DOI: 10.34894/ykuebg
title: Rotterdam Artery-vein Segmentation Dataset
title: Multi-device set with semi-manual annotations corrected for connectivity

description: Dataset of color fundus images annotated at the Department of Ophthalmology, Erasmus MC, Rotterdam with semi-manual artery-vein segmentations. Segmentations were acquired by manual refinement of outputs from a vessel segmentation model trained on publicly-available datasets followed by coloring of the artery and vein trees in an overlapping manner. Annotations were checked for correct connectivity of artery and vein trees.
description: ## Image sources

The dataset consists of images from Dutch cohorts available to the Department of Ophthalmology at Erasmus Medical Center in Rotterdam; mainly the Rotterdam Study (RS). The RS is a prospective population-based cohort study of people living in Ommoord, a district of the city of Rotterdam (~\cite{Ikram2020}). The RS consists of four cohorts, all of which were used in this work. The minimum age of study participants varies between &gt;55 in the first cohort and &gt;40 in the fourth. Each cohort was followed for multiple rounds of follow-up examinations every 4 to 5 years. Most of the visits in the RS involved the capture of CFIs on both eyes. Due to the multi-decade span of the RS, multiple devices, capture conditions and fields (macula and disc centered) are present in the dataset.

In addition to the RS, we included images captured during the Randomized Controlled Trial for Age-Related Macular Degeneration (AMD-Life); which consisted of 150 patients aged 55–85 years imaged with a Topcon 3D OCT 2000-plus and Topcon TRC-50EX cameras. Images from the Dutch Myopia Study (MYST) which included younger subjects (mean (SD) age of 47.3 (12.9) years) were also used. These images were captured with a Topcon TRC-50EX.

## Sampling and Quality Control

We sampled CFIs at random from all available images. We included fundus images captured by OCT machines and older analog devices to improve diversity of devices in the dataset. Due to the much larger size of the Rotterdam Study compared to AMD-Life and MYST, we over-sampled CFIs from these sets to make up roughly 15% of the samples. We asked graders to exclude images for which they found the quality to be completely unusable for artery-vein segmentation due to overall low visibility of the vessels. However, we were intentionally inclusive regarding quality to encourage a more diverse and challenging development set. We included images considered unusable by quality estimation algorithms, under the consideration that although the general quality level of these images is poor, many contained clearly usable vascular information for measuring certain biomarkers.

## Annotation

We resolved connectivity issues at artery-vein crossings by annotating arteries and veins on separate layers. An interface was developed specifically for artery-vein segmentation to allow the graders to start from a vessel segmentation (no A/V distinction) and color arteries and veins into two independent masks or layers using drawing tools. A third layer - Unknown was added for vessels that could not be recognized as either. They were asked to color A/V crossings on both layers (overlapping). They were able to visualize and correct each layer independently, or all the same time. Another feature allowed them to visualize the connected components of each mask in different colors to easily find mistakes in connectivity. The entire process consisted in 1) correcting mistakes in the provided mask (vessel segmentation); 2) coloring the mask into A/V and unknown colors/layers; 3) verifying connected components on the A/V masks and filling any gaps.

## File structure

We provide three folders, all of which contain PNG files at 1024x1024 pixels with matching names.

rgb: preprocessed color fundus images in 1024 x 1024 resolution.
contrast_enhanced: Contrast-enhanced versions via unsharp masking to enhance visibility of the vessels.
av_masks: artery-vein segmentation masks. The masks are in the RGB channels. R = arteries, B = veins, G = unknown


## Metadata fields

- Cohort: Rotterdam Study subcohort | AMD-Life | MYST
- Device: manufacturer and model
- Patient age: in years at time of acquisition
- Patient sex: M / F

## Access

The data are sensitive since they involve personal information of patients. There are restrictions on use by commercial parties and on sharing openly, based on (inter)national laws and regulations and written informed consent. Therefore these data (and additional clinical data) are only available upon signing a Data Transfer Agreement (see Terms of Access).