Low-dose chest CT (LDCT) performed for lung cancer screening found emphysema in 76.7% and coronary artery calcium in 65.1% of 2,361 participants in a New York screening program, and most of the emphysema had never been diagnosed. The retrospective study, published in September in the Journal of the American College of Radiology (JACR) by a Weill Cornell Medicine and NewYork-Presbyterian team, also shows the exam changed care: use of pulmonary services nearly doubled and cardiovascular care rose 20 percentage points in the following 12 months.
What the JACR study measured
The work, led by radiologist Lauren K. Groner with co-authors Puello, Onyebeke, Thomas, Marulanda Corzo, Andrade, Haile, Saleh, Pena, Green and Pinheiro, reviewed the baseline LDCT reports of every enrollee in the screening program of three NewYork-Presbyterian hospitals between 2015 and 2022. The cohort had a median age of 64 and was 52% male, the typical profile of current and former smokers eligible for screening.
The authors looked for two imaging biomarkers in the reports: emphysema, as a marker of chronic obstructive pulmonary disease (COPD), and coronary artery calcification (CAC), as a marker of cardiovascular disease. They then linked those findings to the medical record to see what happened in the 12 months after the scan, comparing care before and after with McNemar’s test, and used logistic regression to test associations with individual and ZIP-code-level social determinants of health.
The headline numbers, all from the paper:
- emphysema identified in 76.7% and CAC in 65.1% of participants;
- according to The Imaging Wire‘s coverage, 87% of patients with emphysema had no prior diagnosis;
- pulmonary care (spirometry, pulmonology referral, rehabilitation, tobacco cessation) rose from 24.4% to 45.8% after the scan;
- cardiovascular care rose from 42.6% to 63.3% (both p < 0.001);
- among those with CAC, there was more stress testing, medication adjustment, cardiac imaging and cardiology referral, although total “newly received cardiovascular care” did not differ from those without CAC.
Social determinants shaped emphysema, not calcium
The most original part of the study is the equity analysis. Living in a ZIP code with lower median household income raised the odds of emphysema by 57% (adjusted OR 1.57; 95% CI 1.22–2.02), and greater food insecurity raised them by 52% (OR 1.52; 1.20–1.94). For coronary calcium, no social determinant showed an association, which suggests tobacco exposure and poverty concentrate their damage in the lung while atherosclerosis tracks more evenly distributed drivers such as age, lipids and genetics.
After the scan, the picture became more nuanced. Among patients with emphysema, living in a high-poverty area was associated with more pulmonary care (OR 1.74; 1.25–2.42), possibly because those patients had more advanced, symptomatic disease. Among patients with CAC, lower ZIP-level educational attainment was associated with less cardiovascular care (OR 0.76; 0.60–0.98; p = 0.033). The authors use that finding to argue for standardized referral pathways that do not depend on a patient knowing to ask for an appointment.
What “coronary calcium” means on a non-gated CT
This is the technical point that deserves context. The classic Agatston score is measured on ECG-gated CT with thin slices and a dedicated protocol. Screening LDCT is acquired without gating, with thicker slices and a beating heart, so it does not yield a formal Agatston score. The calcifications are nonetheless visible, and established practice, endorsed by the Society of Cardiovascular Computed Tomography and the American College of Radiology, is to grade them visually on an ordinal scale (none, mild, moderate, severe) or by semiquantitative estimate. Multiple studies show that visual reading on non-gated CT predicts cardiovascular events comparably to the formal score, and Lung-RADS provides the “S” modifier precisely to flag clinically significant findings beyond the nodule.
Emphysema, in turn, appears on CT as low-attenuation areas (typically below -950 HU) and can be graded visually with the Fleischner Society classification (trace, mild, moderate, confluent, advanced destructive) or quantified by software. One caveat matters: emphysema on imaging is not synonymous with COPD, which requires spirometry showing airflow obstruction. That is why the study treats the finding as a biomarker that warrants work-up rather than a closed diagnosis, and it is exactly what the jump in spirometry reflects.
The logic is the same as the opportunistic screening we discussed when a lumbar X-ray revealed severe aortic calcification in dialysis patients: the exam was already done for another reason, the information is in the image, and wasting it is a choice.
No AI, just radiologists and a team
A detail highlighted by The Imaging Wire is that the study used no software tools to classify emphysema or calcium: no AI algorithms, no automated longitudinal tracking. All detection came from the radiologist’s structured report and the program’s navigation staff. That strengthens a practical argument: the “one-stop chest exam” does not depend on expensive technology but on standardized reporting, a protocol for communicating findings and a defined referral path.
At the same time, it is reasonable to expect AI to widen the gain. Automated CAC and emphysema quantification tools already hold regulatory clearance and can produce a reproducible number on every screening scan, cutting reader variability. Extracting more value from each CT is also the idea behind approaches such as radiomics AI that reads cancer risk in CT scans called normal. And follow-up failure remains the weak link: the case of the 8 mm nodule that was missed and became stage 4 cancer shows what happens when a finding is reported but nobody tracks it, and the same risk applies to emphysema and CAC.
Relevance for Brazil and Latin America
In Brazil, LDCT lung cancer screening is still in its infancy. There is no national program in the public SUS system, and existing initiatives are pilots or institutional projects, even though the Brazilian Thoracic Society and the Brazilian College of Radiology recommend the exam for the at-risk population. Adult smoking prevalence has fallen to roughly 9% according to the Vigitel survey, but the pool of former smokers with decades of exposure is large, and the PLATINO study estimated COPD at around 15% of São Paulo residents over 40, with heavy underdiagnosis.
In that setting, the “one exam, three diseases” argument carries economic weight: if each LDCT also delivers cardiovascular risk stratification and COPD detection, the cost-benefit of building a screening program improves, as discussed in our coverage of WCLC 2026 on scaling LDCT lung screening. And adherence, which we examined when we showed that uptake of CT lung screening is rising, gains an extra motivator for the patient.
Limitations
The design is retrospective and drawn from a single urban health system, with social determinants measured mostly by ZIP code rather than individual data. The 76.7% emphysema prevalence is high and probably reflects inclusion of any grade, including trace, in the report. The central point, acknowledged by the authors themselves, is that the study demonstrates more utilization of care, not better outcomes: it remains to be shown that the spirometry, statin or consultation triggered by LDCT reduces admissions or mortality. The full paper is available in JACR.
Source: The Imaging Wire | JACR (DOI 10.1016/j.jacr.2026.09.013)
