Effects of Spinal Hardware on Spine DXA Analysis
This is a baseline and follow-up scan of an individual with hardware at L3-L4. In this follow-up scan, the rods are not mapped, because autolow was forced during the comparison.
The spine hardware is included within the global region of interest scanned in the spine in both scans.
In this reanalysis of the scan, L3 and L4 are completely removed from the spine global region of interest scanned. Notice the difference in the interval change between 2012 and 2014.
Case Description:
The interval change of L1-L2 was affected by removing L3 and L4 with hardware from the global spine ROI. With the hardware in the ROI it indicates that there is an 88.2% loss since the previous scan. With the hardware removed from the ROI, there is stability in bone density from the previous scan. The rods did not map because AutoLow was forced with the compare scan. The normal analysis, which assumes nothing about the shape of the object, would have found the rods and they would have mapped.
Generally, if there is concern that an artifact may give trouble, it is best to exclude it from the global region of interest scanned.
Credit:
Sarah L Morgan, MD, RD, CCD, The University of Alabama at Birmingham