Dual-photon absorptiometry: comparison of bone mineral and soft tissue mass measurements in vivo with established methods

Dual-photon absorptiometry (DPA) has recently been applied to the assessment of body composition. To evaluate the accuracy of DPA in detecting small changes in the lean soft tissue mass, we performed DPA with the use of the Norland 2600 Dichromatic densitometer on six healthy adult males before and after a 30-ml/kg transfusion of saline and before and after exercise in a warm environment, resulting in a greater than or equal to 1-kg weight loss. Absolute weight [baseline pretransfusion r2 = 0.999, standard error of estimate (SEE) = 590 g; posttransfusion r2 = 0.999, SEE = 300 g; baseline pretranspiration r2 = 0.999, SEE = 230 g; posttranspiration r2 = 0.999, SEE = 240 g] was accurately reflected in DPA total mass. Weight changes due to transfusion were poorly reflected by changes in DPA total mass (r2 = 0.417, SEE = 404 g). However, changes posttranspiration were accurately reflected in the DPA total mass (r2 = 0.886, SEE = 106 g posttranspiration). Similarly, weight changes due to transfusion were poorly measured by changes in DPA soft mass (r2 = 0.478, SEE = 365 g), but changes posttranspiration were highly correlated with DPA soft mass changes (r2 = 0.909, SEE = 92 g). Weight changes were not reflected by changes in the DPA lean soft tissue mass (r2 = 0.006, SEE = 1,737 posttransfusion, r2 = 0.094, SEE = 1,038 g posttranspiration). DPA-derived nonfat mass was highly correlated with skinfold-derived nonfat mass (r2 = 0.96, SEE = 2,400 g). Accuracy of total and soft tissue measurements implied correct mineral mass assessment.(ABSTRACT TRUNCATED AT 250 WORDS)

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AGE IMPACTS THE RELATIONSHIP OF SOFT TISSUE MASS TO BONE MINERAL DENSITY

Medicine & Science in Sports & Exercise ◽

10.1097/00005768-199905001-01081 ◽

1999 ◽

Vol 31 (Supplement) ◽

pp. S228

Author(s):

D. L. Nichols ◽

C. F. Sanborn ◽

C. J. Heiss

Keyword(s):

Bone Mineral Density ◽

Soft Tissue ◽

Bone Mineral ◽

Soft Tissue Mass ◽

Mineral Density ◽

Tissue Mass ◽

Relationship Of ◽

The Relationship

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Dual Photon Absorptiometry for Bone Mineral Measurements Using a Gamma Camera

Acta Radiologica ◽

10.1177/028418519403500110 ◽

1994 ◽

Vol 35 (1) ◽

pp. 45-52

Author(s):

R. Valkema ◽

H. Prpic ◽

J. A. K. Blokland ◽

J. A. J. Camps ◽

S. E. Papapoulos ◽

...

Keyword(s):

Bone Mineral ◽

Gamma Camera ◽

Dual Photon Absorptiometry ◽

Camera System ◽

Photon Absorptiometry ◽

Camera Systems ◽

Bone Mineral Measurements

A gamma camera was equipped with a special collimator and arm assembly for bone mineral measurements with dual photon absorptiometry (DPA). The system was evaluated in vitro and in vivo and compared both with a rectilinear DPA and a dual energy X-ray (DEXA) system. All 3 systems showed a linear response in measurements of 4 vials, containing different amounts of hydroxyapatite. Phantom measurements with the gamma camera system showed a precision of 1.6% to 2.8%. Results obtained in 8 healthy volunteers with rectilinear and gamma camera systems were well correlated (R2 = 0.78). With the photon beam directed from posterior to anterior, the separation of vertebrae was easy with the gamma camera system. We conclude that bone mineral measurements can be made with a gamma camera for assessment of fracture risk and in the decision process whether a patient needs treatment or not. For follow-up, the precision of DPA with a gamma camera is inadequate.

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IN VIVO ESTIMATION OF TOTAL BODY BONE MINERAL BY DUAL PHOTON ABSORPTIOMETRY. PRECISION AND ACCURACY

Journal of Computer Assisted Tomography ◽

10.1097/00004728-198306000-00040 ◽

1983 ◽

Vol 7 (3) ◽

pp. 550 ◽

Cited By ~ 6

Author(s):

Anders Gotfredsen ◽

Jens Borg ◽

Claus Christiansen

Keyword(s):

Bone Mineral ◽

Dual Photon Absorptiometry ◽

Photon Absorptiometry ◽

Precision And Accuracy ◽

Total Body ◽

Total Body Bone Mineral ◽

Body Bone

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Measurement of Bone Mineral Content to Facilitate an Objective Evalution of Limp Function in the Dog

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.1055/s-0038-1633132 ◽

1994 ◽

Vol 07 (03) ◽

pp. 118-123 ◽

Cited By ~ 2

Author(s):

M. M. Petersen ◽

A. Wenck ◽

Henriette Strøm ◽

E. Svalastoga

Keyword(s):

Bone Mineral Content ◽

Functional Status ◽

Bone Mineral ◽

Mineral Content ◽

Objective Measure ◽

Dual Photon Absorptiometry ◽

Photon Absorptiometry ◽

Significant Difference

SummaryThe aim of this study was to evaluate the feasibility of using measurements of bone mineral content (BMC) and bone mineral density (BMD) by dual photon absorptiometry (DPA; Gadolinium-153), as an objective measure of limb functional status in the dog. The in vitro accuracy error expressed as the standard error of the estimate (SEE) for BMC and BMD measurements was 3.2% and 1.1% respectively, and the precision in vivo for measurements of BMC and BMD in the distal diaphysis of the tibia and fibula was 2.1% and 1.9% respectively. A significant difference in bone mineral between right and left leg was not found in normal dogs, and in these dogs the average percentage intra-individual difference, between bone mineral in the legs with the highest bone density and the legs with the lowest density, was 2.2% and 3.7% for BMC and BMD respectively. However the BMC and BMD in eight clinical cases of unilateral lameness were significantly decreased in the affected legs, when compared to the healthy contralateral legs, by 20.4% (P = 0.01) and 18.3% (P = 0.01)respectively. Measurements of BMC and BMD by DP A in weight-bearing extremities in the dog showed that bone mineral is highly sensitive to decreased loading of the extremity. This method might well be used not only as an objective measure of limb activity, but also for measurement of prospective changes in bone mineral, following treatment of musculoskeletal diseases and injuries.The feasibility of using bone mineral measurements by dual photon absorptiometry, as an objective measure of limb functional status in the dog, was evaluated. Precision and accuracy were calculated from in vitro and in vivo studies. In eight cases of unilateral lameness bone mineral was significantly decreased (20%) in the affected legs when compared to the healthy contralateral legs.

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