Abstract:Objectiv To explore the value of multiparameter imaging in spectral CT for improving the image quality of Corona Virus Disease 2019. Methods A total of 53 groundglass opacity (GGO) lesions and 23 solid lesions on the nonenhanced chest spectral CT images of 15 confirmed COVID19 patients were retrospectively analyzed. Three sets of spectral CT images were selected for analysis,including conventional 120kVplike CT image, monochromatic CT image with the highest contrastnoise ratio (CNR) (OptkeV image) and the waterbased material decomposition (MD) images. CT value (water density) of lesions and standard deviation (SD) of normal lung tissue were measured to calculate signal noise ratio(SNR)and contrast noise ratio(CNR)for lesions, and subjective image quality evaluation was performed.Results The waterbased MD images provided the highest subjective score for GGO than the other CT images (all P<0.05). For solid lesions, the waterbased MD images and OptkeV images had similar subjective scores (all P>0.05) and were both higher than the 120kVplike images (all P<0.05). The differences in SD values,SNR and CNR between GGO lesions and solid lesions on the 120kVplike images, Opt-keV images and the waterbased MD images were statistically significant (all P<0.05). Conclusion The spectral CT multiparameter analysis can effectively reduce image noise through selecting OptkeV CT image and using waterbased MD image to improve lesion CNR. Waterbased MD image has more obvious advantages in improving the image quality of COVID-19 groundglass lesions.