Vertebral density distribution pattern: CT classification of patients undergoing maintenance hemodialysis

The authors performed densitometry of the vertebral bodies in 152 patients undergoing renal hemodialysis and histologically examined four vertebrae from cadavers. Bone mineral density (BMD) values were found to be potentially misleading because the vertebrae are often heterogeneous, and the BMD value is merely an average value from one region of interest. To overcome this problem, the authors designed a computed tomographic classification that divides vertebral density distribution patterns into the following five types: normal (type 1), osteopenia (type 2), diffuse osteosclerosis (type 3), spotty osteosclerosis (type 4), and central osteosclerosis (type 5). This classification may be useful in the evaluation of bone changes in patients undergoing hemodialysis. The type 5 pattern is thought to be strongly related to secondary hyperparathyroidism and was often seen in younger patients and women. Many patients with aluminum-induced osteopathy had type 2 patterns, with decreased BMD in cortical bone.