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Updated: Jun 2, 2026

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Published on: April 29, 2014
Long-term in-vitro precision of direct digital X-ray radiogrammetry
Alvilde Dhainaut1, Mari Hoff, Johan Kälvesten
1INM, Rheumatology, Norwegian University of Science and Technology, MTS, 7489 Trondheim, Norway. alvilde.dhainaut@ntnu.no
Objective:
Digital X-ray radiogrammetry (DXR) calculates peripheral bone mineral density (BMD) from hand radiographs. The short-term precision for direct DXR has been reported to be highly satisfactory. However, long-term precision for this method has not been examined. Thus, the aim of this study was to examine the long-term in-vitro precision for the new direct digital version of DXR.
Materials And Methods:
The in-vitro precision for direct DXR was tested with cadaver phantoms on four different X-ray systems at baseline, 3 months, 6 months, and in one machine also at 12 months. At each time point, 31 measurements were performed.
Results:
The in-vitro longitudinal precision for the four radiographic systems ranged from 0.22 to 0.43% expressed as coefficient of variation (CV%). The smallest detectable difference (SDD) ranged from 0.0034 to 0.0054 g/cm(2).
Conclusions:
The in vitro long-term precision for direct DXR was comparable to the previous reported short-term in-vitro precision for all tested X-ray systems. These data show that DXR is a stable method for detecting small changes in bone density during 6-12 months of follow-up.
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