title: Feasibility of Using Ultrasonic Nakagami Imaging for Monitoring Microwave-Induced Thermal Lesion in Ex Vivo Porcine Liver.
abstract: The feasibility of using ultrasonic Nakagami imaging to evaluate thermal lesions induced by microwave ablation (MWA) in ex vivo porcine liver was explored. Dynamic changes in echo amplitudes and Nakagami parameters in the region of the MWA-induced thermal lesion, as well as the contrast-to-noise ratio (CNR) between the MWA-induced thermal lesion and the surrounding normal tissue, were calculated simultaneously during the MWA procedure. After MWA exposure, a bright hyper-echoic region appeared in ultrasonic B-mode and Nakagami parameter images as an indicator of the thermal lesion. Mean values of the Nakagami parameter in the thermal lesion region increased to 0.58, 0.71 and 0.91 after 1, 3 and 5 min of MVA. There were no significant differences in envelope amplitudes in the thermal lesion region among ultrasonic B-mode images obtained after different durations of MWA. Unlike ultrasonic B-mode images, Nakagami images were less affected by the shadow effect in monitoring of MWA exposure, and a fairly complete hyper-echoic region was observed in the Nakagami image. The mean value of the Nakagami parameter increased from approximately 0.47 to 0.82 during MWA exposure. At the end of the postablation stage, the mean value of the Nakagami parameter decreased to 0.55 and was higher than that before MWA exposure. CNR values calculated for Nakagami parameter images increased from 0.13 to approximately 0.61 during MWA and then decreased to 0.26 at the end of the post-ablation stage. The corresponding CNR values calculated for ultrasonic B-mode images were 0.24, 0.42 and 0.17. This preliminary study on ex vivo porcine liver suggested that Nakagami imaging have potential use in evaluating the formation of MWA-induced thermal lesions. Further in vivo studies are needed to evaluate the potential application.
authors.affiliation: Key Laboratory of Biomedical Information Engineering, Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Siyuan
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Biomedical Information Engineering, Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Yuqiang
authors.initials: Y
authors.lastname: Han
authors.affiliation: Key Laboratory of Biomedical Information Engineering, Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Xingguang
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Biomedical Information Engineering, Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Shaoqiang
authors.initials: S
authors.lastname: Shang
authors.affiliation: Key Laboratory of Biomedical Information Engineering, Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Guojing
authors.initials: G
authors.lastname: Huang
authors.affiliation: Key Laboratory of Biomedical Information Engineering, Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Radiology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Niu
authors.affiliation: Key Laboratory of Biomedical Information Engineering, Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Supin
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Xijing
authors.initials: X
authors.lastname: He
authors.affiliation: Key Laboratory of Biomedical Information Engineering, Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China. Electronic address: mxwan@mail.xjtu.edu.cn.
authors.forename: Mingxi
authors.initials: M
authors.lastname: Wan
mesh_terms: D055011:Ablation Techniques / Q000379:methods*; D000818:Animals; D005240:Feasibility Studies; D008099:Liver / Q000000981:diagnostic imaging* / Q000601:surgery*; D008872:Microwaves; D023421:Models, Animal; D013552:Swine; D014463:Ultrasonography / Q000379:methods*
keywords: Microwave ablation; Monitor; Nakagami; Ultrasound imaging