"Doctor, can all these X-rays cause harm?" is an understandable question, especially when a child has already had multiple X-rays for a fracture, scoliosis, or a hip problem.
X-rays use ionizing radiation. Therefore, they are not exams to be performed without a clinical reason. In children, radiation protection requires particular attention because tissues are more radiosensitive and life expectancy is longer. [1][2]
However, this does not make an indicated X-ray an examination to be feared. In most pediatric orthopedic situations, the doses from plain X-rays are low, and the diagnostic benefit far outweighs the theoretical risk. [1][2][3]
The Decision Comes Before the Exam
The useful question is very practical: can this X-ray change the child's management?
It can help confirm a fracture, assess its displacement, check limb alignment, monitor scoliosis, study certain deformities, or verify the position of internal fixation devices. In these cases, the image can alter treatment, immobilization, surgical indication, or follow-up.
If, however, the examination does not add useful information, it should be avoided. This is the principle of justification upon which radiation protection is based. When the examination is necessary, the dose is then optimized based on age, body size, and anatomical region. [1][2]
Doses Are Not All Equal
Saying "they had X-rays" groups together very different examinations.
An X-ray of the hand, foot, or another peripheral segment generally involves a very low dose. A chest X-ray exposes more, but still remains within modest orders of magnitude. CT scans also use ionizing radiation and, depending on the region and protocol, can involve much higher doses compared to a plain X-ray. [3]
Even among CT scans, there are important differences: a highly targeted CT of a limb is not equivalent to a CT of the chest or abdomen.
Comparisons with natural radiation or air travel can help understand the orders of magnitude, but should be used with caution. The dose depends on the equipment, protocol, number of projections, the child's body size, and the area being studied. [3][4]
For this reason, there is no universal maximum number of X-rays a child "can have." It makes more sense to ensure that each examination has an indication and is performed with appropriate pediatric technique.
Why Children Require Dedicated Protocols
Using settings designed for an adult can unnecessarily increase a child's exposure. The FDA and IAEA recommend adapting technical parameters to the patient's size and the clinical question. [1][2]
In practice, this means limiting the field to the area to be studied, avoiding unnecessary projections, reducing repetitions, and obtaining a diagnostic image with the lowest reasonably achievable dose. This is the ALARA principle. [1][2][6]
Reducing the dose does not mean deliberately producing an insufficient image. If the X-ray does not answer the clinical question and must be repeated, radiation protection has failed.
Why Lead Aprons Are Sometimes No Longer Used
Many parents are surprised when shielding they remember as mandatory is not used.
With modern equipment, major medical physics organizations have progressively scaled back the routine use of gonadal and fetal shielding. Improperly placed shielding can cover part of the image or interfere with automatic exposure systems, increasing the risk of needing to repeat the examination. [7]
Protecting the child from radiation primarily depends on correct indication, collimation, selection of technical parameters, and the truly necessary number of images. [2][6]
X-ray, Ultrasound, MRI, and CT Answer Different Questions
Ultrasound and magnetic resonance imaging do not use ionizing radiation, but this does not automatically make them preferable.
Ultrasound is very useful in some pediatric situations, for example, in studying the newborn hip and certain soft tissues. MRI offers information that X-rays cannot provide, but it takes more time, and in young children, it can be difficult to perform without sedation.
CT can be crucial for some complex joint fractures, for surgical planning, or for a detailed three-dimensional evaluation. It should be used when that information is truly needed.
Choosing an examination therefore means choosing the most appropriate tool for the clinical question, not simply the one with "fewer rays."
If a Child Has Already Had Many X-rays
The number alone says little. A child with scoliosis, a complex fracture, or an orthopaedic condition during growth may need repeated check-ups for years. In these cases, avoiding a necessary examination can have more concrete consequences than the small radiological risk associated with a well-indicated X-ray.
It is, however, reasonable to ask whether some check-ups can be spaced out, whether all projections are necessary, or whether in a specific situation another method could provide the same information without radiation.
Pediatric radiation protection is not about performing fewer examinations at any cost. It is about performing those that are needed, when they are needed, with the technique appropriate for the child.
References
[1] U.S. Food & Drug Administration. Pediatric X-ray Imaging. https://www.fda.gov/radiation-emitting-products/medical-imaging/pediatric-x-ray-imaging
[2] International Atomic Energy Agency. Radiation protection of children in radiology. https://www.iaea.org/resources/rpop/health-professionals/radiology/children
[3] Radiological Society of North America / American College of Radiology. Radiation Dose from X-Ray and CT Exams. https://www.radiologyinfo.org/en/info/safety-xray
[4] UK Health Security Agency. Ionising radiation: dose comparisons. https://www.gov.uk/government/publications/ionising-radiation-dose-comparisons/ionising-radiation-dose-comparisons
[6] Image Gently Alliance. Digital Radiography Educational Materials — Back to Basics. https://www.imagegently.org/Procedures/Digital-Radiography/Educational-Materials
[7] American Association of Physicists in Medicine. AAPM Position Statement on the Use of Patient Gonadal and Fetal Shielding. 2019. https://www.aapm.org/org/policies/details.asp?id=468&type=PP
Disclaimer: content for general informational purposes only. It does not replace an individual medical evaluation.
