Development of a method for quantitatively evaluating the flow of individual lymphatic vessels by photoacoustic imaging

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K18932
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56070:Plastic and reconstructive surgery-related
• Research Institution: Keio University
• Principal Investigator: Takemaru Masashi 慶應義塾大学, 医学部(信濃町), 助教 (80748749)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: リンパ浮腫

Outline of Final Research Achievements

Aiming at quantitative evaluation of lymphatic flow by photoacoustic imaging, we conducted a phantom test in which lymphatic vessels were reproduced with a silicon tube, and clinical trial of humans. In the phantom test, when the line image of the lumen was observed three-dimensionally, the cross section was often depicted in an arc shape instead of a circle shape. In imaging of humans, intermittent lymphatic flow in the collecting lymphatic vessels was observed in healthy subjects, and at that moment, the flow rate could be calculated. However, the values varied widely among lymphatic flows of the same lymphatic vessels; lymphatic vessels of the same subject; and subjects. The reproducibility of calculated values among measurers was so poor that they were not able to be used immediately as an index of lymphatic vessel function.

Free Research Field

形成外科学

Academic Significance and Societal Importance of the Research Achievements

本研究では、四肢のリンパ浮腫に対する外科的治療であるリンパ管細静脈吻合術において、より吻合に適する平滑筋の機能が十分に残存したリンパ管を同定するため、その機能を流量の指標で定量評価することを目指した。本研究を通じて1本1本のリンパ管の瞬間的な体積流量を算出することは可能であったが、リンパの流れには変動が大きく、流れ方に影響しうる条件も多様であり、計測のタイミングによって体積流量の値には大きなバラつきがあった。本指標をそのままリンパ管の機能を表すことは困難であるが、1本のリンパ管におけるリンパ流の状況を瞬間的にでも定量的に示したことには、学術的な意義があったものと考えられる。