Kim Youngjune, Kim Hae Young, Lee Sungsoo, Hong Sehyun, Lee Joon Woo
Department of Radiology, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
Department of Radiology, Asan Medical Center, Seoul, Republic of Korea.
Eur Radiol. 2025 Jun;35(6):3519-3527. doi: 10.1007/s00330-024-11263-9. Epub 2024 Dec 10.
To examine how vertebral attenuation changes with aging, and to establish age-adjusted CT attenuation value cutoffs for diagnosing osteoporosis.
This multi-center retrospective study included 11,246 patients (mean age ± standard deviation, 50 ± 13 years; 7139 men) who underwent CT and dual-energy X-ray absorptiometry (DXA) in six health-screening centers between 2022 and 2023. Using deep-learning-based software, attenuation values of L1 vertebral bodies were measured. Segmented linear regression in women and simple linear regression in men were used to assess how attenuation values change with aging. A multivariable linear regression analysis was performed to determine whether age is associated with CT attenuation values independently of the DXA T-score. Age-adjusted cutoffs targeting either 90% sensitivity or 90% specificity were derived using quantile regression. Performance of both age-adjusted and age-unadjusted cutoffs was measured, where the target sensitivity or specificity was considered achieved if a 95% confidence interval encompassed 90%.
While attenuation values declined consistently with age in men, they declined abruptly in women aged > 42 years. Such decline occurred independently of the DXA T-score (p < 0.001). Age adjustment seemed critical for age ≥ 65 years, where the age-adjusted cutoffs achieved the target (sensitivity of 91.5% (86.3-95.2%) when targeting 90% sensitivity and specificity of 90.0% (88.3-91.6%) when targeting 90% specificity), but age-unadjusted cutoffs did not (95.5% (91.2-98.0%) and 73.8% (71.4-76.1%), respectively).
Age-adjusted cutoffs provided a more reliable diagnosis of osteoporosis than age-unadjusted cutoffs since vertebral attenuation values decrease with age, regardless of DXA T-scores.
Question How does vertebral CT attenuation change with age? Findings Independent of dual-energy X-ray absorptiometry T-score, vertebral attenuation values on CT declined at a constant rate in men and abruptly in women over 42 years of age. Clinical relevance Age adjustments are needed in opportunistic osteoporosis screening, especially among the elderly.
研究椎体衰减如何随年龄变化，并建立用于诊断骨质疏松症的年龄校正CT衰减值临界值。
这项多中心回顾性研究纳入了2022年至2023年期间在六个健康筛查中心接受CT和双能X线吸收法（DXA）检查的11246例患者（平均年龄±标准差，50±13岁；7139例男性）。使用基于深度学习的软件测量L1椎体的衰减值。采用女性分段线性回归和男性简单线性回归评估衰减值如何随年龄变化。进行多变量线性回归分析以确定年龄是否独立于DXA T值与CT衰减值相关。使用分位数回归得出针对90%敏感性或90%特异性的年龄校正临界值。测量年龄校正和未校正临界值的性能，如果95%置信区间包含90%，则认为达到目标敏感性或特异性。
男性的衰减值随年龄持续下降，而42岁以上女性的衰减值则急剧下降。这种下降独立于DXA T值（p<0.001）。年龄校正对于≥65岁的人群似乎至关重要，在此年龄组中，年龄校正临界值达到了目标（针对90%敏感性时敏感性为91.5%（86.3-95.2%），针对90%特异性时特异性为90.0%（88.3-91.6%）），但未校正年龄的临界值未达到目标（分别为95.5%（91.2-98.0%）和73.8%（71.4-76.1%））。
由于椎体衰减值随年龄下降，与DXA T值无关，因此年龄校正临界值比未校正年龄的临界值能提供更可靠的骨质疏松症诊断。
问题椎体CT衰减如何随年龄变化？发现独立于双能X线吸收法T值，男性CT上的椎体衰减值以恒定速率下降，42岁以上女性则急剧下降。临床意义在机会性骨质疏松症筛查中需要进行年龄校正，尤其是在老年人中。
