Diagnostic accuracy of DXA compared to conventional spine radiographs for the detection of vertebral fractures in children.
OBJECTIVES
In children, radiography is performed to diagnose vertebral fractures and dual energy x-ray absorptiometry (DXA) to assess bone density. In adults, DXA assesses both. We aimed to establish whether DXA can replace spine radiographs in assessment of paediatric vertebral fractures.


METHODS
Prospectively, lateral spine radiographs and lateral spine DXA of 250 children performed on the same day were independently scored by three radiologists using the simplified algorithm-based qualitative technique and blinded to results of the other modality. Consensus radiograph read and second read of 100 random images were performed. Diagnostic accuracy, inter/intraobserver and intermodality agreements, patient/carer experience and radiation dose were assessed.


RESULTS
Average sensitivity and specificity (95 % confidence interval) in diagnosing one or more vertebral fractures requiring treatment was 70 % (58-82 %) and 97 % (94-100 %) respectively for DXA and 74 % (55-93 %) and 96 % (95-98 %) for radiographs. Fleiss' kappa for interobserver and average kappa for intraobserver reliability were 0.371 and 0.631 respectively for DXA and 0.418 and 0.621 for radiographs. Average effective dose was 41.9 μSv for DXA and 232.7 μSv for radiographs. Image quality was similar.


CONCLUSION
Given comparable image quality and non-inferior diagnostic accuracy, lateral spine DXA should replace conventional radiographs for assessment of vertebral fractures in children.


KEY POINTS
• Vertebral fracture diagnostic accuracy of lateral spine DXA is non-inferior to radiographs. • The rate of unreadable vertebrae for DXA is lower than for radiographs. • Effective dose of DXA is significantly lower than radiographs. • Children prefer DXA to radiographs. • Given the above, DXA should replace radiographs for paediatric vertebral fracture assessment.
['Adiotomre|E|E|', 'Summers|L|L|', 'Allison|A|A|', 'Walters|S J|SJ|', 'Digby|M|M|', 'Broadley|P|P|', 'Lang|I|I|', 'Morrison|G|G|', 'Bishop|N|N|', 'Arundel|P|P|', 'Offiah|A C|AC|']
D015502:Absorptiometry, Photon D000293:Adolescent D000465:Algorithms D002648:Child D002675:Child, Preschool D005260:Female D006801:Humans D008297:Male D015588:Observer Variation D036301:Qualitative Research D011829:Radiation Dosage D011859:Radiography D015203:Reproducibility of Results D012680:Sensitivity and Specificity D016037:Single-Blind Method D016103:Spinal Fractures
Radiography Dual energy x-ray absorptiometry Interobserver variability Osteoporosis Spinal fractures