Vascular Access の立体構造と狭窄を可視化する三次元評価技術の開発

抄録

An arteriovenous fistula (AVF) is widely used as the first choice for vascular access (VA) in maintenance hemodialysis patients. However, complications such as stenosis and occlusion have become significant issues due to the prolonged duration of dialysis treatment and the aging of patients, necessitating regular VA assessment and appropriate management. Ultrasonography is a simple, non-invasive method for VA evaluation;however, the images obtained are limited to two-dimensional information, making it difficult to accurately identify the spatial structure of the VA. In this study, we demonstrated the three-dimensional mapping of the VA using an existing ultrasound diagnostic system. We developed a system in which an ultrasound probe is mounted on a uniaxial movable stage, enabling the acquisition ultrasound cross-sectional images along the long axis of the AVF. The acquired images were processed using threshold-based image processing to extract the intravascular lumen region, which was then combined with stage coordinates to generate 3D point-cloud data. The 3D VA map constructed from measurements of AVF in maintenance hemodialysis patients revealed that the minimum cross-sectional area of the cephalic vein was 6.60mm² at z＝60mm. Furthermore, the histogram of differences between the reconstructed point cloud and the manual segmentation based theoretical point cloud showed mean ± standard deviation errors of －0.04 ± 0.61 mm, －0.04 ± 0.66 mm, and 0.01 ± 0.36 mm along the x, y, and z axes, respectively, indicating good agreement. This study demonstrates that 3D VA mapping using ultrasonography is an effective method for accurately visualizing and quantitatively assessing the spatial structure and stenosis of the VA.