The value of DLIR algorithm in optimizing the image quality of low-kV head and neck CT angiography

SHEN Li; REN Zhanli; PENG Hui; YU Yong; ZHANG Ming; YU Nan; YAN Yangyang

doi:10.12122/j.issn.1674-4500.2025.11.07

Abstract：Objective To investigate the apllication value of deep learning image reconstruction(DLIR)algorithms in optimising the images quality of low-kV head and neck CT angiography(CTA).Methods Sixty patients who underwent head and neck CTA in the Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine Hospital from October 2024 to February 2025 were analyzed.The scanning was performed with 80 kV and smart mA(50-400 mA).The contrast agent dosage was 40 mL,the flow rate was 4 mL/s,and the injection time of contrast agent was 10 s.After scanning,40%adaptive iterative reconstruction algorithm-V(ASIR-V40%),low intensity DLIR(DLIR-L),medium intensity DLIR(DLIR-M)and high intensity DLIR(DLIR-H)were reconstructed respectively.The CT and SD values of the aortic arch,2 cm above the opening of the common carotid arteries bilaterally,segment V1 of the vertebral arteries,proximal basilar artery,segment M1 of the middle cerebral artery,and temporalis muscle were measured,and signal-to-noise ratios(SNR)and contrast-to-noise ratios(CNR)were calculated.The images were subjectively scored by two radiologists using a five-point scale in a double-blind method.The SD value,CT value,CNR value,SNR value and subjective score of the four reconstruction algorithms were compared.Results There was no statistically significant difference in CT values for each vessel between the four reconstruction algorithms(P>0.05).As the reconstruction levels of ASIR-V40%,DLIR-L,DLIR-M and DLIR-H gradually increased,the images showed a decreasing trend in SD,and an increasing trend in CNR and SNR.Among them,DLIR-H has the lowest SD value and the highest CNR and SNR.Moreover,there are statistically significant differences in the SD,SNR,and CNR values between DLIR-L,DLIR-M,DLIR-H and ASIR-V40%(P<0.05).Compared with ASIR-V40%,DLIR-H Reconstruction the SNR and CNR of the aortic arch,2 cm above the common carotid artery opening,V1 segment of the vertebral artery,proximal basilar artery,and M1 segment of the middle cerebral artery in DLIR-H increased by approximately 69%,48.3%,48.3%,51.6%,56.4%and 68%,55.9%,48.2%,51.6%,56.6%respectively,and the SD values decreased by approximately 40.2%,35.8%,30.6%,33.2%,35.3%respectively.The subjective scores of DLIR-H,DLIR-M and DLIR-L were all higher than those of ASIR-V40%,and the differences were statistically significant(P<0.05).Conclusion Compared with ASIR-V at 40%,DLIR reconstruction can further reduce image noise and improve image quality in head and neck CTA.Therefore,the DLIR algorithm can be used to enhance the image quality of low-kV head and neck CTA.