Imaging quality optimization of myocardial perfusion with spectral CT

MA Shuai; SHAO Guangrui; LI Zhaohua; ZHAO Yong; JI Yu

Abstract：Objective To explore the optimum match of monochromatic energy level and adaptive statistical reconstruction (ASiR) for monochromatic reconstruction of myocardial CT perfusion (CTP) images with dual-energy CT.Methods Thirty sub-jects with suspected coronary artery disease ( CAD) were scanned on spectral CT , conventional polychromatic images and 10 sets of monochromatic images (60, 65, 70, 75, 80, 90, 100, 110, 120, and 130 kiloelectron volts ( keV); each with increasing contributions of ASiR , ie, 0%, 20%, 40%, 60%, 80%) was obtained from a single gemstone spectral imaging ( GSI) acquisi-tion.The background noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and beam-hardening artifacts (BHA) of the specific myocardial segment in monochromatic images were assessed by ANOVA test and were compared with conventional pol -ychromatic groups .Results With the increase of monochromatic energy imaging noise , BHA decreased , reaching the noise ’ s nadir at 75keV level.Adding 40%or more ASiR contributed to the reduction of the noise , while for BHA, this seemed ambigu-ous.Compared with conventional polychromatic images , reconstructions with 75 keV showed the highest improvement in SNR (48%, P <0.001, combined with 80%ASiR) and CNR (35%, P <0.001, combined with 60%ASiR).Conclusion Mono-chromatic reconstruction at 70~75 keV combined with 40%ASiR can offer satisfactory reduction of noise and BHA , meanwhile , obtains superior SNR and CNR in this myocardial CTP scan with spectral CT .