Objective To compare the perfusion parameters and image quality of head computed tomography perfusion(CTP)based low radiation dose deep learning reconstruction(DLR)and conventional radiation dose hybrid iterative reconstruction(HIR)techniques.Methods 60 consecutive patients with suspected or known ischemic stroke were retrospectively divided into two groups.A group of 30 patients underwent head CTP scanning with conventional radiation dose and HIR technique to obtain three-dimensional adaptive iterative dose reduction(AIDR 3D)images(AIDR-R).Second group of 30 patients were scanned with low radiation dose and reconstructed using DLR advanced intelligent clear-IQ engine(AiCE)to obtain AiCE-L sequence as well as using HIR to obtain AIDR 3D images(AIDR-L).The cerebral blood flow(CBF),cerebral blood volume(CBV)and mean transit time(MTT)of the three perfusion sequences(AIDR-R,AIDR-L,AiCE-L)were compared.The CT values and standard deviation(SD),signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of the centrum semiovale,carotid siphon,basilar artery and brainstem were determined.Results There was no statistically significant difference in CBF and CBV values between AIDR-R and AiCE-L in the frontal,temporal,occipital,and basal ganglia regions(P>0.05).The MTT values of the AiCE-L sequence in the frontal,temporal,occipital,and basal ganglia regions are higher than those of the AIDR-R sequence(4.03±0.61 vs 4.56±0.84,4.18±0.68 vs 4.76±0.87,4.21±0.62 vs 4.79±0.82,4.05±0.68 vs 4.65±0.91,unit s)(P<0.001).Compared with the images of AIDR-R,the CT values of AiCE-L sequence in the center of semiovale and brainstem were lower than those of AIDR-R[brainstem(47.18±4.11)HU vs(50.62±5.17)HU,center of semiovale(40.93±4.64)HU vs(47.96±4.11)HU](P<0.05).The SD value of AiCE-L was lower than that of AIDR-R[(9.62±4.83)HU vs(9.85±3.46)HU,(9.95±4.96)HU vs(11.08±4.62)HU,(9.85±3.46)HU vs(11.08±4.62)HU](P<0.05),there was no significant difference in CT value,SNR and CNR(P>0.05).Conclusion There was no significant difference in CBF and CBV parameters between the low dose group and the normal dose group.DLR can reduce the SD value of peak arterial phase with image quality similar to conventional dose HIR reconstruction in low-dose head CTP scan.
关键词
深度学习/体层摄影术,X线计算机/灌注/辐射剂量
Key words
Deep learning/Tomography,X-ray computed/Perfusion/Radiation dose