Opportunistic CT screening: getting more from every scan

Author:
Dr. Fabiana Andrade Melchiori, from Beth Israel Deaconess Medical Center

Computed tomography (CT) has always been one of the pillars of modern diagnostic imaging. It is usually ordered for a specific clinical question, read for that indication, and filed. Recently, the concept of opportunistic CT screening has emerged: the extraction of clinically meaningful secondary findings from already-performed routine CT exams, with no additional radiation exposure, additional imaging, or changes to the original scan protocol. Powered by artificial intelligence (AI), it represents a promising emerging development in CT practice.

When a patient undergoes a chest CT, that study can provide valuable information beyond its original purpose. Opportunistic screening leverages AI algorithms running in the background to automatically quantify findings from the same dataset, such as coronary artery calcium, cardiac chamber size, bone mineral density, and more.

The scale of the opportunity is significant. Approximately 19 million non-ECG-gated chest CTs are performed annually in the United States, compared to roughly 1 million dedicated ECG-gated scans to measure coronary artery calcium. Reporting opportunistic findings from these routine exams can enhance cardiovascular risk stratification without any additional radiation.

Recent evidence

A study published in Radiology Advances in March 2026 illustrates the clinical potential well. Researchers evaluated whether an AI tool could accurately measure total cardiac volume from routine non-ECG-gated, non-contrast chest CTs to identify cardiomegaly, a finding associated with heart failure, arrhythmias, and sudden cardiac death, using echocardiography as the reference standard. The results showed fair to good performance with high measurement repeatability, illustrating a potential role for automated cardiac volumetry as an objective opportunistic biomarker. The significance lies not just in the finding itself, but in the source: a routine scan, performed for an unrelated indication, yielding clinically relevant secondary cardiovascular information.

On the regulatory front, the FDA recently cleared an AI algorithm capable of performing 11 different opportunistic screening assessments on chest CTs ordered for any reason, automatically evaluating coronary artery calcium, aortic and cardiac chamber size, among other parameters.

Why it matters

AI can now perform these measurements automatically, reliably, and at scale without adding to radiologist workload. The growing emphasis on preventive medicine and early risk stratification aligns naturally with what opportunistic screening delivers. These quantitative outputs can flag early signs of coronary artery disease or heart failure, enabling a more personalized model of prevention based on each patient's specific risk profile supporting earlier treatment, primary and secondary prevention, and lifestyle modification.

There are, however, some practical considerations that need to be acknowledged. Incidental findings carry downstream implications: follow-up imaging, increased healthcare costs, patient anxiety, and the need for clear communication between radiology and referring clinicians. Thoughtful implementation, structured reporting, defined follow-up protocols, and multidisciplinary workflows will be essential as these tools enter routine practice.

Looking ahead

For the CT community, that represents both an opportunity and a responsibility: to advocate for responsible deployment of these tools, to help define best practices, and to ensure that the additional value extracted from every scan translates into better outcomes for patients.

References

1. Christopher M Fan, Angelo Scanio, Patricia Yokoo, Maya Wiessman, Michael Long, Matthew A Lewis, Yin Xi, Xinhui Duan, Roderick McColl, Suhny Abbara, Ronald Peshock, Fernando U Kay, Artificial intelligence-enabled cardiac volumetry for opportunistic screening of cardiomegaly on chest CT: clinical validation with echocardiography, Radiology Advances, Volume 3, Issue 2, March 2026, umag013, https://doi.org/10.1093/radadv/umag013

2. Foraker R, Sperling L, Bratzke L, et al. Opportunistic Detection of Coronary Artery Calcium on Noncardiac Chest Computed Tomography: An Emerging Tool for Cardiovascular Disease Prevention: A Scientific Statement From the American Heart Association. Circulation. 2025;152(19):e391-e401. doi:10.1161/CIR.0000000000001382

HeartLung Corporation. FDA Clears AI-CVD for Opportunistic Cardiothoracic Screening on Chest CT. Cardiovascular Business. January 15, 2026. https://cardiovascularbusiness.com/topics/artificial-intelligence/fda-clears-opportunistic-ai-detecting-cardiothoracic-issues-ct-scans