骨密度定量CT测定的实验和临床研究

应用统一的同时校正技术和测量方法对24个离体椎体和64个活体椎体作了mAs、kVp和机型(Somaton CR、Cytec300、GE9800)对骨密度(BMD)测定影响的研究。结果提示:(1)低mas、低kVp扫描是可行的,既大大降低扫描剂量,又不显著影响BMD值,故具重要的临床应用价值;(2)同机、同kVp扫描能灵敏地反映BMD变化;(3)同kVp或相近kVp不同机型的扫描能增加BMD值的可比性,但不同机型间BMD测量值比较价值有限;(4)使用通用标准校正体模及同时校正技术,制定正规扫描技术和测量方法,能提高测量的准确性和可靠性,避免不必要的重复研究。

Quantitative CT(QCT) for Determination Bone Mineral Density(BMD): An Experiment and Clinical Study

Effect of mAs..kVp and different mode of CT scanners on the determination of vertebral bone mineral density was estimated with simultaneous carlibration technique in vitro and in vivo. Results showed (1)Iow mAs and kVp CT scanning was practicable and of great clinical value because it decreased exposure dose but without severe influence on precision of BMD measurement; (2)CT scanning with the same scanner and kVp was sensitive to the variation of BMD; (3)the comparison of BMD value was limited with different CT scanners, but could be increased with same or near kVp; (4)it was imperative to increase accuracy and reproducibility of QCT to avoid unnecessary repeated study by using general standardized carlibration phantom and simulatanous carlibration technique and setting up a regular scan technique and measurement method.