Why Does Dose Matter Most in Paediatric Imaging?
Children's rapidly dividing cells are significantly more radiosensitive than adult tissue. The ICRP estimates that radiation risk for a child under ten may be two to three times higher than for an adult receiving the same dose. For conditions requiring repeated imaging, such as scoliosis monitoring, cumulative exposure becomes a genuine clinical concern. Low-dose modalities like EOS can reduce dose by about 90% compared with standard radiography.
Key Takeaways
- Children's tissue radiosensitivity makes dose optimisation a clinical priority, not just good practice.
- EOS delivers about 90% less radiation than a standard X-ray, around ten times less, while capturing full standing alignment.
- Standing, weight-bearing imaging removes the need for sedation and gives a true functional picture of alignment.
- A parent or carer can remain in the room throughout the scan.
- ScanAlign accepts direct referrals from paediatricians, orthopaedic surgeons and GPs.
Why is radiation dose more important in children than adults?
Children are not small adults. Their cells divide faster, their organs are still developing, and they have more remaining years in which a radiation-induced effect could, in theory, manifest. The International Commission on Radiological Protection (ICRP Publication 103, 2007) estimates that the lifetime attributable risk of cancer per unit dose for a young child may be two to three times that of a middle-aged adult.
This does not mean a single X-ray is dangerous. It means that when imaging is clinically justified, the ALARA principle (As Low As Reasonably Achievable) should guide modality choice, especially for conditions that require repeated exposure over months or years.
How does cumulative radiation exposure affect children with scoliosis?
Cumulative exposure is the real concern. A child diagnosed with scoliosis at age ten may undergo imaging every six to twelve months through adolescence. Using standard radiography, that could mean ten or more full-spine exposures before skeletal maturity.
Doody et al. (2000), in a large cohort study published in Spine, found a small but statistically significant increase in breast cancer mortality among women who had been repeatedly imaged for scoliosis during childhood and adolescence using conventional radiography. The study examined over 5,500 women and remains one of the most cited papers on this topic.
Deschênes et al. (2010), publishing in the European Spine Journal, demonstrated that EOS imaging reduced effective dose for paediatric scoliosis studies by a factor of approximately six to nine compared with computed radiography, depending on patient size and protocol.
The clinical takeaway is straightforward. When serial imaging is needed, choosing the lowest dose modality that still answers the clinical question is not just ALARA compliance. It is measurably better care.
Scoliosis, limb length and post-surgical follow-up often require imaging every 6 to 12 months.
Rapidly dividing cells in children are two to three times more radiosensitive than adult tissue (ICRP 103).
Low-dose EOS gives about 90% less radiation than a standard X-ray, around ten times less.
For more detail on dose reduction and the technology behind it, see EOS scan safety and radiation.
Why does standing imaging give a better clinical picture in children?
Standing, weight-bearing imaging captures the skeleton under the same gravitational load the child experiences every day. This matters because the body is a connected chain from feet to head. A problem in one area often makes another area compensate, and lying-down imaging can relax the muscles and hide alignment problems that only appear when standing.
For scoliosis, a supine MRI or lying-down X-ray may underestimate curve severity because gravity and muscle tone are removed from the equation. An EOS scan captures the full spine and lower limbs in a single standing exposure, giving you a true functional picture of alignment.
Weight-bearing alignment: Gravity loads the skeleton naturally, revealing true curve magnitude, pelvic obliquity and limb length differences as the child actually experiences them.
No sedation needed: The child simply stands still for a few seconds. A parent or carer stays in the room throughout.
Full kinetic chain in one image: Head to feet captured in a single low-dose exposure, so you see the whole compensation pattern at once.
Muscles relaxed: Lying down removes gravitational loading. Curves, tilts and compensations may appear less severe than they are functionally.
Sedation sometimes required: Young children who cannot stay still for an MRI or CT may need sedation, adding risk and logistical complexity.
Segmented imaging: Conventional X-rays often image the spine in sections, making full alignment assessment harder and requiring stitching.
You can read more about paediatric imaging at ScanAlign, including the child-friendly environment and what families can expect on the day.
How do I refer a child for an EOS scan?
ScanAlign accepts direct referrals from paediatricians, orthopaedic surgeons, physiotherapists and GPs. No intermediary is needed. The process is designed to be quick and straightforward.
If you have not referred before, register to refer patients. This takes a few minutes and only needs to be done once.
Complete the online referral form with the clinical question and relevant history. Specify the region of interest (full spine, lower limbs, or both).
The family attends 19 Harley Street. A parent or carer stays with the child throughout. The scan takes seconds, with no sedation required.
A detailed report with full alignment analysis is sent directly to you, the referring clinician, with images available on a secure platform.
Ready to refer a child? You can also explore what ScanAlign, low dose standing imaging offers across all age groups.
When should I choose EOS over MRI for a paediatric patient?
EOS and MRI answer different clinical questions. Choosing the right modality depends on what you need to see.
- Scoliosis monitoring and curve progression
- Limb length discrepancy assessment
- Lower limb alignment (valgus, varus, torsion)
- Post-surgical hardware review
- Pelvic obliquity and global balance
- Serial follow-up where cumulative dose is a concern
- Soft tissue, disc or nerve assessment
- Suspected spinal cord abnormalities
- Bone marrow pathology or infection
- Intra-articular soft tissue injuries
- Conditions requiring contrast enhancement
A note on MRI: EOS shows bones, joints and alignment under weight-bearing load. For soft tissue, discs or nerves, MRI is usually the better tool. The two are complementary, and in many paediatric MSK cases, both may be appropriate at different stages of assessment.
Frequently asked questions from referrers
Yes. EOS delivers about 90% less radiation than a standard X-ray, around ten times less. Published data from Deschênes et al. (2010) confirms dose reductions of six- to nine-fold for paediatric spine studies compared with computed radiography. For more detail, see our page on EOS scan safety and radiation.
Yes. If you have not referred before, you can register to refer patients online. It takes a few minutes and only needs to be done once.
Yes. A parent or carer remains in the room with the child throughout the scan. The child simply stands still for a few seconds. No sedation is needed.
ScanAlign can image children who are able to stand still for a few seconds. The minimum age depends on the child's ability to cooperate. There is no strict lower limit, but most referrals are for school-age children and adolescents. Adults are also scanned.
Reports include a full standing alignment analysis with calibrated measurements, annotated images, and a written commentary addressing the clinical question you specified in the referral. Images are available on a secure platform.
ScanAlign is a private, self-pay clinic. Pricing information is available on request and via the booking process. Families can also discuss costs during a free video consultation.
Yes. Scoliosis monitoring is one of the strongest clinical indications for EOS. The low dose means serial imaging over months or years carries a much lower cumulative exposure than conventional radiography. Standing images also give a functional, weight-bearing assessment of curve severity.
EOS and MRI are complementary, not interchangeable. EOS excels at bony alignment under load. MRI is better for soft tissue, discs, nerves, and marrow pathology. In many cases, both may be appropriate at different stages.
Children are usually asked to change into light, metal-free clothing. The team will explain what to wear when the appointment is confirmed. The aim is to keep the child comfortable and at ease.
ScanAlign is at 19 Harley Street, London, within The Harley Street Hospital. The clinic is easily accessible by public transport.
Refer a paediatric patient
If you have a young patient who needs low-dose standing alignment imaging, we are here to help.
Book a free video consultationSources
- International Commission on Radiological Protection. The 2007 Recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann ICRP. 2007;37(2-4):1-332.
- Deschênes S, Charron G, Beaudoin G, et al. Diagnostic imaging of spinal deformities: reducing patients radiation dose with a new slot-scanning X-ray imager. Eur Spine J. 2010;19(1):118-126.
- Doody MM, Lonstein JE, Stovall M, Hacker DG, Luckyanov N, Land CE. Breast cancer mortality after diagnostic radiography: findings from the U.S. Scoliosis Cohort Study. Spine. 2000;25(16):2052-2063.
Written by Abbas Dhami (Specialist Diagnostic Radiographer)
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.