Lanthanum
This Hologic spine scan shows an internal artifact from lanthanum.
The undo view shows that the lanthanum would be omitted from the soft tissue baseline, though it is impossible to tell how much is over other vertebral bodies.
Case Description:
The left panel shows a Hologic DXA scan with soft tissue opacities and opacities over bone. The right panel shows the undo view. The patient had chronic renal insufficiency and was taking Fosrenal(R) 500 mg TID which is lanthanum. The “undo” view shows that the opacities in the soft tissue are removed from the soft tissue baseline. The lanthanum appears to overly a small portion of L4 and L5. However, it can not be ruled out that there is lanthanum that overlies other spinal levels, therefore the spine will not be useful for diagnosis or follow-up if the patient continues to take the lanthanum. The spine could be scanned if the patient could stop the lanthanum and the lanthanum could be cleared from the bowel. A wrist scan should be added on to the DXA protocol in this patient.
Credit:
Sarah L Morgan, MD, RD, CCD, The University of Alabama at Birmingham
References:
• Furstenberg, A., J. Buscombe, and A. Davenport, Overestimation of lumbar spine calcium with dual energy X-ray absorptiometry scanning due to the prescription of lanthanum carbonate in patients with chronic kidney disease. Am J Nephrol, 2010. 32(5): p. 425-31.
• Walsh, J.P. and A.A. Lteif, Lanthanum carbonate interference with lumbar spine DXA. J Clin Densitom, 2011. 14(4): p. 499-501.