Bone densitometry: how to interpret the results?

Dear Ask The Doctor: I've had a DEXA test of the lumbar spine demonstrated of 0.957 grams per cent. squared z-score 0.957and I need to know what my scores mean , also T-S of -0.7 . I am 44 yrs old , white female , in mentapause

Dear Ginger:

Dual-energy X-ray absorptiometry (DXA) is currently the referred technique for assessing bone mineral density. Bone Mineral Density results are reported as T-scores and Z-scores. T-scores are the number of standard deviations below the mean BMD for young adults. A T-score of 0 means that the patient has a BMD value equal to the mean for young adults. A T-score of -2.5 means that the patient has a BMD value that is 2.5 standard deviations below the mean. A Z-score is the number of standard deviations below or above the mean BMD value for people of the same age.

World Health Organization Criteria for Osteoporosis:

Normal: T -score > -1.0 (below the young adult reference range)

Low Bone Mass (Osteopenia): T-score -1.0 to -2.5

Osteoporosis T-Score < -2.5