Scott Skibo, MD, FCCP, Chief Medical Officer, Eon
Every low-dose CT ordered for lung cancer screening (LCS) captures the coronary arteries, and calcification in those arteries is visible on the same images. Coronary artery calcification (CAC) is common — roughly half of people have detectable calcifications — and appears regularly as an incidental finding on radiology reports.
For the patient, a single imaging study and a single appointment can therefore surface coronary risk alongside lung cancer risk, with no additional radiation.
While that cohort isn't an LCS population, the imaging mechanics are the same — coronary calcification shows up on a chest CT regardless of why it was ordered — so the finding is a reasonable indicator of how often clinically significant CAC turns up as background data on a scan. Across a screening population, that adds up to a considerable number of patients whose cardiac risk has been documented and left unaddressed.
The information is available to anyone who reads the chart, since the radiologist has already recorded it. Within a lung program, though, calcification carries much less urgency than a suspicious nodule, and it usually reads as background detail.
Screening reports already include a mechanism built for exactly this situation. Lung-RADS permits the reader to append an S modifier to the lung assessment category, marking a clinically significant finding unrelated to lung cancer. For CAC the trigger is moderate or severe disease on visual assessment: moderate or severe calcification generally corresponds to an Agatston score of at least 100, which is itself a guideline-based indication for statin therapy. The modifier exists to tell the ordering clinician that something in this study requires a management decision.
When radiologists apply it, clinicians respond. Statin initiation rises substantially compared with calcification described only in the body of the report, and downstream stress testing increases as well. A single character appended to a report measurably changes what happens to the patient.
Application varies widely, though. Studies of screening cohorts have found coronary calcification going unmentioned in roughly one in eight reports and underestimated in more than a quarter, and inter-reader concordance on S modifier reporting has been reported as low as 42%. In the same cohort referenced above, only 7% of patients with clinically actionable calcium received a referral for follow-up, and just 11% had started a statin a year after their scan.
Whether a patient's cardiac risk reaches a treating clinician depends partly on a reporting decision that differs between readers looking at comparable images. Responsibility for what happens next usually falls to primary care, where cardiac risk stratification competes with everything else in a fifteen-minute visit. In some cases it falls to no one at all.
Cardiovascular disease is the leading cause of death in the United States. The population coming in for annual low-dose CT consists largely of long-term smokers aged 50 and older, who carry elevated risk for coronary artery disease for many of the same reasons they qualify for lung screening. A single exam is therefore surfacing evidence of two of the leading causes of mortality in this country, though follow-up is considerably more reliable for one than for the other.
Consider a patient in his late sixties who has been screened annually for lung cancer since the early 2020s. His reports tracked a steady progression from year to year: plaque noted, then moderate calcification, then extensive diffuse disease. Each of those reports was accurate, and none of them prompted any action, because no structured pathway existed to move a cardiac finding out of a lung screening report and into cardiology's hands.
After that pathway is built, the same imaging produces a different outcome. The finding is flagged, his primary care physician is notified, and a cardiac workup is completed within weeks. He is now under active cardiology management, following several years in which escalating risk was visible in his chart.
In both cases the imaging is identical. The difference is in whether the surrounding system is built to recognize the finding and route it into the appropriate care pathway.
The remedy draws entirely on work that is already being done. It requires no new exam, no new program, and no additional demands on an imaging department that is already stretched thin, because the data has been collected by the time the report is signed and the gap opens after that point.
This is the specific gap Eon closes. Our platform reads the dictated report and captures moderate and severe coronary calcification wherever it appears in the text, whether or not the reader appended an S modifier. From there, Eon manages the full path: routing the finding to the right clinician, tracking the referral to completion, and keeping the patient visible for as long as a lifelong condition like CAC requires. Escalation no longer depends on a reporting convention that varies from reader to reader.
Lung cancer screening exams are collecting cardiac risk data at scale, on a population with a clear need for it. The remaining question for any health system running such a program is whether it has built something to recognize that data, act on it, and keep patients visible for as long as needed.
Learn more about Eon's Lung and Cardiovascular solutions
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Coronary artery calcium (CAC) is calcium deposited in the walls of the coronary arteries, a marker of coronary artery disease. It's common — roughly half of people have detectable calcification — and higher amounts correspond to higher cardiovascular risk. Guidelines use CAC scores, including an Agatston score of 100 or more, to guide decisions like starting statin therapy.
Yes. A low-dose CT ordered for lung cancer screening captures the coronary arteries in the same images, so calcification is often visible with no additional scan and no additional radiation. Radiologists frequently note it as an incidental finding, separate from the lung cancer assessment the scan was ordered for.
The S modifier is a code radiologists can append to a Lung-RADS score to flag a clinically significant finding unrelated to lung cancer, including moderate or severe coronary calcification. It's meant to alert the ordering clinician that the finding needs a management decision, but application varies widely between readers — inter-reader concordance has been reported as low as 42%.
Moderate or severe CAC calls for clinical follow-up, typically evaluation for statin therapy and possible cardiology referral. In practice, follow-up is inconsistent: in one study, only 7% of patients with clinically actionable calcium received a referral, and just 11% had started a statin a year after their scan.
Eon reads the dictated radiology report and captures moderate and severe coronary calcification wherever it appears in the text, whether or not the reader applied an S modifier. It then routes the finding to the right clinician, tracks the referral to completion, and keeps the patient visible for as long as follow-up is needed.
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