Evaluation of coronary stenosis by using the gemstone spectral CTCA:a phantom study / 天津医药

ABSTRACT

Objective To evaluate the diagnosis accuracy for coronary stenosis from diameter measurements of differ?ent severities of stenosis by using gemstone spectral imaging (GSI). Methods Totally 3 different coronary artery models(in?ternal diameter3.00 mm) that with different severities of stenosis (residual lumen diameter ratio75%, 50%and 25%) were placed in a pulsating cardiac phantom (ALPHA 1-VT PC, Fuyo Corporation, Japan). The coronary phantom was scanned in two modelsgemstone spectral imaging (GSI) and axial scan model(AXIAL). All the spectral imaging data were analyzed by using GSI viewer to reconstruct the VMS images (40-140 keV by 10 keV interval) and AXIAL. CT values (HU) of the re?mained lumen from all different stenosis lumens were measured. The residual rate (%) was calculated by dividing the diame?ters of the remained lumen to normal lumen on the reformatted short axial images. One-way ANOVA was used to compare the measurement difference of residual rates between VMS images. Student t-test was used to compare the measurement dif?ference of residual rate between VMS and AXIAL. Bland-Altman test was used to compare the measured residual rates and the gold standard. Results There were no significant differences in measured residual rate betweeb VMS images (P>0.05). From student t-test, only significant difference was found on 50%stenosis between 70 keV VMS and AXIAL(t=4.617,P<0.042). From the Bland-Altman test, measurement of residual rate was more accurate from 70 keV VMS than that of AXIAL by taking the stenosis rate of real model as gold standard(t=14.560,P<0.001). Conclusion VMS image (70 keV) shows more accurate rate than AXIAL images on both diameter measurement and evaluation of the coronary stenosis.