Automated Muscle Measurement on Chest CT Predicts All-Cause Mortality in Older Adults From the National Lung Screening Trial.

Authors

Lenchik L, Barnard R, Boutin RD, Kritchevsky SB, Chen H, Tan J, Cawthon PM, Weaver AA, Hsu FC

Affiliations

• Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina.
• Department of Biostatistics and Data Science, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina.
• Department of Radiology, Stanford University Medical Center, California.
• Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina.
• California Pacific Medical Center Research Institute, San Francisco.
• Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, North Carolina.

Abstract

BACKGROUND: Muscle metrics derived from CT are associated with adverse health events in older persons, but obtaining these metrics using current methods is not practical for large datasets. We developed a fully-automated method for muscle measurement on CT images. This study aimed to determine the relationship between muscle measurements on CT with survival in a large multicenter trial of older adults.

METHODS: The relationship between baseline paraspinous skeletal muscle area (SMA) and skeletal muscle density (SMD) and survival over 6 years was determined in 6803 men and 4558 women (baseline age: 60-69 years) in the National Lung Screening Trial (NLST). The automated machine learning pipeline selected appropriate CT series, chose a single image at T12, and segmented left paraspinous muscle, recording cross-sectional area and density. Associations between SMA and SMD with all-cause mortality were determined using sex-stratified Cox proportional hazards models, adjusted for age, race, height, weight, pack-years of smoking, and presence of diabetes, chronic lung disease, cardiovascular disease, and cancer at enrollment.

RESULTS: After a mean 6.44 ± 1.06 years of follow-up, 635 (9.33%) men and 265 (5.81%) women died. In men, higher SMA and SMD were associated with a lower risk of all-cause mortality, in fully adjusted models. A one-unit standard deviation increase was associated with a hazard ratio (HR)=0.85 (95%CI=0.79,0.91;p<0.001) for SMA and HR=0.91 (95%CI=0.84,0.98;p=0.012) for SMD. In women, the associations did not reach significance.

CONCLUSION: Higher paraspinous SMA and SMD, automatically derived from CT exams, were associated with better survival in a large multicenter cohort of community-dwelling older men.