[Effect of exogenous fat on bone mineral density by DXA].
OBJECTIVE
To observe the effect of exogenous fat on the bone mineral density (BMD) of lumbar spine (LS) on a phantom measured by dual energy X-ray absorptiometry (DXA) Hologic QDR4500A.


METHODS
LS DXA scans were performed on an LS phantom, and were repeated when with lard packets (2 fresh lard packets and 2 refined lard packets, 5 cm or 10 cm thick).


RESULTS
After fresh lard packets were placed, only L1 BMD decreased significantly (P<0.05).When the 5 cm-thick refined lard packet was placed, BMD, bone mineral content (BMC),and bone area (BA) decreased obviously, but with the 10 cm-thick refined lard packet, BMD, BMC and BA decreased significantly (P<0.05 or P<0.01).


CONCLUSIONS
The exogenous fat may affect LS BMD of lumbar spine phantom by DXA Hologic QDR4500A, with significant decrease of the value,which may cause anomaly measurement of BMD in obese people and even misdiagnosis of osteoporosis.
Wu
Yuan
Y
Institute of Metabolism and Endocrinology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
Deng
Xiaoge
X
D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D001823:Body Composition; D015519:Bone Density; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008954:Models, Biological; D010024:Osteoporosis / Q000000981:diagnostic imaging