Quantitative dual-energy radiographic absorptiometry of the lumbar spine: in vivo comparison with dual-photon absorptiometry.
Quantitative dual-energy radiographic absorptiometry (DRA) and dual-photon absorptiometry (DPA) were compared to determine the best means of assessing bone density. Both methods were used to evaluate the lumbar spine in 107 women (aged 35-84 years [mean, 64 years]) referred for evaluation of osteoporosis risk. High correlation was documented between measurements derived by the two techniques, with a .95 linear regression coefficient for the total spine density measurement. Age-related regression equations were similar in slope but manifested different intercepts. Bone mineral density values derived with DRA were consistently lower than those obtained with DPA (conversion equation: DPA density = [1.067 X DRA density] + 0.163). Besides the inherent imperfections of each system, it was found that inaccurate identification of intervertebral spaces on the low-resolution DPA images introduced errors in patient data. DRA may replace DPA as the dedicated projectional densitometric procedure of choice for technical reasons, but at present a conversion equation must be used to compare DRA data to DPA data.
Borders
J
J
Department of Radiology, University of California San Diego Medical Center 92103-1990.
Kerr
E
E
Sartoris
D J
DJ
Stein
J A
JA
Ramos
E
E
Moscona
A A
AA
Resnick
D
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003720:Densitometry; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000378:metabolism; D008722:Methods; D008875:Middle Aged; D008903:Minerals / Q000378:metabolism; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000378:metabolism; D011877:Radionuclide Imaging
D008903:Minerals