Objective:To explore the feasibility of using vertebral CT values under routine kVp scan of the chest and gemstone spectral imaging(GSI)scan of the abdomen for opportunistic screen-ing of osteoporosis based on quantitative CT(QCT).Methods:Prospective collection of 431 patients who underwent thoracic and abdominal unenhanced scans was made with conventional 120kVp for chest CT scans and GSI mode for abdominal scans.The T11～L1 vertebrae overlapped by the thoracic and abdominal scans were analyzed.The bone mineral density(BMD)of the T11～L1 vertebrae at a conventional 120kVp in the chest was measured using a QCT bone densitometry workstation,while the CT values of the T11～L1 vertebrae at 120kVp in the chest and 70keV single energy in the abdom-inal GSI scan were measured separately.The intra-group correlation coefficient was used to assess the consistency of data measurements,and the Spearman correlation test was used to analyze the correla-tion between vertebral BMD values and CT values.Differences in CT values between different verte-brae were tested using the Friedman rank sum test.By referring to the QCT diagnostic criteria,the vertebrae were divided into osteoporosis,osteopenia and normal bone mass groups,and the Kruskal-Wallis was used to compare the differences in CT values between and within the three groups.Within-group 120kVp-CT values and GSI-CT values were tested using the Wilcoxon rank sum test.The mean BMD values of the T11 to L1 vertebrae were used to determine bone status,and the diagnostic efficacy of the vertebral CT values in assessing bone status was analysed using receiver operating characteristic(ROC)curves.Results:Vertebral BMD was positively correlated with both 120kVp-CT values and GSI-CT values(r=0.976,0.963,P＜0.001).Vertebral CT values from T11 to L1 at 120kVp and GSI were,in order,T11[144.00(72.00),158.00(79.00)],T12[137.00(67.00)150.00(76.00)],and L1[128.00(67.00),137.00(74.00)],with statistically significant differences across and within vertebrae(P＜0.001).The CT values of vertebrae in the normal,osteopenia and osteoporotic groups were[181.50(43.67),199.65(48.57)],[132.20(18.50),144.00(23.00)]and[87.75(22.20),93.30(27.20)]at 120kVp and GSI,respectively,with statistically significant differences in vertebral CT val-ues between the different bone status groups(P＜0.05),and the vertebral GSI-CT values were higher than the vertebral 120kVp-CT values within each group(P＜0.05).The AUC for the diagnosis of os-teopenia was 0.976 and 0.967 for the 120kVp-CT and GSI-CT values respectively,with no statistically significant difference(P=0.0937);the AUC for the diagnosis of osteoporosis was 1.000,with no sta-tistically significant difference(P=1.000).Conclusion:Both routine chest 120kVp and abdominal GSI scan CT values can be used for opportunistic screening of osteoporosis with good diagnostic efficacy.
关键词
骨质疏松/骨密度/定量CT/能谱CT/CT值
Key words
Osteoporosis/Bone mineral density/Quantitative CT/Dual-energy spectral CT/CT values
维普
万方数据