Bone mineral density in chronic renal insufficiency and end-stage renal disease: how to interpret the scans.

Bone disorders are common in renal disease and stem largely from deregulation of serum levels of calcium and phosphorus. Accurate methods of assessment are required to monitor bone mineral content and density changes in patients with renal disease, but current methods are complicated. Interpretation of dual-energy X-ray absorptiometry (DXA) measurements in children is difficult, because the areal component that is measured does not adequately reflect bone that is constantly growing. In adults with renal disease, the inability of DXA measurements to distinguish between cortical and cancellous bone is problematic. The recent advent of quantitative computerized tomography (QCT), however, does permit resolution of cancellous and cortical bone. In children with renal osteodystrophy, QCT could show reduced cortical bone density and distinguish differences in total bone density between patients with high-turnover bone disease and those with adynamic bone disease. The strengths and limitations of these imaging techniques are discussed extensively.