RF electrode insertion in the first RFA session. The extent of the high echoic area due to RFA-induced microbubbles is larger than that after the first RF electrode insertion. The positional relationship between the high echoic area and the synchronized spherical marker suggests potential complete ablation. (D) A pre-treatment MRI image (left) and a post-treatment dynamic CT image (right). The pre-treatment hepatobiliary image depicts a hypointense tumor, while the post-treatment portal phase image depicts an RFA-induced avascular area larger than the original tumor. These findings are suggestive of the achievement of complete ablation after the first RFA session.CT = computed tomography; Gd-EOB-DTPA = gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid; HCC = hepatocellular carcinoma; MRI = magnetic resonance imaging; RFA = radiofrequency ablation; US = ultrasound

Baseline characteristics of patients

IFS group (n = 25)Control group (n = 20)P-value

Student’s t-tests and Fisher’s exact probability tests were used for continuous variables and categorical variables, respectively.

Age (years)73 ± 8

Data are expressed as the mean ± standard deviation.

74 ± 9

Data are expressed as the mean ± standard deviation.

0.39
Sex, male/female14/118/120.37
Etiology, viral/non-viral15/1017/30.10
Child-Pugh grade, A/B22/316/40.68
Occurrence, new/recurrent23/218/21.00
Tumor size (mm)19 ± 6

Data are expressed as the mean ± standard deviation.

19 ± 8

Data are expressed as the mean ± standard deviation.

0.42
Tumor location, L/M/A/P2/4/11/80/2/11/70.53
Tumor vascularity, hypo/hyper3/221/190.62
Electrode tip, 2 cm/3 cm9/162/180.08
CEUS guidance for RFA, no/yes22/318/21.00
Artificial ascites and/or pleural effusion, no/yes12/138/120.76
Combined with TACE, no/yes21/418/20.68
DOI: https://doi.org/10.1515/raon-2017-0028 | Journal eISSN: 1581-3207 | Journal ISSN: 1318-2099
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Language: English
Page range: 263 - 269
Submitted on: Dec 3, 2016
|
Accepted on: Jun 29, 2017
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Published on: Jul 18, 2017
Published by: Association of Radiology and Oncology
In partnership with: Paradigm Publishing Services
Publication frequency: 4 issues per year
Keywords:
image fusion,
hepatocellular carcinoma,
radiofrequency ablation
Related subjects:
Medicine,
Clinical medicine,
Internal medicine,
Haematology, oncology,
Radiology

© 2017 Nobuyuki Toshikuni, Yasuhiro Matsue, Kazuaki Ozaki, Kaho Yamada, Nobuhiko Hayashi, Mutsumi Tsuchishima, Mikihiro Tsutsumi, published by Association of Radiology and Oncology
This work is licensed under the Creative Commons Attribution 4.0 License.

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