Protocol for Multi-modality MEdical imaging sTudy bAsed on KaiLuan Study (META-KLS): rationale, design and database building

Introduction Multi-modality medical imaging study, especially brain MRI, greatly facilitates the research on subclinical brain disease. However, there is still a lack of such studies with a wider age span of participants. The Multi-modality MEdical imaging sTudy bAsed on KaiLuan Study (META-KLS) was designed to address this issue with a large sample size population.Methods and analysis We aim to enrol at least 1000 subjects in META-KLS. All the participants without contraindications will perform multi-modality medical imaging, including brain MRI, retinal fundus photograph, fundus optical coherence tomography (OCT) and ultrasonography of the internal carotid artery (ICA) every 2-4 years. The acquired medical imaging will be further processed with a standardised and validated workflow. The clinical data at baseline and follow-up will be collected from the KaiLuan Study. The associations between multiple risk factors and subclinical brain disease are able to be fully investigated. Researches based on META-KLS will provide a series of state-of-the-art evidence for the prevention of neurological diseases and common chronic diseases.Ethics and dissemination The Kailuan Study and META-KLS have been approved by the Medical Ethics Committee of Kailuan General Hospital (IRB number: 2008 No. 1 and 2021002, respectively). Written informed consent will be acquired from each participant. Results are expected to be published in professional peer-reviewed journals beginning in 2023.