Improvement of chest low-dose CT image quality with photon counting detector CT

Objective To compare the image quality of photon-counting detector CT (PCD-CT) images with that of conventional energy-integrating detector CT (EID-CT) images in chest low-dose CT (LDCT) imaging, and to investigate whether PCD-CT can achieve better diagnostic imaging. Methods A total of 76 patients who underwent PCD-CT chest LDCT at the Department of Radiology, Jiangsu Province Official Hospital from February to March 2024 were continuously enrolled (PCD-CT group). Propensity score matching was applied to match 76 eligible EID-CT patients (EID-CT group) who underwent EID-CT chest LDCT at the Department of Radiology, Jiangsu Province Official Hospital from September to December 2023 according to age, gender, and volume CT dose index (CTDIvol). Subjective grading was performed to evaluate image respiratory artifacts and sharpness of interlobular septa. Objective measurements included image noise and signal-to-noise ratio (SNR). Results There was no significant difference in the grading score of respiratory artifacts between the PCD-CT group and the EID-CT group (P=0.127). The grading score of sharpness of interlobular septa in the PCD-CT group was significantly better than that in the EID-CT group (P<0.01). The image noise of lung tissue in the PCD-CT group was significantly lower than that in the EID-CT group [ (61.6±7.7) HU vs (76.7±8.2) HU, t=11.844, P<0.01], and the SNR in the PCD-CT group was significantly higher than that in the EID-CT group (15.1±2.0 vs 11.1±1.5, t=13.481, P<0.01). No significant difference showed in mediastinal tissue noise and SNR between the two groups (P>0.05). Conclusion The image quality of PCD-CT is superior to EID-CT. In chest LDCT imaging, PCD-CT shows great potential in improving image quality.