DEXA Scan: Beyond Bone Density — Body Composition and Visceral Fat

Most people know DEXA scans for measuring bone density. But modern DEXA technology — like our Hologic Horizon Wi scanner — does much more. It's become the gold standard for body composition analysis, giving you data that scales, BMI calculators, and even blood tests simply cannot.

What Does DEXA Measure?

A single 10-minute DEXA scan provides three key measurements:

1. Bone Mineral Density (BMD) The original purpose of DEXA — measuring how dense and strong your bones are. Critical for detecting **osteoporosis** before a fracture occurs, monitoring bone loss over time, evaluating treatment effectiveness, and assessing fracture risk.

2. Body Fat Percentage DEXA is the **clinical gold standard** for body fat measurement. Unlike calipers, bioelectrical impedance scales, or BMI, DEXA offers accuracy within 1-2%, shows fat distribution by body region, tracks changes precisely over time, and distinguishes between subcutaneous and visceral fat.

3. Visceral Fat (VAT) This is the game-changer. Visceral adipose tissue (VAT) is the fat stored deep inside your abdomen, surrounding your organs. You can't see it in the mirror, and your weight or BMI won't reveal it.

Why visceral fat matters: - Strongly linked to Type 2 diabetes, heart disease, and stroke - Two people at the same weight can have dramatically different visceral fat levels - It's metabolically active — producing hormones and inflammatory chemicals - DEXA quantifies it precisely with a VAT score

Who Should Get a DEXA Scan?

For Bone Density - Women age 65+ and men age 70+ (routine screening) - Postmenopausal women under 65 with risk factors - Anyone with a fragility fracture - People on long-term corticosteroid therapy

For Body Composition - Athletes and fitness enthusiasts tracking training progress - Anyone on a weight loss program wanting precise measurements - People with metabolic syndrome or prediabetes - Post-bariatric surgery patients monitoring body changes

DEXA vs. Other Body Composition Methods

BMI: A simple height-to-weight ratio. Doesn't distinguish between muscle and fat. A muscular athlete and an obese individual can have the same BMI.

Smart scales (bioelectrical impedance): Accuracy varies wildly with hydration, recent exercise, and time of day. Typical error: 5-8%.

DEXA: Medical-grade precision. Measures bone, lean tissue, and fat separately. Maps distribution across your entire body. Reproducible and consistent.

What to Expect

1. **No fasting required** — eat and drink normally
2. **Wear comfortable clothing** — no metal zippers or buttons
3. **Lie flat on the scanner** — the arm passes over you slowly
4. **It takes about 10 minutes** — painless, no injections, minimal radiation
5. **Results are immediate** — your scan produces a detailed body composition report

The radiation dose is extremely low — about 1/10th of a chest X-ray.

Understanding Your Results

• **T-score** (bone density): Above -1.0 is normal; -1.0 to -2.5 is osteopenia; below -2.5 is osteoporosis
• **Body fat percentage**: 18-24% for men and 25-31% for women is generally healthy
• **Lean mass**: Total muscle and organ tissue by region
• **VAT mass**: Measured in grams — lower is better

Pro tip: Get a baseline scan, then repeat in 6-12 months to track changes. It's the most objective way to measure whether your diet and exercise program is actually working.

Schedule Your DEXA Scan

DEXA bone density scans are covered by most insurance plans for eligible patients. Body composition scans are available as a self-pay wellness service. Call (727) 398-5999 to schedule.