Spinal Level Identifiation

Case Description:

The spinal levels are likely not correctly identified on this GE Healthcare scan. No iliac crest is seen, and what is marked as L1 contains ribs. It is important to have the iliac crest visible to help with spinal level identification. The iliac crest designates the L4-L5 interspace. The first vertebral body above the pelvis is designated L5 in DXA scanning. The reference by Peel below outlines differences in spinal segmentation that are seen. The effect of mislabeling T12 as L1 is to generally to lower BMD over correct labelling (reference below).

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.
• Choplin, R.H., L. Lenchik, and S. Wuertzer, A practical approach to interpretation of Dual-Energy X-ray Absorptiometry (DXA) for assessment of bone density. . Curr Radiol Rep 2014. 2(48).
• Lewiecki, E.M. and N.E. Lane, Common mistakes in the clinical use of bone mineral density testing. Nat Clin Pract Rheumatol, 2008. 4(12): p. 667-74.
• Guan, W., et al., Lumbar Vertebrae Morphological Analysis and an Additional Approach for Vertebrae Identification in Lumbar Spine DXA Images. J Clin Densitom, 2018.
• Sarathi, V., C.V. Rakesh, and S. Tirupati, Effect of T12 Mislabeling as L1 on the Diagnosis of Low BMD at Lumbar Spine. J Clin Densitom, 2020.