Early detection of fractures with low-dose digital X-ray images in a pediatric trauma unit.

At the Red Cross Trauma Unit, we treat approximately 8,000 children with trauma annually. The major cause of severe, debilitating trauma and death is motor vehicle crashes (MVCs). Children injured in MVCs typically present with multiple injuries and diagnosis can be difficult, especially if a concomitant head injury is present. Fractures are easily missed in children, particular when clinical signs are absent or the patient is comatose, intubated, or sedated. Diagnostic errors in trauma departments are primarily attributable to inadequate radiographic practice, with missed fractures comprising the largest proportion of such errors. Radiography is not routinely performed on patients presenting with trauma. Decisions on whether to obtain radiographs and what parts of the anatomy to radiograph are based on departmental protocol, clinicians’ experience, patient history, and physical examination. Guly found that failure to perform radiography accounted for 13.4% of 953 diagnostic errors in 934 accident and emergency patients during a period of 4 years. In an earlier study, 55% of 39 fractures with delayed recognition were not radiographed at the time of admission to a trauma center. Routine, full-body radiography for trauma patients would eliminate some diagnostic errors and delays, but the risks of ionizing radiation, the time taken to obtain radiographs, and the costs involved prohibit such a practice in conventional screen-film radiography. The risks associated with ionizing radiation are higher in pediatric patients than in adults; bone marrow, the thyroid gland, the breast, and the lung have been reported to be especially sensitive to radiation. Infante-Rivard et al. found increased risk of leukemia with increased number of X-ray examinations and expressed concern that diagnostic radiation doses in children are not adequately controlled. A significant breast cancer mortality risk has been shown in scoliosis patients who had multiple diagnostic X-rays when they were young. Shu et al. reported increased risk of leukemia and childhood cancer with increased number of X-ray examinations. The evidence of increased cancer risk with increased radiation exposure in children highlights the importance of limiting the frequency and dose of radiographic examinations while maximizing the detection of injuries in the pediatric trauma setting. Computed radiography (CR) is replacing screen-film radiography. Dalla Palma et al. have shown that the total cost of CR is lower (by 20%) than that of conventional radiography when using 8 10 inch film as the output device for both the analog and the digital modalities. CR has the additional advantage that examinations are repeated less frequently because of overor underexposure, but the disadvantage that patients often receive higher doses of radiation per examination. Digital radiography (DR) has been shown to have equivalent image quality to CR, with reduced radiation dose, although Willis and Slovis have reported that overexposure is common in both CR and DR. CR is currently more popular than DR because of high costs, lack of portability, and fragility of detector hardware in the latter. Reiner et al. have reported that the cross-over point at which DR costs become justifiable in replacing CR, is at CR capacity utilization rates close to 80%. In this small study, in a trial comparing CR and full body DR in a pediatric trauma unit, we report three cases in which full-body low-dose digital radiographs obtained revealed fractures that would otherwise initially have been missed using the standard CR protocol.