How do these two bone density technologies compare — and what does new research reveal about what's really driving your REMS results?
| Feature | DEXA Gold Standard | REMS (Echolight) |
|---|---|---|
| Technology | Low-dose X-ray directly measures bone mineral content | Ultrasound signals analyzed by proprietary algorithm against a demographic reference database |
| Radiation | Very low ~1 day of background | None Radiation-free |
| Reports | BMD, T-score, Z-score; optional TBS & VFA | BMD, T-score, Z-score, plus proprietary Fragility Score |
| Spinal Imaging | Yes VFA detects compression fractures | No No visual of the spine |
| Guideline Status | WHO standard for osteoporosis diagnosis | Not yet integrated into major guidelines |
| Physician Adoption | Universally accepted for treatment decisions | Most physicians will not prescribe based on REMS |
| Portability | Fixed installation; requires dedicated space | Portable Offices, clinics, mobile settings |
| Typical Cost | Often covered by Medicare / insurance | $300–$400+ out of pocket; limited coverage |
| Key Limitation | Affected by degenerative changes, scoliosis, aortic calcification | Output heavily driven by age & weight inputs (see below) |
A 2026 study in Osteoporosis International (Chan et al.) found that age and weight alone explain the vast majority of REMS output variance. The coloured bars show how much of each result is predicted by demographics alone.
Researchers scanned the same person's same hip multiple times, changing only the demographic data entered into the machine. The person's actual bone did not change.