A major international study coordinated by the International Atomic Energy Agency (IAEA) and Columbia University has revealed significant global variations in the radiation doses patients receive during diagnostic tests for coronary artery disease (CAD). Published in JAMA, the Journal of the American Medical Association, the study—the largest of its kind—analyzed data from over 19,000 patients across 101 countries, identifying that patients in low- and middle-income countries often receive significantly higher radiation doses than those in advanced economies for the same imaging tests.
While cardiac imaging remains essential for diagnosing CAD—the leading cause of death worldwide—the findings underscore an urgent need for standardized protocols, improved medical training, and updated equipment to ensure patient safety without compromising diagnostic quality. The IAEA emphasizes that these differences are "not inevitable," as the technology to reduce doses already exists but lacks consistent, equitable application.
Key Findings of the INCAPS4 Research Project
Geographic & Income-Based Disparity: Median radiation doses for coronary CT angiography and nuclear cardiology vary markedly based on a country's income level and available healthcare resources.
Technology-Driven Dose Reduction: Optimised protocols and newer imaging equipment are consistently associated with lower patient exposure and clearer diagnostic images.
Diagnostic Quality Maintenance: Authors stress that reducing radiation doses through optimized techniques does not lead to a reduction in diagnostic accuracy.
Critical Need for Specialised Training: High dose variations highlight the importance of training healthcare professionals in specific dose-reduction techniques and harmonized standards.
Investment in Modern Infrastructure: The study advocates for national policies that prioritize the procurement of updated imaging hardware to expand access to safe cardiac care.
What is the "INCAPS4" Study? The IAEA Noninvasive Cardiology Protocols Study (INCAPS4) is a coordinated research project designed to assess and optimize global radiation exposure from cardiac imaging. It provides the "Mechanical Fidelity" to track how medical resources are utilized across 742 centers, identifying technical gaps in protocol implementation. By establishing regional and global dose reference levels, INCAPS4 ensures "Implementation Fidelity" in radiation safety, providing a data-driven mandate for peer-to-peer knowledge sharing and updated clinical guidelines.
Policy Relevance
For India's healthcare system, the IAEA 2026 study marks a transition from "Access-First Imaging" to "Safety-Optimized Diagnostics," essential for managing the high burden of cardiovascular disease.
Operationalizing Dose Optimization: The findings provide a primary mechanic for the Atomic Energy Regulatory Board (AERB) to update national diagnostic reference levels (DRLs) for cardiac CT and nuclear scans.
Bypassing the "Income-Gap" in Safety: By identifying that dose reduction is possible with existing technology, the study acts as a strategic tool for Indian public hospitals to achieve global safety benchmarks through protocol refinement.
Mechanical Link to Quality Assurance: Implementing the INCAPS4 recommendations provides the "Technical Fidelity" needed to ensure that "Heal in India" initiatives attract global patients seeking world-class, low-dose diagnostic care.
Sovereign Healthcare Workforce Training: The study creates a mandate for the National Medical Commission to integrate dose-reduction techniques into the core curriculum for nuclear medicine and radiology professionals.
Relevant Question for Policy Stakeholders: What policy-level incentives are needed to encourage hospitals to replace legacy CT scanners with newer, low-dose technology to ensure implementation fidelityin patient safety?
Follow the full update here: IAEA: Variation in Radiation Doses from Cardiac Imaging
