Published papers

Background Lymphaticovenular anastomosis (LVA) is a minimally invasive surgical procedure used to treat lymphedema. Volumetric measurements and quality-of-life assessments are of-ten performed to assess the effectiveness of LVA, but there is no method that provides information regarding postoperative morphological changes in lymphatic vessels and veins after LVA. Photoacoustic lymphangiography (PAL) is an optical imaging technique that visualizes the distribution of light-absorbing molecules, such as hemoglobin or indocyanine green (ICG), and provides three-dimensional images of superficial lymphatic vessels and the venous system simultaneously. In this study, we performed PAL in lymphedema patients before and after LVA and compared the images to evaluate the effect of LVA. Methods PAL was performed using the PAI-05 system in three patients (one man, two women) with lymphedema, including one primary case and two secondary cases, before LVA. ICG fluorescence lymphography was performed in all cases before PAL. Follow-up PAL was performed between 5 days and 5 months after LVA. Results PAL enabled the simultaneous visualization of clear lymphatic vessels that could not be accurately seen with ICG fluorescence lymphography and veins. We were also able to observe and analyze morphological changes such as the width and the number of lymphatic vessels and veins during the follow-up PAL after LVA. Conclusions By comparing preoperative and postoperative PAL images, it was possible to analyze the morphological changes in lymphatic vessels and veins that occurred after LVA. Our study suggests that PAL would be useful when assessing the effect of LVA surgery.

手術をビデオ撮影してモニターで表示することの有用性は以前から認識されている.多くの手術室には,すでに固定式の術野カメラが設置されている.しかし,これらカメラでは外科医の頭部や手によって術野の遮蔽が生じ,Open Surgeryの動画活用が進まない一因となっていた.この課題を解決するために,多視点カメラで術野を撮影するという手法がある.本論文では,多視点カメラとして横1列のカメラアレイと,マルチカメラ搭載型無影灯による撮影手法を提案する.多視点の映像には画像検出を適用し,認識された術野領域の大小によってカメラを自動で選択することで,遮蔽のない術野映像を表示し続ける.ただし頻繁なカメラの切り替えは動画の視聴品質(Quality of View,QoV)を損なうので,術野の表示とQoVを両立するカメラスケジューリングを適用する.また本提案手法を実際の手術に適用し,その有用性を検証する.(著者抄録)