title: Automatic Registration between Real-Time Ultrasonography and Pre-Procedural Magnetic Resonance Images: A Prospective Comparison between Two Registration Methods by Liver Surface and Vessel and by Liver Surface Only.
abstract: The aim of this study was to compare the accuracy of and the time required for image fusion between real-time ultrasonography (US) and pre-procedural magnetic resonance (MR) images using automatic registration by a liver surface only method and automatic registration by a liver surface and vessel method. This study consisted of 20 patients referred for planning US to assess the feasibility of percutaneous radiofrequency ablation or biopsy for focal hepatic lesions. The first 10 consecutive patients were evaluated by an experienced radiologist using the automatic registration by liver surface and vessel method, whereas the remaining 10 patients were evaluated using the automatic registration by liver surface only method. For all 20 patients, image fusion was automatically executed after following the protocols and fused real-time US and MR images moved synchronously. The accuracy of each method was evaluated by measuring the registration error, and the time required for image fusion was assessed by evaluating the recorded data using in-house software. The results obtained using the two automatic registration methods were compared using the Mann-Whitney U-test. Image fusion was successful in all 20 patients, and the time required for image fusion was significantly shorter with the automatic registration by liver surface only method than with the automatic registration by liver surface and vessel method (median: 43.0 s, range: 29-74 s vs. median: 83.0 s, range: 46-101 s; p = 0.002). The registration error did not significantly differ between the two methods (median: 4.0 mm, range: 2.1-9.9 mm vs. median: 3.7 mm, range: 1.8-5.2 mm; p = 0.496). The automatic registration by liver surface only method offers faster image fusion between real-time US and pre-procedural MR images than does the automatic registration by liver surface and vessel method. However, the degree of accuracy was similar for the two methods.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ah Yeong
authors.initials: AY
authors.lastname: Kim
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Electronic address: leeminwoo0@gmail.com.
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Lee
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Dong Ik
authors.initials: DI
authors.lastname: Cha
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea.
authors.forename: Hyo Keun
authors.initials: HK
authors.lastname: Lim
authors.affiliation: Medical Imaging R&D Group, Health & Medical Equipment Business, Samsung Electronics Company, Ltd., Seoul, Korea.
authors.forename: Young-Taek
authors.initials: YT
authors.lastname: Oh
authors.affiliation: Medical Imaging R&D Group, Health & Medical Equipment Business, Samsung Electronics Company, Ltd., Seoul, Korea.
authors.forename: Ja-Yeon
authors.initials: JY
authors.lastname: Jeong
authors.affiliation: Medical Imaging R&D Group, Health & Medical Equipment Business, Samsung Electronics Company, Ltd., Seoul, Korea.
authors.forename: Jung-Woo
authors.initials: JW
authors.lastname: Chang
authors.affiliation: Medical Imaging R&D Group, Health & Medical Equipment Business, Samsung Electronics Company, Ltd., Seoul, Korea.
authors.forename: Jiwon
authors.initials: J
authors.lastname: Ryu
authors.affiliation: Medical Imaging R&D Group, Health & Medical Equipment Business, Samsung Electronics Company, Ltd., Seoul, Korea.
authors.forename: Kyong Joon
authors.initials: KJ
authors.lastname: Lee
authors.affiliation: Medical Imaging R&D Group, Health & Medical Equipment Business, Samsung Electronics Company, Ltd., Seoul, Korea.
authors.forename: Jaeil
authors.initials: J
authors.lastname: Kim
authors.affiliation: Medical Imaging R&D Group, Health & Medical Equipment Business, Samsung Electronics Company, Ltd., Seoul, Korea.
authors.forename: Won-Chul
authors.initials: WC
authors.lastname: Bang
authors.affiliation: Infrastructure Technology Lab, R&D Center, Samsung Medison, Seoul, Korea.
authors.forename: Dong Kuk
authors.initials: DK
authors.lastname: Shin
authors.affiliation: Infrastructure Technology Lab, R&D Center, Samsung Medison, Seoul, Korea.
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Infrastructure Technology Lab, R&D Center, Samsung Medison, Seoul, Korea.
authors.forename: Dalkwon
authors.initials: D
authors.lastname: Koh
authors.affiliation: Infrastructure Technology Lab, R&D Center, Samsung Medison, Seoul, Korea.
authors.forename: Bong Koo
authors.initials: BK
authors.lastname: Seo
authors.affiliation: Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Seoul, Korea.
authors.forename: Kyunga
authors.initials: K
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results; D013997:Time Factors; D014463:Ultrasonography / Q000379:methods*
keywords: Biopsy; Fusion imaging; Magnetic resonance imaging; Radiofrequency ablation; Registration error; Registration time; Ultrasound