Is There a Weight or Size Limit for Scanning?
The EOS system at ScanAlign has a maximum patient weight of 250 kg (about 39 stone). You stand upright inside an open cabin roughly 130 cm wide and 175 cm deep, so there is no narrow tunnel to fit through. Most adults are comfortable during the scan, which lasts about 20 seconds.
Key takeaways
- Weight limit: 250 kg (approximately 39 stone).
- Cabin width: roughly 130 cm. No enclosed tunnel.
- You stand upright throughout. There is no table to lie on.
- About 90% less radiation than a standard X-ray, around ten times less.
- If you are unsure whether the scan suits you, a free video consultation confirms your suitability before you visit.
What are the exact weight and size limits for an EOS scan?
The EOS scanner at our Harley Street clinic has documented equipment specifications. Here are the numbers that matter.
| Specification | Detail |
|---|---|
| Maximum patient weight | 250 kg (approx. 39 st / 551 lb) |
| Cabin width (internal) | Approx. 130 cm |
| Cabin depth (internal) | Approx. 175 cm |
| Patient position | Standing upright, weight-bearing |
| Scan duration (full body) | Approximately 20 seconds |
| Radiation dose | About 90% less than a standard X-ray, around ten times less |
Because you stand inside an open cabin, there is no table weight limit to worry about and no enclosed bore to squeeze into. The cabin doors remain closed during the scan for shielding purposes, but the space inside is open and well lit.
Why does standing up during a scan matter for larger patients?
Standing up means your skeleton is under real weight-bearing load, exactly as it is in daily life. This matters for everyone, but it is especially relevant if you have a higher body mass.
When you lie on a table for a conventional X-ray, CT or MRI, your spine, pelvis and joints settle into a relaxed position. Muscles stop working. Alignment problems that cause pain while standing or walking may not show up at all. The EOS system captures your full posture under load, from head to feet, in one image.
For patients with a larger body type, lying-down scanners can also create practical difficulties. Standard X-ray tables typically have weight limits between 150 and 205 kg, and MRI bore diameters are usually 60 to 70 cm. Many people find the enclosed tunnel uncomfortable or simply cannot fit. Because the EOS cabin is open and you stand throughout, these issues do not apply.
You can read more about what to expect at an alignment assessment before your visit.
How does the EOS scan compare with MRI and CT for size restrictions?
Size and weight limits vary across imaging equipment. The table below gives a general comparison. Exact figures depend on the specific machine at each hospital or clinic.
| Factor | EOS (ScanAlign) | Standard MRI | Standard CT |
|---|---|---|---|
| Patient position | Standing | Lying down | Lying down |
| Weight limit | 250 kg | Typically 120 to 230 kg | Typically 200 to 300 kg |
| Opening / bore | Open cabin, ~130 cm wide | Usually 60 to 70 cm bore | Usually 70 to 80 cm bore |
| Enclosed tunnel? | No | Yes | Partially |
| Shows alignment under load? | Yes | No | No |
This is not a case of one scan being better across the board. Each tool answers a different question. ScanAlign, standing EOS imaging in Harley Street, focuses on skeletal alignment under load. MRI and CT serve different purposes, and your clinician may recommend more than one type of imaging.
How do I check whether this scan will work for me?
We confirm suitability before you travel to the clinic. Here is how the process works.
Free video consultation
You speak with our team from home. We ask about your height, weight and mobility so we can confirm the scanner suits you. No obligation.
Suitability confirmed
If everything looks good, we book your appointment. If we think the EOS scan is not the right tool for your situation, we will say so and suggest alternatives.
Arrive and scan
You walk into the open cabin, stand still for about 20 seconds, and the scan is done. No gowns unless needed. Privacy and dignity are a priority throughout.
Report and next steps
A specialist radiologist reviews your images and produces a detailed alignment report. You can share this with any treating clinician.
See who our scan is suitable for, or contact patient support if you have specific questions about access or comfort.
When MRI is the better choice. EOS imaging shows bones, joints and alignment under load. If your clinician needs to see soft tissue, discs or nerves, MRI is usually the better tool. The two scans answer different questions, and one does not replace the other.
Frequently asked questions
The maximum patient weight is 250 kg, which is approximately 39 stone or 551 lb.
The internal width is roughly 130 cm. It is an open, well-lit cabin, not a tunnel.
No. You stand upright throughout. The scan captures your skeleton under normal weight-bearing load, which is one of its main advantages.
In many cases, yes. The 250 kg weight limit and open cabin accommodate most patients. We confirm suitability during a free video consultation before you book.
If you have been unable to fit into an MRI bore, the open EOS cabin is a different experience. However, EOS and MRI answer different questions. EOS shows skeletal alignment under load, while MRI is needed for soft tissue, discs and nerves. If alignment imaging is what you need, EOS may be a good option.
About 90% less radiation than a standard X-ray, around ten times less.
No. ScanAlign is a private, self-pay clinic and you can refer yourself. A GP or specialist referral is welcome but not required.
The EOS system produces diagnostic-quality images across a wide range of body types. In some cases, higher body mass can slightly affect soft-tissue contrast, but the bony detail needed for alignment assessment is typically well preserved. Your suitability is confirmed before booking.
You can check suitability and book via a free video consultation. The consultation itself is free and without obligation.
Yes. The clinic is accessible and our team will assist you. You do need to be able to stand unaided for about 20 seconds during the scan itself. If you are unsure, mention this during your video consultation and we will advise.
Not sure if the scan suits you?
A free video consultation confirms your suitability before you visit. No obligation, no judgement.
Book a free video consultationWritten by Abbas Dhami (Specialist Diagnostic Radiographer)
Sources
- EOS imaging. Technical specifications, EOS system. EOS imaging (manufacturer documentation).
- Deschênes S, et al. Diagnostic imaging of spinal deformities: reducing patients' radiation dose with a new slot-scanning X-ray imager. Spine, 2010; 35(9): 989-994.
- NHS England. Guidance on diagnostic imaging services, 2023.
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.