
doi: 10.1007/bf00296209
pmid: 1393769
Repeat spine and femur measurements (5 per case) were done on 19 subjects with the DPX-L densitometer operating at 3 mA giving a radiation flux fourfold higher than the earlier DPX model. The precision for spine bone mineral density (BMD) was about 0.55% (L2-L4) and 0.48% (L1-L4) for 2-minute scans (2.4 mrem). The precision was only slightly lower (0.4-0.5%) for 4-minute scans (5 mrem) in a subset of 11 subjects. There was a slight precision advantage for the larger L1-L4 area compared with L2-L4 for 2-minute scans, but no advantage for 4-minute scans. The precision for femoral neck BMD was 1.00 and 0.85% for 2- and 4-minute scans, respectively, with proper positioning. The corresponding values for the Ward's triangle region of the femur were 2.6 and 1.5%. The precision of spine scans was influenced chiefly by variable region location. The precision of femur scans was affected by both patient positioning and location of the region. The 4-minute scans minimized the number of operator changes necessary for analysis. Precision errors can be reduced by up to 50% with utilization of the higher flux, but this does not obviate the need for care in patient positioning and scan analysis.
Absorptiometry, Photon, Time Factors, Bone Density, Humans, Femur, Models, Biological, Spine, Densitometry
Absorptiometry, Photon, Time Factors, Bone Density, Humans, Femur, Models, Biological, Spine, Densitometry
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