Knowledge and use of Exposure Index (EI) in radiography in Norway and Singapore

Digital radiography's wide dynamic range, often leading radiographers to prefer overexposure to avoid noisy images, contributes to "dose creep." The Exposure Index (EI) was introduced as a feedback tool to balance image quality with radiation dose in line with ALARA. Understanding and proper use of the Exposure Index (EI) in digital radiography is vital for optimizing patient safety and image quality. This study aims to assess radiographers' knowledge, understanding, and application of EI in Norway and Singapore.

An online survey conducted in 2025 collected 238 responses in Norway and Singapore after institutional ethical exemption approval. A piloted questionnaire was administered via Qualtrics in Singapore and Nettskjema in Norway, and distributed through email, social media, and in-person outreach.

Respondents showed intermediate EI understanding, with difficulties differentiating EI from target EI (EIT) and recognising the importance of monitoring EI, particularly with vendor-specific scales. No significant correlations were found between demographics, perception, or clinical application, except for greater experience reduced vendor-specific confusion. Most agreed that EI support patient safety and applied EI primarily for chest imaging, with occasional overexposure more common in Singapore. EI-related image quality concerns varied by country: poor collimation and orthopedic appliances were most cited in Norway, while exposure field recognition was most cited in Singapore.

Collaborating with international vendors and educational institutions to standardise terminology and scales can reduce the knowledge gap, leading to safer imaging practices and better patient care. Revising workflows to integrate EI into clinical practice more consistently can address its underutilisation.

These findings inform the development of educational training and departmental protocols to improve understanding and correctly applying the EI for ensuring patient safety and improving imaging quality.