# Artificial Intelligence–derived Measurements of Myosteatosis from Coronary Artery Calcium CT Scans to Predict COPD: The Multi-Ethnic Study of Atherosclerosis

## TL;DR

This study shows that measuring muscle fat in heart CT scans can predict COPD better than lung scans, using AI.

## Contribution

AI-derived myosteatosis measurements from CAC CT scans predict COPD more effectively than traditional emphysema biomarkers.

## Key findings

- Myosteatosis had a stronger unadjusted association with COPD than emphysema biomarkers.
- After adjustment, AI-measured myosteatosis remained a significant predictor of COPD.
- Findings suggest myosteatosis could be a novel biomarker for COPD risk assessment.

## Abstract

To evaluate the predictive value of myosteatosis as an opportunistic
finding in coronary artery calcium (CAC) CT scans for clinically
diagnosed chronic obstructive pulmonary disease (COPD) and compare it
with an artificial intelligence (AI)–measured biomarker of
emphysema derived from the same scans.

In this prospective study, baseline CAC CT scans and 20-year follow-up
data were analyzed. Myosteatosis was defined as the lowest quartile of
thoracic skeletal muscle mean attenuation (males < 33.5 HU,
females < 27.0 HU). The emphysema-like lung biomarker was
quantified as the percentage of lung voxels below −950 HU in CAC
CT scans. COPD was identified using the International
Classification of Diseases, Ninth Revision, Clinical
Modification, and International Classification of
Diseases, 10th Revision, Clinical Modification diagnostic
codes from hospital discharge records. Hazard ratios (HRs) for COPD were
calculated using proportional hazard regression models, comparing the
bottom versus top quartiles of myosteatosis and emphysema-like lung
measurements.

Among 5535 participants in the Multi-Ethnic Study of Atherosclerosis
(mean age ± SD, 62.2 years ± 10.3, 47.6% males), 396
(7.1%) were diagnosed with COPD over the 20-year follow-up period.
Myosteatosis showed a stronger association with COPD than emphysema
(unadjusted HRs, 5.98 [95% CI: 4.14, 8.63] and 2.12 [95% CI: 1.61,
2.78], respectively [P < .001]). After adjusting
for covariates (age, sex, smoking status, body mass index, race, asthma,
physical activity, inflammatory markers, and insulin resistance), the
HRs were reduced to 2.74 (95% CI: 1.81, 4.16) and 1.50 (95% CI: 1.12,
2.00), respectively (P = .02).

AI-measured myosteatosis in CAC CT scans strongly predicted future
diagnosed COPD independently of known risk factors.

Keywords: Applications-CT, Pulmonary, Thorax, Adipose Tissue
(Obesity Studies), Chronic Obstructive Pulmonary Disease, Metabolic
Disorders, Myosteatosis, Coronary Artery Calcium Scan, Emphysema,
AI-CVD

ClinicalTrials.gov: NCT00005487

Supplemental
material is available for this article.

© The Author(s) 2026. Published by the Radiological Society of
North America under a CC BY 4.0 license.