超音波診断用マイクロバブルの許容圧力の検討

Takuya Abe; 阿部拓也; Yutaka Fujii; 藤井豊; Haruo Hanawa; 塙晴雄; Keita Iguchi; 井口啓太; Kazuaki Takahashi; 高橋一哲; Yoshimitsu Takahashi; 高橋良光; Hiroaki Watanabe; 渡邊博昭; Kikuo Ikegami; 池上喜久夫; Katsuo Kubono; 久保野勝男; Daisuke Nagahama; 長濱大輔

doi:10.11272/jss.348

超音波診断用マイクロバブルの許容圧力の検討Analysis of Pressures at Which Ultrasonic Diagnostic Microbubbles Collapse

阿部拓也¹，藤井豊¹，塙晴雄²，井口啓太¹，高橋一哲¹，高橋良光³，渡邊博昭³，池上喜久夫¹，久保野勝男¹，長濱大輔¹Takuya Abe¹, Yutaka Fujii¹, Haruo Hanawa², Keita Iguchi¹, Kazuaki Takahashi¹, Yoshimitsu Takahashi³, Hiroaki Watanabe³, Kikuo Ikegami¹, Katsuo Kubono¹, Daisuke Nagahama¹

¹ 新潟医療福祉大学大学院保健学専攻医療技術安全管理学分野Department of Health Science, Field of Safety and Risk Management for Medical Technology, Niigata University of Health and Welfare Graduate School

² 新潟医療福祉大学健康科学部健康スポーツ学科Department of Health and Sports, Niigata University of Health and Welfare, Faculty of Health Sciences

³ 新潟医療福祉大学医療技術学部臨床技術学科Department of Clinical Engineering and Medical Technology, Niigata University of Health and Welfare, Faculty of Medical Technology

受付日：2021年2月19日Received: February 19, 2021

受理日：2021年10月20日Accepted: October 20, 2021

発行日：2022年2月1日Published: February 1, 2022

目的：超音波診断用造影剤Sonazoid®のペルフルブタンマイクロバブル（Perflubutane; PFB）は，圧力を加えることで容易に減少することが知られている．本研究では，PFBが造影効果を維持できる許容圧力を定量的に検討し，PFBの数・サイズを評価することで，造影剤投与時の明確な基準の確立を目的とする．

対象と方法：PFBを充填したシリンジをシリンジポンプに接続し，一定の速度で作動させることで500–1,000 mmHgの加圧を行った．加圧をしていないものをControlとして，加圧の差異による残存PFB数量・サイズを評価した．さらに，疑似ファントムを作製し，加圧後のPFB使用による造影効果を検討した．

結果と考察：Controlと比較し，500–800 mmHgで加圧することで20%程度のPFBが減少した．900 mmHg以上の加圧では減少率が約60%であり，特に造影効果に重要な役割を示す2–3 µmのサイズのPFB数が減少した．加えて，900 mmHg以上の加圧では疑似ファントムの造影剤投与部で低エコー領域を認めた．

結論：PFBは，加圧に比例して減少するわけではなく900 mmHg以上の加圧で有意に減少し，特に造影超音波検査に重要な役割を果たす2–3 µmのサイズのPFBが失われることで，造影効果が低下することを示した．

Purpose: It is known that the perflubutane microbubbles (PFBs) of Sonazoid®, a contrast medium used for the ultrasonic diagnosis of tumor lesions, disintegrate easily when pressure is applied. The purpose of this study was to quantitatively examine the pressure at which PFBs disintegrate and to evaluate the number and size of PFBs and their contrast effect to establish a standard when administering contrast media.

Subjects and Methods: Pressurization was performed by connecting a syringe containing Sonazoid®PFBs to a syringe pump, which was operated with a closed syringe port. A pressure sensor was attached to the syringe port to evaluate the changes in the properties and quantity of PFBs due to the differences in pressure. Furthermore, an original phantom was prepared, and the contrast effect of PFBs was examined after the pressurization.

Results and Discussion: The number of PFBs decreased with pressurization; it decreased by about 60% with pressures ≥900 mmHg. At 900–1,000 mmHg, PFBs that were ≥2–3 µm in size, which play an important role in the contrast effect, collapse, and a hypoechoic ultrasonic image was also displayed in the contrast medium administration part of the original phantom.

Conclusion: This study quantitatively examined the pressure at which PFBs can maintain the contrast effect. PFBs decreased when the pressure was ≥900 mmHg, and a pressure of 1,000 mmHg affected the contrast effect.

Key words: allowable pressure; contrast-enhanced ultrasonography; microbubbles; PFB; Sonazoid®

超音波検査技術

原著Original Article

超音波診断用マイクロバブルの許容圧力の検討Analysis of Pressures at Which Ultrasonic Diagnostic Microbubbles Collapse