Scaling up fine-grained intracranial vessel annotations in computed tomography angiography

2026-06-19

AI Summary

This work addresses the limitation of existing cerebrovascular segmentation datasets, which often omit small arteries and lack comprehensive fine-grained annotations. To overcome this, the authors introduce SemanticVessel, a novel dataset derived from dynamic 4D-CTA scans. Initial arteriovenous segmentations are generated using an intensity-guided region-growing algorithm and subsequently refined by radiology experts who meticulously label 20 distinct arterial structures. Notably, small arteries are unified into a new “generic artery” category to enhance anatomical completeness. A multi-phase label propagation strategy enables efficient reuse of annotations across temporal phases, substantially expanding the volume of high-quality labels without additional manual effort. Incorporating the generic artery class consistently improves model performance across all fine-grained vascular segmentation tasks. The code, annotation tools, and trained model weights are publicly released.

Abstract

In this work, we present SemanticVessel, a dataset for fine-grained brain vessel segmentation in computed tomography angiography scans. Based on the detailed contrast provided by dynamic 4D-CTA scans, we generate segmentation traces for arteries and veins. We then use intensity-guided region growing to obtain segmentations of the majority of vascular territories in the human brain, which are refined and annotated with 20 unique arterial classes by an expert radiologist. Unlike existing datasets, where minor arteries are discarded as background content, we merge these minor arteries into a generic arterial class. Due to the multiple-phase acquisition of dynamic 4D-CTA, labels for a single phase can be re-used for other phases in the same series, greatly increasing the size of our dataset with no additional annotation cost. The results show that models trained with the additional generic artery class produce better fine-grained segmentations across the board. We will make our code, annotation GUI, and model weights available to the scientific community. Code, weights, and data will be made available on https://github.com/alceballosa/robust-vessel-segmentation

Problem

• fine-grained vessel segmentation
• intracranial vessels
• computed tomography angiography
• minor arteries
• 4D-CTA

Innovation

• fine-grained vessel segmentation
• dynamic 4D-CTA
• generic arterial class
• intensity-guided region growing
• multi-phase label propagation