5 Lumbar Vertebral Bodies with Lowest Ribs on T11 vs. 6 Lumbar Vertebral Bodies

Case Description:

This Hologic lumbar spine DXA shows either 6 lumbar vertebral bodies, vs 5 lumbar vertebral bodies with no ribs on T12 (i.e. lowest ribs on T11). The correct analysis is to count up from the bottom up, using the iliac crest to designate the L4-L5 interspace. Peel et al. (see reference below) found that among a sample of women, 83.5% had 5 lumbar vertebral bodies with the lowest ribs on T12. This means that 16.5% of women have other segmentation combinations.  0.8% of individuals have 6 lumbar vertebral bodies with the lowest ribs on T12. 7.2% of women have 5 lumbar vertebral bodies with the lowest ribs on T11.  Therefore, it is most likely that this represents 5 lumbar vertebral bodies with the lowest ribs on T11.

Credit:

Sarah L Morgan, MD, RD, CCD, The University of Alabama at Birmingham

References:

• Peel, N.F., et al., Impact of anomalous vertebral segmentation on measurements of bone mineral density. J Bone Miner Res, 1993. 8(6): p. 719-23.