Study on the Feasibility of Application of Aortic CT Angiography with
Ultra-Low Volume Contrast Medium in Optimal Monochromatic
Images of Spectral CT with ASIR Reconstruction
HOU Ping1， LIU Jie1，JIANG Yao-jun1，GAO Jian-bo1， SHI Ming-guo2
1. Department of Radiology, the First
Affiliated Hospital of Zhengzhou
University, Zhengzhou Henan 450052,
China; 2. Xijing Hospital, the Fourth
Military Medical University, Xi’an
Shaanxi 710032, China
Abstract：Objective To evaluate the vascular enhancement and image quality of ultra-low volume
contrast medium at aortic CT angiography by using monochromatic images of spectral CT with ASIR
reconstruction, in compared with conventional 120 kvp scan with 70 mL contrast medium. Methods
Altogether 62 patients who underwent aorta CTA examination on a spectral CT scanner were evenly
and randomLy divided into 2 groups: Experiment Group and Control Group. Experiment Group was
scanned by using GSI mode with contrast agent volume of 0.4 mL/kg and injection rate calculated as
volume / (delay time + exposure time). After the examination, images using 55 keV (with 50%ASIR)
and 70 keV (with filtered back projection, FBP) were reconstructed. Those two sets of images were
regarded as Group A and B. Control Group was scanned by using 120 kVp with contrast agent volume
of 70 mL and 5 mL/s injection rate. The obtained images using filtered back projection (FBP) were
regarded as Group C. CT values and CNR of aorta and its branches were obtained and compared. Results
were statistically analyzed by single-factor analysis of variance and Bonferroni correction among
three groups. The subjective rating score among the three groups was compared by using Kruskal-WallisH test. Results CNR values obtained in Group A, B and C were (18.1±5.8) vs (12.1±4.0)
vs (13.2±1.8) in ascending aorta; (18.3±5.8) vs (12.1±3.8) vs (12.3±1.8) in descending aorta;
(16.8±4.4) vs (11.5±3.7) vs (12.4±2.1) in celiac trunk; (17.2±4.7) vs (11.6±3.2) vs (12.5±1.9)
in renal arteries, with significant differences among the three groups (P values<0.05). CT values for
aorta and its branches were [(358±69), (213±91) and (374±34) HU in ascending aorta; (361±64),
(216±37) and (353±30) HU in descending aorta; (336±55), (205±34) and (354±36) HU in celiac
trunk; (333±54), (201±34) and (356±54) HU in renal arteries for Group A, B and C respectively, with
significant differences among the three groups (P=0.00) and between Group A and B, Group B and C
(P=0.00). There was no significant difference between Group A and C (P>0.05). The amount of contrast
agent for each patient in Experiment Group was (28.8±4.4) mL, while that in Control Group was 70 mL.
There were significant differences of the contrast medium volume between the two groups (F=537.09,
P=0.00). And the contrast injection flow rate for each patient in Control Group and Experiment Group
was 5.0 mL/s and (2.4±0.3) mL/s, respectively, with significant differences between the groups
(P=0.000). Conclusion Monochromatic images of 55 keV with 50% ASIR in spectral aortic CTA using
ultra-low volume contrast medium was feasible. Compared with conventional 120 kVp scan, it could
significantly reduce the amount of contrast agent and injection rate by 60% with improved image quality.
侯平1，刘杰1，蒋耀军1，高剑波1，石明国2. 超低剂量对比剂主动脉CTA检查联合单能量成像和ASIR技术的可行性[J]. 中国医疗设备, 2016, 31(7): 22-25.
HOU Ping1， LIU Jie1，JIANG Yao-jun1，GAO Jian-bo1， SHI Ming-guo2. Study on the Feasibility of Application of Aortic CT Angiography with
Ultra-Low Volume Contrast Medium in Optimal Monochromatic
Images of Spectral CT with ASIR Reconstruction. China Medical Devices, 2016, 31(7): 22-25.
