Low-dose expiratory CT can be used with dual-gas quantitative analysis in patients with chronic obstructive pulmonary disease
CHANG He
MA Guangming
YU Nan
TIAN Qian
Abstract：Objective To explore the application value of low-dose expiratory phase scanning scheme in dual-gas phase quantitative CT diagnosis of chronic obstructive pulmonary disease(COPD)and qantitative analysis by reducing the radiation dose of expiratory phase during dual-gas phase scanning.Methods Sixty-seven patients with COPD confirmed by clinical pulmonary function tests at Affiliated Hospital of Shaanxi University of Chinese Medicine from October 2023 to March 2024 were prospectively included.The first expiratory and inspiratory phase scans were performed with a standard radiation dose(NI=14)and the second expiratory phase was scanned with a low radiation dose(NI=28).Both CT examinations used 60%ASIR.The CT value and the SD value of adipose tissue,muscle tissue and aorta were measured,and signal noise ratio were calculated.The thin-slice reconstruction images from the standard-dose group and the low-dose group were imported into the"Digital Lung"data analysis platform for dual-phase matching,and quantitative parameters were measured(lung volume,emphysema volume,Emph%,functional-small airways volume,fSAD%,LAA-910%,LAA-950%).The radiation dose,quantitative CT parameters and image subjective score were compared between low-dose group and standard-dose group.Results The radiation dose of the expiratory low-dose group was lower than that of standard-dose group(P<0.05).There was no significant difference in the two-gas phase registration parameters between the low-dose group and the standard-dose groups(P>0.05).The SD value in the expiratory phase of the low-dose group was greater than that in the standard-dose group(P<0.05).There was no significant difference in the ratings between the two groups(P>0.05).Conclusion The use of a low-dose scanning protocol for expiratory-phase scanning in the quantitative evaluation of COPD patients by dual-phase scanning ensures that the quantitative CT evaluation results are consistent with the standard-dose,meeting the needs of the evaluation while significantly reducing the radiation dose received by the patient.
Keywords：low doseCT quantitative analysischronic obstructive pulmonary diseasedual phase CT
Publication Date：2025-04-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 419-423 )