Vertebral fracture assessment: impact of instrument and reader

Many osteoporotic vertebral fractures are not clinically recognized but increase fracture risk. We hypothesized that a newer generation densitometer increases the number of evaluable vertebrae and vertebral fractures detected. We also explored the impact of reader experience on vertebral fracture assessment (VFA) interpretation. VFA images obtained using Prodigy and iDXA densitometers in 103 older adults were evaluated for vertebral visualization and fracture presence in the T4-L5 region. A "true" read for each densitometer was achieved by consensus. If readers disagreed, the evaluation of a third expert physician was taken as true. Main outcomes were evaluable vertebrae, vertebral fractures, and intrareader/interreader reproducibility. Using the "true" reads, 92% of vertebrae were visualized on iDXA and 76% on Prodigy. Numerically, more fractures were identified with iDXA; the "true" reads found 43 fractures on iDXA and 21 on Prodigy. The experienced reader had better intrareader and interreader reproducibility than the inexperienced reader when compared with the "true" read. Using the newer iDXA densitometer for VFA analysis improves vertebral body visualization and fracture detection. Training and experience enhance result reproducibility.