Cambridge University Hospitals, NHS Foundation Trust and Fytas, Panagiotis and Breger, Anna
(2026).
XQA-Chest: Expert-Annotated Chest X-ray Dataset for Pathology Classification and Image Quality Assessment, 2026.
[Data Collection]. Colchester, Essex:
UK Data Service.
10.5255/UKDA-SN-858610
Data description (abstract)
Chest X-ray (CXR) machine learning relies heavily on automated evaluation using reference standards that aim to approximate clinical judgment. However, commonly used report-derived labels for pathology classification and generic image quality metrics for image reconstruction may not reliably reflect expert clinical assessment. XQA was collected to support systematic investigation of how evaluation choices affect model performance and ranking in both CXR pathology classification and image quality assessment (IQA).
XQA is split into two complementary components. XQA-RR supports research on pathology classification and contains paired expert image-based and report-derived labels for thoracic findings from a clinical cohort at Cambridge University Hospitals NHS Foundation Trust. XQA-IQA supports research on diagnostic image quality assessment and contains expert ratings of CXR image quality for reference images and degraded image variants.
Using XQA, we were able to evaluate supervised image classifiers, self-supervised models, and fine-tuned vision-language models, including ResNet, DenseNet, MedKLIP, GLoRIA, and ConVIRT. The results show that changing the evaluation reference can substantially affect both estimated model performance and model rankings. In parallel, the alignment of IQA measures with expert judgment depends strongly on the choice of measure, with commonly used metrics such as SSIM and PSNR often failing to reflect expert assessments of diagnostic usability.
The collection is intended to support research on clinical AI evaluation, CXR pathology classification, radiology report labelling, image quality assessment, and the clinical suitability of machine learning systems for CXR interpretation. If you use XQA, please cite the dataset repository and the accompanying paper:
Paper DOI: to be added once available.
| Data creators: |
|
| Contributors: |
| Name |
Affiliation |
ORCID (as URL) |
| Selby Ian |
Cambridge University Hospitals NHS Foundation Trust |
|
| Babar Judith |
Cambridge University Hospitals NHS Foundation Trust |
|
| Shahipasand Shahab |
Cambridge University Hospitals NHS Foundation Trust |
|
| Thavakumar Arthikkaa |
Cambridge University Hospitals NHS Foundation Trust |
|
| Chen John Li |
Cambridge University Hospitals NHS Foundation Trust |
|
| Sawer Alex |
Cambridge University Hospitals NHS Foundation Trust |
|
| Beckford Jake |
Cambridge University Hospitals NHS Foundation Trust |
|
|
| Sponsors: |
Innovative Medicines Initiative 2 Joint Undertaking (IMI2 JU), European Union’s Horizon 2020 research and innovation programme, EFPIA
|
| Grant reference: |
N/A - non-UKRI grant. EU/EFPIA Innovative Medicines Initiative 2 Joint Undertaking, DRAGON grant agreement No. 101005122
|
| Topic classification: |
Science and technology Health
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| Keywords: |
MEDICAL X-RAYS, HEALTH, MEDICAL DIAGNOSIS, SCIENCE AND TECHNOLOGY
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| Project title: |
DRAGON: Rapid and secure AI imaging based diagnosis, stratification, follow-up, and preparedness for coronavirus pandemics
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| Grant holders: |
Philippe Lambin, Universiteit Maastricht
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| Date published: |
26 Aug 2026 11:22
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| Last modified: |
26 Aug 2026 11:22
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| Geographical area: |
Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, United Kingdom |
| Country: |
United Kingdom |
| Data collection method: |
XQA was created from frontal chest X-ray studies and associated radiology reports from Cambridge University Hospitals NHS Foundation Trust. The studied population consists of patients who underwent chest X-ray imaging. The dataset was sampled and curated to support evaluation of chest X-ray machine learning systems across two tasks: pathology classification and image quality assessment. For XQA-RR, chest X-ray images and corresponding radiology reports were annotated to enable comparison between expert image-based labels and report-derived labels for thoracic findings. Image labels were assigned by clinical experts from the chest X-ray images, while report labels were derived from the corresponding radiology report text. For XQA-IQA, reference chest X-rays and synthetically degraded image variants were rated by expert readers for diagnostic image quality. |
| Observation unit: |
Text unit, Object |
| Kind of data: |
Numeric, Text, Still image |
| Type of data: |
Qualitative and mixed methods data |
| Resource language: |
English |
|
| Data sourcing, processing and preparation: |
The data collection is derived from existing clinical chest X-ray imaging and radiology report data from Cambridge University Hospitals NHS Foundation Trust. The CUH data were collected during routine clinical care and subsequently curated for research use. The collection was prepared to support two related evaluation settings: XQA-RR, focusing on pathology classification using image-based and report-derived reference labels, and XQA-IQA, focusing on diagnostic image quality assessment.
For XQA-RR, frontal chest X-ray images were paired with corresponding radiology reports. Expert image annotations were collected for thoracic findings, and report-derived labels were produced from the associated report text. For XQA-IQA, reference chest X-rays were used to generate degraded image variants, which were then rated by expert readers for diagnostic image quality. The dataset was quality controlled during curation and annotation, including checks of image/report pairing, annotation consistency, and suitability for the intended evaluation tasks.
Clinical data were anonymised or de-identified before release in accordance with the relevant governance, ethical, and data-sharing requirements. Direct patient identifiers were removed, and the released data are intended for research use only.
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| Rights owners: |
| Name |
Affiliation |
ORCID (as URL) |
| Cambridge University Hospitals NHS Foundation Trust |
|
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|
| Contact: |
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| Notes on access: |
The Data Collection is available for download to users registered with the UK Data Service. All requests are subject to the permission of the data owner or his/her nominee. Please email the contact person for this data collection to request permission to access the data, explaining your reason for wanting access to the data, then contact our Access Helpdesk.
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| Publisher: |
UK Data Service
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| Last modified: |
26 Aug 2026 11:22
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