Reducing Both Radiation Dose and Iodine Intake in 80 kVp Head and Neck CT Angiography Using Deep Learning Image Reconstruction Combined with Contrast-Enhancement-boost Technology:A Comparison with 100 kVp Imaging Using Hybrid Iterative Reconstruction
WANG Yun
ZHANG Xinyue
TONG Jiajing
CHEN Yu
XU Min
WANG Jian
ZHANG Zhuhua
JIN Zhengyu
Abstract：Purpose:To assess the clinical efficacy of integrating deep learning reconstruction(DLR)with contrast-enhancement-boost(CE-boost)in 80kVp head and neck CT angiography(CTA)using substantially lowered radiation and contrast medium(CM)doses,compared to the standard 100kVp protocol using hybrid iterative reconstruction(HIR).Methods:Sixty-six patients were prospectively enrolled and randomly assigned to one of two groups:the low-dose group(n=33),receiving 80kVp and 28mL contrast medium(CM)with a noise index(NI)of 15;and the regular-dose group(n=33),receiving 100kVp and 40mL CM with an NI of 10.For the low-dose group,images underwent reconstruction using both hybrid iterative reconstruction(HIR)and deep learning reconstruction(DLR)at mild-,standard-,and strong-strength levels,both before and after combination with contrast enhancement-boost(CE-boost).This generated eight distinct datasets:L-HIR,L-DLRmild,L-DLRstandard,L-DLRstrong,L-HIR-CE,L-DLRmild-CE,L-DLRstandard-CE,and L-DLRstrong-CE.Images for the regular-dose group were reconstructed solely with HIR(R-HIR).Quantitative analysis involved calculating and comparing CT attenuation,image noise,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR)within six key vessels:the aortic arch(AA),internal carotid artery(ICA),external carotid artery(ECA),vertebral arteries(VA),basilar artery(BA),and middle cerebral artery(MCA).Two radiologists independently assessed subjective image quality using a 5-point scale,with statistical significance defined as P<0.05.Results:Compared to the regular-dose group,the low-dose protocol achieved a substantial reduction in contrast media volume(28mL versus 40mL,a 30%decrease)and radiation exposure((0.41±0.08)mSv versus(1.18±0.12)mSv,a 65%reduction).Both L-DLRstandard and L-DLRstrong delivered comparable or superior SNR and CNR across all vascular segments relative to R-HIR.However,subjective image quality scores for L-DLR at all strength levels fell below those for R-HIR(all P<0.05 for both readers).Combining CE-boost with the low-dose protocol significantly enhanced the objective image performance of L-DLRstrong-CE(all P<0.05)and produced subjective image scores comparable to R-HIR(reader 1:P=0.15;reader 2:P=0.06).Conclusion:When compared to the standard 100kVp head and neck CTA,the combination of the DLR and CE-boost techniques at 80kVp can achieve a 30%reduction in contrast dose and a 65%reduction in radiation dose,while maintaining both objective and subjective image quality.
Keywords：computed tomography angiographyradiation dosagedeep learning reconstructionimage quality
Publication Date：2025-11-30
Online Publishing Date：2025-12-19(First online date of this platform, not the publication date of the document)
Pages：10( 1082-1091 )