Discordance in diagnosis of osteoporosis using spine and hip bone densitometry.

Diagnostic discordance for osteoporosis is the observation that the T-score of a patient varies between skeletal sites, falling into 2 different diagnostic categories identified by the World Health Organization classification system. Densitometrists and clinicians should expect that at least 4 of every 10 patients tested by dual-energy X-ray absorptiometry (DXA) to demonstrate T-score discordance between spine and total hip measurement sites. T-score discordance can occur for a variety of reasons related to physiologic and pathologic patient factors and the performance or analysis of DXA itself.