91.7%
Sensitivity at the lumbar spine
Correctly identifying those with osteoporosis
Back to Blog
Radiation-Free Imaging
The DEXA radiation-free alternative: the R.E.M.S. Bone Density Scan
If you've been told to avoid radiation but still need to know how your bones are doing, there is a test built for exactly that situation — and it measures more than density alone.
When “avoid radiation” and “check your bones” pull in different directions
DEXA is the standard bone density test, and for most people it does its job well. But it works by passing a low dose of X-ray through your body — which means there are situations where the test you need is the test you're advised to avoid.
That can feel like a dead end. It isn't. The reason to know your bone density doesn't disappear because X-rays aren't an option — the question just becomes what else can measure the same thing?
The answer is ultrasound.
How R.E.M.S. measures bone without radiation
R.E.M.S. stands for radiofrequency echographic multispectrometry. A technician passes an ultrasound probe over your lower back and hip — the lumbar spine and femoral neck. The system reads the radiofrequency signal that comes back and uses it to calculate bone mineral density.
If that sounds familiar, it should: it's the same family of technology as an obstetric ultrasound. Sound waves, not X-rays. No ionizing radiation at any point in the appointment, no contrast agent to drink or inject.
| DEXA | R.E.M.S. | |
|---|---|---|
| Method | Low-dose X-ray | Ultrasound |
| Radiation | Ionizing, small dose | None |
| Bone density (T-score) | Yes | Yes |
| Bone quality | Rarely, spine only | Fragility Score, spine & hip |
| Undressing | Often required | No — you stay clothed |
| Time in the room | 10–20 minutes | 10–15 minutes |
But is it as accurate as DEXA?
This is the right question to ask, because “safer” only matters if the result is trustworthy. In published research, it holds up:
91.5%
Sensitivity at the femoral neck
The same check at the hip
92.0%
Specificity at the spine
Correctly identifying those without it
88.8%
Agreement with DEXA at the spine
Same healthy / osteopenia / osteoporosis category
Those figures come from a multicenter trial of 1,914 postmenopausal women. The full study is in our research library, so your physician can read it directly.
Who is most likely to benefit
R.E.M.S. is a sensible option for anyone who needs a bone density scan, but it earns its place in four specific situations.
You're pregnant or breastfeeding
X-ray based tests are generally not recommended during pregnancy. Being radiation-free means bone density can still be assessed when it matters.
You need to be monitored over time
Bone health is watched across years, not measured once. A scan with no radiation exposure can be repeated as often as your physician recommends.
You're of childbearing age
Some physicians prefer to limit cumulative lifetime X-ray exposure where a radiation-free equivalent exists — particularly for younger women.
Arthritis is distorting your readings
Calcium buildup around the spine can inflate a DEXA reading. Ultrasound approaches the measurement differently, avoiding that particular distortion.
It also measures something DEXA doesn't
Bone density is only part of what determines whether a bone breaks. Two people can carry the same amount of mineral and have very different fracture risk, because the internal structure of the bone differs. Density tells you how much bone you have; it doesn't tell you how strong it is.
Every R.E.M.S. scan reports a Bone Fragility Score alongside the T-score — at both the spine and the hip. DEXA rarely assesses bone quality at all.
So the trade-off is better than it first appears. Choosing the radiation-free test isn't settling for a weaker measurement. You get a density reading that agrees with DEXA in the large majority of cases, plus a structural measurement DEXA usually doesn't provide — without the radiation.
What the visit is like
- You stay clothed the whole time — you lift your shirt only enough for the probe to reach your lower back and hip.
- There's no large machine to lie inside, and no need to stop any medications.
- The scan itself takes 10 to 15 minutes.
- Come with an empty stomach — we ask patients to arrive fasted so the images are as precise and clear as possible.
- Results are available the same day, and we send a copy to your referring physician the same day for their review.
This article isn't medical advice. Whether R.E.M.S. is right for you depends on your history, medications and why your physician wants a bone density test. Bring it up with them — and if they've ordered a DEXA, call us and we're glad to work with your doctor so they receive what they need.
Common questions
What is the radiation-free alternative to a DEXA scan?
The R.E.M.S. Bone Density Scan. It measures bone mineral density using ultrasound rather than X-rays, so there is no ionizing radiation at any point. It reports a T-score, a Z-score and a Bone Fragility Score from a single scan of the lumbar spine and femoral neck.
Is the R.E.M.S. scan as accurate as DEXA?
In published studies, yes. A multicenter trial of 1,914 postmenopausal women found the R.E.M.S. scan achieved sensitivity of 91.7% at the lumbar spine and 91.5% at the femoral neck, with specificity of 92.0% and 91.8%. Diagnostic agreement with DEXA — whether a patient was classified healthy, osteopenic or osteoporotic — was 88.8% at the spine and 88.2% at the hip.
Why would someone need to avoid DEXA?
Common reasons include pregnancy or breastfeeding, being of childbearing age, needing frequent repeat scans to monitor change over time, or having conditions such as arthritis that distort a DEXA reading. In any of these cases a radiation-free option is worth discussing with your physician.
Does R.E.M.S. use any radiation at all?
No. It uses ultrasound waves — the same underlying technology as an obstetric ultrasound. There is no X-ray, no ionizing radiation, and no injected or swallowed contrast agent at any point in the appointment.
Is the R.E.M.S. scan covered by insurance?
Coverage varies. Call us at 833-454-7263 with your insurance details before your appointment and we'll verify your specific situation for you.
How should I prepare, and when do I get results?
Come with an empty stomach — we ask patients to arrive fasted so the scan images are as precise and clear as possible. You stay clothed, and there's no need to stop any medications. Results are available the same day, and we send a copy to your referring physician the same day for their review.
Check your bones without the radiation
R.E.M.S. ultrasound bone density scanning at our Northvale, NJ center. No radiation, no undressing, results the same day.
Want the full comparison? REMS vs DEXA, side by side or see how the scan works.