Purpose Based on European lumbar spine phantom,to investigate the effect of different noise index(NI)combined with adaptive statistical interactive reconstruction-veo(ASiR-V)weights on the measurement of lumbar spine bone density,and to explore the optimal combination of the two parameters.Materials and Methods Using GE Revolution CT spectral imaging scanning,54 groups of scanning parameters with NI values of 4-20(interval 2)combined with ASiR-V weights of 0-100%(interval 20%)were selected for spectral scanning of European lumbar spine phantom.Regions of interest were placed in the middle of L1,L2 and L3,respectively.hydroxyapatite(HAP)-H2O based substances were selected to measure the HAP content of each vertebral body.The differences between the measured bone density value and the true value under different NI combined with different ASiR-V were compared to evaluate its accuracy.Results There were statistically significant differences in HAP measurements of L1,L2 and L3 vertebra in 54 groups of scanning conditions(all P<0.001).When NI=14,ASiR-V80%;NI=16,ASiR-V100%;NI=18,ASiR-V60%;NI=18,ASiR-V80%;NI=20,ASiR-V60%;NI=20,ASiR-V80%;NI=20,ASiR-V100%,there was no statistically significant difference between HAP measured value and true body model value(P>0.05).Conclusion With NI=18,ASiR-V60%,spectral CT can accurately measure lumbar spine bone density and significantly reduce the radiation dose.In clinical application,bone density can be measured by low dose scanning by increasing the weight of NI and ASiR-V.
PhantomsTomography,X-ray computedAdaptive statistical interactive reconstruction-veoNoise indexBone density