ABSTRACT
Objective To evaluate the clinical value of spectral CT monochromatic imaging in improvement of imaging quality of bronchial arteries.Methods We retrospevtively analyzed the chest CT images in 38 patients who underwent the contrast-enhanced spectral CT.These images included a set of 140 kVp polychromatic images and default 70 keV monochromatic images.Using a standard Gemstone Spectral Imaging (GSI)viewer at an advanced workstation (AW4.6),an optimal energy level (in keV)for obtai-ning the best CNR of the bronchial artery could be automatically obtained.The SNR,CNR and objective imaging quality score for these 3 imaging sets (140 kVp,70 keV and optimal energy level)were obtained and compared with one-way ANOVA .Results The optimal energy levels for obtaining the best CNR were (62.58±2.74)keV.The SNR of the 140 kVp polychromatic images,70 keV monochromatic images,and the optimal keV monochromatic images were 1 6.44±5.85,20.96 ±8.32 and 24.91 ±9.91,the CNR were 13.30±5.45,1 7.25±6.97 and 20.67±8.62,and the subjective imaging quality scores were 1.97 ±0.82,3.24±0.75 and 4.47±0.60,respectively,exhibiting significant differences among groups (F =10.1 7,10.1 7 and 1 1 1.12,P <0.00).The optimal monochromatic group was superior to the 70 keV group and the 140 kVp mixed-energy group.Conclusion Monochromatic images at approximately 62 keV in dual-energy spectral CTA yields the best CNR and highest diagnostic confidence for imaging bronchial ar-teries,which may improve imaging quality for imaging bronchial arteries.
