DEXA Body Composition Scan
Whole-body DEXA can estimate lean mass, fat distribution, visceral adipose tissue, and bone mineral density for body-composition questions. Bone diagnosis requires a different acquisition and read.
The Science
What This Test Measures
Dual-energy X-ray absorptiometry (DEXA) uses two low-energy X-ray beams to differentiate between bone, lean tissue, and fat tissue. A whole-body body-composition scan can estimate total and regional lean mass, total and regional fat, visceral adipose tissue, and whole-body bone mineral density.
Osteoporosis screening and diagnosis require a properly acquired and interpreted central DXA at the lumbar spine and hip. The 33% radius in selected circumstances can also be used. Interpretation follows population-appropriate T- and Z-score rules; a whole-body composition result is not a substitute.
Body-composition estimates can support cautious comparisons of muscle and fat over time. Scanner, software, positioning, hydration, and recent activity can all affect apparent change.
Interpretation
Measures a DEXA Can Provide
Whole-body bone mineral density as a composition output
Total and regional lean-mass estimates
Total and regional body-fat estimates
An estimate of visceral adipose tissue
Left-to-right differences that may merit context
A baseline for cautious comparison on the same equipment
Reading a Report
How to Think About It
01
Choose the measurement
Bone-density assessment and body-composition analysis can use the same technology but answer different questions.
02
Check comparability
Scanner, software, positioning, hydration, and recent exercise can affect body-composition comparisons over time.
03
Read the right metrics
T-scores, Z-scores, lean mass, fat distribution, and visceral-fat estimates each need their own context.
04
Use trends carefully
Meaningful change should exceed normal measurement noise and connect to a decision about bone, training, or nutrition.
Is This Right For You?
Who This Is For
You're working on body composition and want a cautious baseline
You want total and regional estimates of lean mass and fat
You want to compare body composition on the same equipment over time
You understand that hydration and recent exercise affect the result
You want an estimate of visceral adipose tissue with appropriate context
You know that bone-health indications require a separate central DXA evaluation
DEXA uses a low dose of ionizing radiation. Body-composition outputs vary by device and protocol. They do not diagnose osteoporosis or replace central-site imaging and clinical fracture-risk evaluation when indicated.