Arjun is a Consultant Radiologist with a sub-specialty interest in cardiothoracic imaging at University College London Hospital and an Honorary Associate Professor at University College London. His research interests include implementation, standardisation, and quality assurance of lung cancer screening, integrating imaging biomarkers of cardiopulmonary health, and imaging of diffuse lung disease. He has been actively involved in several lung screening trials, beginning with the UK Lung Screening Pilot trial in 2011, and continuing through the SUMMIT Lung cancer screening study over the last six years. Arjun was appointed Joint Clinical Lead for the National Targeted Lung Health Checks programme in 2019, and the Royal College of Radiologists Travelling Professor of Thoracic Imaging in 2024. He currently co-chairs the British Thoracic Society Pulmonary Nodule Guideline Development Group.