BMD T-Score (Lumbar Spine) Test

Bone mineral density (BMD) measures how much mineral, mainly calcium, is packed into your bones. The T-score compares your bone density to that of a healthy young adult of the same sex. It’s one of the most widely used numbers to diagnose osteoporosis (weak bones) and osteopenia (early bone loss). The lumbar spine, which includes the vertebrae in your lower back (L1–L4), is especially useful for detecting early changes because this region contains mostly trabecular bone, a spongy type of bone that’s metabolically active and the first to show signs of bone loss.

• A normal lumbar spine T-score is above -1.0.
• A T-score between -1.0 and -2.5 indicates osteopenia.
• A T-score of -2.5 or lower indicates osteoporosis.

However, lumbar spine readings can sometimes be misleading. With aging, many people develop spinal degeneration, including arthritis, bone spurs, or calcified ligaments, that can falsely elevate BMD readings, making bone density appear healthier than it is. This means someone might have normal-looking spine T-scores but still be at risk for fractures in other areas like the hip or wrist.