The segmentation of hepatic vessels is crucial for liver surgical planning. It is also a challenging task because of its small diameter. Hepatic vessels are often captured in images of low contrast and resolution. Our research uses filter enhancement to improve their contrast, which helps with their detection and final segmentation. We have designed a specific fusion of the Ranking Orientation Responses of Path Operators (RORPO) enhancement filter with a raw image, and we have compared it with the fusion of different enhancement filters based on Hessian eigenvectors. Additionally, we have evaluated the 3D U-Net and 3D V-Net neural networks as segmentation architectures, and have selected 3D V-Net as a better segmentation architecture in combination with the vessel enhancement technique. Furthermore, to tackle the pixel imbalance between the liver (background) and vessels (foreground), we have examined several variants of the Dice Loss functions, and have selected the Weighted Dice Loss for its performance. We have used public 3D Image Reconstruction for Comparison of Algorithm Database (3D-IRCADb) dataset, in which we have manually improved upon the annotations of vessels, since the dataset has poor-quality annotations for certain patients. The experiments demonstrate that our method achieves a mean dice score of 76.2%, which outperforms other state-of-the-art techniques.

Society-level discourse on single-use plastics (SUPs) increases awareness of their negative environmental impacts and reduces their usage by environmentally aware individuals, firms, and governments. This article makes a unique and timely contribution to the literature by exploring why conference venues have not been proactive in reducing their usage of SUPs. Application of a questionnaire approach to collect primary data about venues' attitudes and practices towards their level and reduction in usage of SUPs reveals that although venues claim to be motivated to reduce delegates' use of SUPs, they state that excessive costs inhibit their ability to do so, and that legal and government regulations have the strongest influence on their use of SUPs. Our findings provide a frame of reference and an order of policy priority to ensure SUPs reduction by venues.