Results for some four-and eight-electrode instruments tested found poor limits of agreement and in some cases systematic bias in estimation of visceral fat percentage, but good accuracy in the prediction of resting energy expenditure ( REE ) when compared with more accurate whole-body magnetic resonance imaging ( MRI ) and dual-energy X-ray absorptiometry ( DXA ).
22.
Despite these shortcomings, lean tissue mass data collected by means of dual-energy x-ray absorptiometry ( DEXA ) before and after flight compares favorably with data from NASAMir, and the total body and leg losses are in fact less than seen during NASA-Mir or during three separate bed rest studies of similar durations in the range of 20-170 d ( Figure 6-11 ).
23.
The other four recommended tests are single-energy X-ray absorptiometry and peripheral dual-energy X-ray absorptiometry to measure the bones of the forearm, finger and sometimes the heel; radiographic absorptiometry to measure bones in the hand; quantitative computed tomography commonly used to measure spinal bone; and, the least precise, ultrasound densitometry to assess bones in the heel, calf, knee and other peripheral sites.
24.
The other four recommended tests are single-energy X-ray absorptiometry and peripheral dual-energy X-ray absorptiometry to measure the bones of the forearm, finger and sometimes the heel; radiographic absorptiometry to measure bones in the hand; quantitative computed tomography commonly used to measure spinal bone; and, the least precise, ultrasound densitometry to assess bones in the heel, calf, knee and other peripheral sites.
25.
The other four recommended tests are single-energy X-ray absorptiometry and peripheral dual-energy X-ray absorptiometry to measure the bones of the forearm, finger and sometimes the heel; radiographic absorptiometry to measure bones in the hand; quantitative computed tomography commonly used to measure spinal bone; and, the least precise, ultrasound densitometry to assess bones in the heel, calf, knee and other peripheral sites.
