What are the risks of computed tomography (CT) scans in pediatric patients and how can they be minimized?

Risks of CT Scans in Pediatric Patients

Children are at significantly higher risk than adults from CT radiation exposure due to their actively dividing cells, increased organ radiosensitivity, and longer life expectancy for radiation-induced cancers to develop, making strict adherence to dose optimization protocols essential. 1

Primary Radiation-Related Risks

Cancer Risk

• The pediatric brain is more sensitive to ionizing radiation than the adult brain because of a larger proportion of actively dividing cells and the longer life span available for radiation-induced tumor development 1
• Recent epidemiological studies evaluating childhood CT exposure have demonstrated an increased lifetime relative risk of cancer, though the magnitude of risk from a single head CT study is expected to be very low 1
• Children receive larger organ-specific radiation doses compared to adults due to their smaller body size, compounding their inherent increased susceptibility to developing malignancy 1

Other Radiation Effects

• Radiation exposure to the lens of the eye from head CT increases the risk for developing cataracts later in life 1
• The cumulative radiation burden is particularly concerning for children with chronic conditions requiring repeated imaging over their lifetime 1

Non-Radiation Related Risks

Procedural and Diagnostic Risks

• False-positive and incidental findings can lead to downstream testing that compounds the original risks 1
• Increased ED length of stay while awaiting imaging 1
• Potential need for sedation, particularly for younger children 1
• Risk of requiring repeat studies if not optimally performed initially, multiplying all associated risks 1
• Transport away from the ED to imaging facilities may delay other interventions 1

Healthcare System Impact

• Overall increased healthcare costs from both the imaging itself and downstream testing 1

Risk Minimization Strategies

Institutional Requirements

Weight- and size-based CT parameters must be adjusted for pediatric patients following the ALARA ("as low as reasonably achievable") principle 1

• Implement pediatric-specific, reduced-dose CT protocols at all facilities imaging children 1, 2
• Nearly 25% of EDs lack reduced-dose radiation protocols for pediatric CT, representing a critical gap that must be addressed 1
• Technical innovations including adaptive statistical iterative reconstruction tools have contributed to radiation dose reductions of 20% in trauma patients 1
• Ultra-low-dose CT protocols specific to certain indications (such as ventricular shunt evaluation) can reduce radiation exposure without compromising image quality 1

Clinical Decision-Making

Use validated clinical decision rules to identify children at very low risk who can safely avoid CT imaging 1, 2

• The PECARN (Pediatric Emergency Care Applied Research Network) rule identifies children at very low risk for clinically important traumatic brain injury who can safely avoid CT 1, 2
• In the PECARN study of 42,412 patients, only 0.9% had clinically important TBI, demonstrating that most children do not require CT 1
• Clinical observation before CT decision-making is an effective strategy for reducing unnecessary radiation exposure in children with mild TBI (GCS 14-15) 1, 2
• Every additional hour of ED observation time is associated with a commensurate decrease in CT utilization without delay in diagnosis of significant injuries 1, 2

Alternative Imaging Modalities

Prioritize ultrasonography as the first-line imaging modality whenever clinically appropriate, as it involves no ionizing radiation 1

• Pediatric patients' small body habitus and less subcutaneous fat make ultrasonography particularly effective for many indications 1
• Ultrasonography is recommended as first-line imaging for appendicitis evaluation 1
• For suspected neck infections, ultrasonography should be considered before CT when appropriate 1
• Lower extremity Doppler ultrasound can serve as first-line testing for suspected pulmonary embolism or deep vein thrombosis 1

Consider MRI when cross-sectional imaging is required and clinical stability permits 1

• Rapid MRI protocols with abbreviated sequences have decreased study duration and increased feasibility in emergency settings 1
• MRI is preferred over CT for follow-up imaging in pediatric patients when cross-sectional imaging is needed 1
• For pregnant females, MRCP should be the diagnostic modality of choice for new-onset biliary symptoms 1
• Rapid MRI should be considered for ventricular shunt malfunction evaluation to reduce lifetime radiation exposure 1

Specific Clinical Scenarios

Avoid routine "pan-scan" whole-body CT in pediatric trauma patients; use selective region-specific scanning based on clinical prediction models 1

• Cervical spine CT and chest CT are seldom indicated as screening studies in pediatric patients 1
• Evidence-based clinical guidelines should be used to avoid CT in patients at very low risk for clinically important injuries 1
• Imaging decisions should identify clinically-important injuries rather than just radiographically apparent ones (except in child abuse cases where all injuries require forensic documentation) 1

Critical Pitfalls to Avoid

• Do not apply the PECARN head injury rule to children with suspected abuse, as this population was excluded from the validation study 1
• Avoid obtaining advanced imaging at referring centers for injured patients who require transfer to pediatric trauma centers unless performed in consultation with the receiving facility 1
• Do not compromise diagnostic quality in pursuit of dose reduction—optimization means achieving appropriate image quality at the lowest achievable dose, not dose reduction at any cost 1
• Ensure consultation with pediatric radiologists when available to minimize missed findings and prevent misinterpretation of normal developmental anatomy 1