This cross-sectional study asks whether Hounsfield units (HU) from routine CT can serve as a surrogate for DEXA-measured bone mineral density. Twenty-five patients with paired lumbar CT and DEXA scans were analyzed, along with normative data from 80 trauma patients and a foam compression biomechanical model. The central question: can a number already embedded in every CT scan tell you whether bone is osteoporotic before you place an implant or miss a fragility fracture?
Every lumbar CT already contains a bone density measurement — almost no one was reading it. This paper established that measuring HU in the vertebral body medullary space on any CT (trauma, abdominal, preoperative) is reliable (ICC > 0.96) and correlates meaningfully with DEXA T-scores.
When you see lumbar HU below 118 on a CT obtained for any reason, that patient warrants DEXA referral. Values at or below 80 HU put them squarely in the osteoporotic range by this study's thresholds.
Before placing pedicle screws, measure HU in the planned screw trajectory on the preoperative CT. Low HU predicts a poor bone-screw interface before a single instrument touches the patient. This is why opportunistic HU assessment has become standard practice in spine surgery planning.
One nuance worth knowing: HU samples only cancellous bone, while DEXA integrates cortical bone too. The moderate r² (0.44–0.48) reflects this difference, not measurement error.
This cross-sectional study asks whether Hounsfield units (HU) from routine CT can serve as a surrogate for DEXA-measured bone mineral density. Twenty-five patients with paired lumbar CT and DEXA scans were analyzed, along with normative data from 80 trauma patients and a foam compression biomechanical model. The central question: can a number already embedded in every CT scan tell you whether bone is osteoporotic before you place an implant or miss a fragility fracture?
Every lumbar CT already contains a bone density measurement — almost no one was reading it. This paper established that measuring HU in the vertebral body medullary space on any CT (trauma, abdominal, preoperative) is reliable (ICC > 0.96) and correlates meaningfully with DEXA T-scores.
When you see lumbar HU below 118 on a CT obtained for any reason, that patient warrants DEXA referral. Values at or below 80 HU put them squarely in the osteoporotic range by this study's thresholds.
Before placing pedicle screws, measure HU in the planned screw trajectory on the preoperative CT. Low HU predicts a poor bone-screw interface before a single instrument touches the patient. This is why opportunistic HU assessment has become standard practice in spine surgery planning.
One nuance worth knowing: HU samples only cancellous bone, while DEXA integrates cortical bone too. The moderate r² (0.44–0.48) reflects this difference, not measurement error.