Abstract：Objective To verify the feasibility of evaluating vertebral bone mineral density by using quantitative CT (QCT) to measure the bone mineral density (BMD) of thoracolumbar vertebrae, and the slope of spectral CT attenuation curve with double-layer detector. Methods A total of 128 patients who underwent chest CT examination in the Department of Radiology, Hainan Hospital of PLA General Hospital from July 2019 to December 2019 were collected, and the QCT values of bone cancelation in thoracic 11, thoracic 12 and lumbar 1 vertebrae were measured. The attenuation curve of energy spectrum was quantified by the ratio between the difference of CT values of 40 Kev and 70 Kev level images and the difference of energy level. Person correlation coefficient method was used to analyze the consistency of QCT value and λ value of slope of energy spectrum decay curve of patients, and ROC curve was drawn to analyze the efficacy of slope of energy spectrum decay curve in diagnosing bone mass loss and osteoporosis. Results The average QCT values in thoracic 11,thoracic 12,lumbar 1 vertebra and the whole body were (137.66±34.01) (132.74±31.62) (126.72±31.38) and (132.27±32.35) mg/cm3, respectively, The average λ values were (6.71±1.57) (6.37±1.63) (6.27±1.54) and (6.45±1.59) Hu/kev, respectively. The correlation coefficient r values of thoracic 11, thoracic 12, lumbar 1 and the total QCT value and λ value were 0.931,0.943,0.943 and 0.938, respectively, with excellent consistency and statistical significance(P<0.05). The QCT value of thoracic 11,thoracic 12 and lumbar 1 vertebra in male groups was higher than that of female group, the λ value of thoracic 12 and lumbar 1 vertebra in male group was higher than that of female group, and the difference was statistically significant(P<0.05). The QCT value and λ value of thoracic 11,thoracic 12 and lumbar 1 vertebra in the middle age group were higher than those in the elderly group, and the difference was statistically significant(P<0.05). With QCT value of 120 mg/cm3, λ value of AUC value of 0.978, Jordon index of 0.8678, λ value of cutoff value of 5.90, sensitivity of 92.13%, specificity of 94.66% when diagnosing vertebrae with low bone mass. The patients were grouped with a QCT value of 80 mg/cm3. The ACU value was 0.965, the Jorden index was 0.8662, λ cutoff value was 4.90, sensitivity was 89.40%, and specificity was 97.22% when the vertebrae were diagnosed with osteoporosis. Conclusions The slope of spectral CT attenuation curve with double-layer detector has the potential to evaluate the BMD of thoracolumbar vertebrae, and is feasible in clinical practice.
宗林雄, 黄天俊, 孟庆林, 陈志晔. 双层探测器光谱CT能谱衰减曲线斜率用于评价椎体骨密度值的可行性[J]. 武警医学, 2025, 36(1): 50-54.
ZONG Linxiong, HUANG Tianjun, MENG Qinglin, CHEN Zhiye. Feasibility study on evaluation of vertebral bone mineral density by slope of Dual-layer spectral CT energy spectrum attenuation curve. Med. J. Chin. Peop. Armed Poli. Forc., 2025, 36(1): 50-54.
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