T-score

Bone density expressed in standard deviations relative to young-adult peak. T ≤ −2.5 = osteoporosis; T between −1 and −2.5 = osteopenia.

Why it matters to buyers: Primary DXA clinical output. Reported on every bone density scan.

Why it matters to engineers: Manufacturer-specific calibration; T-scores across GE Lunar vs Hologic are not perfectly interchangeable.