Evaluation of coronary stenosis by using the gemstone spectral CTCA:a phantom study

MIAO Zhenwei; ZHANG Zhang; LI Dong; YU Tielian

doi:10.11958/20150415

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 diameter:3.00 mm) that with different severities of stenosis (residual lumen diameter ratio:75%, 50%and 25%) were placed in a pulsating cardiac phantom (ALPHA 1-VT PC, Fuyo Corporation, Japan). The coronary phantom was scanned in two models:gemstone 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.