Quantifying Sarcopenia Reference Values Using Lumbar and Thoracic Muscle Areas in a Healthy Population

Area of Science:

• Gerontology
• Radiology
• Anatomy

Background:

• Sarcopenia, the age-related loss of muscle mass and function, poses a significant health concern.
• Accurate quantification of muscle mass via CT scans is vital, yet reference data in healthy US populations is scarce.

Purpose of the Study:

• To establish reference measurements for skeletal muscle cross-sectional area (CSA) in a healthy US population.
• To determine the optimal Hounsfield Unit (HU) range and assess the impact of contrast on muscle CSA measurements.

Main Methods:

• Utilized two-phase CT scans from 604 healthy kidney donors (age 18-40).
• Quantified thoracic and lumbar muscle CSA, including height-indexed measurements.
• Analyzed the effects of contrast and various HU ranges on CSA values.

Main Results:

• Provided reference CSA (cm²) and height-indexed CSA (cm²/m²) cutoffs for multiple muscle groups (T12, L3, L4) in males and females.
• Established an optimal HU range of -29 to 150 for muscle quantification.
• Confirmed no significant difference in CSA measurements between contrast-enhanced and non-contrast CT scans within the optimal HU range.

Conclusions:

• Quantified essential reference values for lumbar and thoracic muscle CSA in a healthy US cohort.
• Defined the impact of IV contrast and HU ranges on muscle measurements.
• Facilitates the clinical utility of existing CT scans for sarcopenia assessment.