Radiofrequency
The raw ultrasound signal, before it's converted into a visual image. This is the data REMS analyzes — not the picture.
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REMS Technology
How REMS actually works
Radiofrequency Echographic Multi Spectrometry. That name is a mouthful — but each word in it describes something specific about how the technology measures your bones.
Decoding the name
Most explanations of REMS start with what it's not — no radiation, no X-rays. That's true and important. But it's more useful to understand what the technology actually does, because that's where the diagnostic value comes from.
The name breaks into three parts, and each one describes a real step in how the measurement works.
Echographic
From echo — it works by sending sound waves into tissue and analyzing what bounces back. The same physical principle as the ultrasound used in pregnancy.
Multi Spectrometry
The signal is analyzed across multiple frequency components simultaneously, rather than a single reading — which is what allows it to separate density information from structural information.
What the signal actually reveals
Four things happen in a single REMS scan.
It sends sound, not radiation
REMS transmits high-frequency ultrasound through the bone at the lumbar spine and femoral neck — the same two central sites DEXA measures. No X-ray, no ionizing radiation at any point.
It reads the raw signal, not just the picture
Most ultrasound produces an image a human interprets. REMS analyzes the unprocessed radiofrequency signal itself — the raw data before it becomes a picture. That signal carries structural information a visual reading wouldn't reveal.
It separates density from structure
From a single signal, the analysis derives two things: how much mineral is present (bone mineral density) and how the bone tissue is organized (the Fragility Score). DEXA measures the first; it rarely assesses the second.
It reports in the units your physician reads
Bone mineral density, T-score, and Z-score — the same parameters and the same scale as a DEXA report. It isn't a different kind of measurement; it's a different way of arriving at a comparable one.
The third point is the one that matters most. Separating density from structure in a single measurement is what allows REMS to report a Fragility Score alongside your T-score — two independent answers from one scan. We explain what each number means here.
The studies behind the technology
Two studies matter most. Neither is small, and neither was run by a single lab under ideal conditions.
The multicenter validation trial
1,914 postmenopausal women, 7 Italian centers. Each woman was scanned with both REMS and DEXA, and the two were compared on whether REMS correctly identified osteoporosis (sensitivity), correctly cleared patients who didn't have it (specificity), and agreed with DEXA's overall classification.
- Sensitivity 91.7% at the lumbar spine
- Specificity 92.0% at the lumbar spine
- Sensitivity 91.5% / specificity 91.8% at the femoral neck
- Diagnostic concordance with DEXA: 88.8% spine, 88.2% hip
Precision — how consistent repeated measurements are — was also better than the values typically reported in the literature for DEXA, which matters for anyone tracked over time.
The five-year prediction study
1,989 patients, followed for up to 5 years. This one tested the harder question: not whether REMS agrees with DEXA, but whether it predicts who actually fractures. The Fragility Score achieved accuracy (AUC 0.780–0.811) that was significantly higher than both the DEXA T-score and the REMS T-score (0.472–0.709) at every site tested — in both women and men.
The advantage held after adjusting for age and body mass index, meaning the Fragility Score is measuring something about bone itself rather than simply standing in for age.
And the regulatory piece. The REMS densitometer received FDA 510(k) clearance in October 2018 — a pathway that requires demonstrating equivalence to a legally marketed device, and confirming reliable comparative data exists.
All of the original papers — including the two described here — are available with full citations and PDFs on our research library page. That's the primary source; this article is the explanation.
Common questions
How does REMS actually measure bone?
REMS uses ultrasound — high-frequency sound waves — rather than X-rays. It transmits ultrasound energy through the bone and analyzes the radiofrequency signal that returns. That signal carries information about both how much mineral is present (density) and how the bone tissue is structured (quality).
What does the term 'radiofrequency echographic' mean?
Radiofrequency refers to the raw ultrasound signal before it's processed into a visual image. Echographic means it uses sound waves to examine tissue. REMS analyzes the unprocessed radiofrequency signal rather than just the resulting image, which is where it extracts information about bone quality that a visual reading wouldn't show.
Has REMS been validated in large studies?
Yes. The largest cited validation was a multicenter trial of 1,914 postmenopausal women across 7 Italian centers, which found 91.7% sensitivity and 92.0% specificity at the lumbar spine versus DXA. A separate five-year study of 1,989 patients found the REMS-derived Fragility Score predicted fractures more accurately than either the DEXA or REMS T-score.
Why does it matter that REMS measures bone quality?
Because bone density explains only part of fracture risk. Many people with dense bones still fracture, and many with thinner bones never do. Bone quality — the internal structure — is the other half of the picture, and DEXA rarely assesses it at all.
Is REMS a replacement for DEXA?
No. REMS is an alternative that reports the same measurements in the same units, and adds bone quality information on top. DEXA remains a mature clinical standard with decades of research behind it. The right choice depends on your situation — and for patients who need repeated monitoring or have arthritis, REMS is often the better fit.
Is the technology FDA-cleared?
Yes. The REMS densitometer received FDA 510(k) clearance in October 2018, confirming the existence of reliable data comparing REMS and DXA, and validating its diagnostic parameters: BMD, T-score, Z-score, and integrated FRAX fracture risk assessment.
See the technology for yourself
A REMS bone density scan takes about 15 minutes, uses no radiation, and reports both your bone density and your bone quality. Serving patients across New York and New Jersey.
Next: how REMS compares to DEXA or browse the original published papers.