: Muscle Area by Computed Tomography (Cross-Sectional Muscle Area)
: This test uses computed tomography (CT) images to measure the cross-sectional area of a muscle, which helps assess muscle mass and detect muscle loss.
[": Muscle area on CT is an imaging-based measure of muscle mass, not a blood or body-fluid laboratory test."]
Key facts at a glance
- LOINC
- 98677-8
- Short code
- CMAP area AUC Muscle
- Synonyms
- CMAP area AUC Muscle
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- nerve-conduction
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
: What This Measure Represents
: Muscle area is calculated from a CT scan by outlining a muscle on a cross-sectional image and measuring the area it covers. It reflects how much muscle tissue is present at the level imaged and is often used to estimate overall muscle mass.
: How It Is Obtained
: The measurement comes from analyzing existing or newly acquired CT images, typically with software that traces muscle boundaries. No separate blood draw or specimen collection is involved; it depends entirely on the imaging study.
: What Results Can Indicate
: Lower muscle area can suggest reduced muscle mass, which may occur with aging, poor nutrition, prolonged illness, or certain chronic diseases. Higher area generally reflects greater muscle mass. Results are interpreted alongside other clinical information rather than on their own.
: Important Limitations
: Muscle area depends on the body level and imaging technique used, so results are best compared using consistent methods. It is an estimate of muscle quantity, not muscle strength or function, and should be interpreted by a clinician in context.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
: CT-derived muscle area is used mainly in research and specialized clinical settings to assess muscle mass, identify low muscle mass (sarcopenia), and support nutritional or rehabilitation planning. Because methods and measurement levels vary, results should be evaluated with standardized technique and in the context of the whole clinical picture.
Short name
: CT Muscle Area
Frequently asked questions
: Is this a blood test?
: What can affect the measured muscle area?
: Does a low muscle area always mean a health problem?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy