快速千伏切换能谱CT与QCT测定羊椎体骨密度的相关性及一致性研究.

Objective To evaluate the agreement of the bone mineral density(BMD) measurements by using a phantomless dual-energy CT compared with conventional quantitative CT(QCT) in sheep vertebral specimen. Methods Twenty-three fresh sheep vertebrae were scanned by QCT and dual-energy CT on the same CT scanner which generated dual-energy images from rapid kilovoltage switches. Trabecular BMD analyses of QCT images were performed using QCTpro software. HAP densities(namely BMD) of the same regions were measured for comparison based on HAP-water material pairs. Pearson correlation, paired t-test, intraclass correlation coefficient(ICC), and Bland-Altman plot were applied for consistency assessment. Results BMD derived from DECT images was(286.7±103.8) mg/cm3 in average, and it was significantly lower than the result of QCT, which was(321.3±123.6) mg/cm3. The two result displayed a strong linear correlation(r=0.989, P<0.001). The ICC between the two measurements was 0.974(P<0.001). Bland-Altman plot was applied after log-transformation of the primary data. Most of the different values were within the range of the mean difference±1.96 SD, indicating a high agreement among measurements. Conclusion BMD measurements derived from the dual-energy CT in vitro displayed a high correlation and agreement with BMD measured by QCT. The phantomless dual-energy CT has the potential to be applied in BMD measurement and follow-up clinically. [ABSTRACT FROM AUTHOR]