Electrocardiographically triggered CT angiography of the whole aorta and coronary arteries with high-pitch dual-source CT / 中华放射学杂志

ABSTRACT

Objective To investigate the feasibility of comprehensive assessment of the whole aorta and coronary arteries (CA) simultaneously with high-pitch 128-slice dual-source CT ECG-gated FLASH protocol.Methods A total of 48 consecutive patients with suspected aortic diseases underwent CTA examination of the whole aorta and CA using a ECG-gated FLASH CT protocol (pitch =3.2) without heart rate (HR) control.Aorta,aortic valves and CA were shown with different post-processing modalities.The image quality of the aorta,aortic valves and CA was evaluated and compared according to HR (low HR group ≤ 65 bpm,high HR group ＞ 65 bpm).The scan time,effective dose and contrast medium volume were recorded.Inter-observer differences were calculated by Kappa test.Differences between groups were analyzed by Mann-Whitney test with count data and variance test with measurement data.Results All examinations were completed successfully.The image quality was acceptable in the aorta,aortic valve (100％,48/48) and CA (94.0％,551/586).Percentage of diagnostic quality images was slightly higher in low HR group (94.7％,232/245,93.5％,319/341,Z =-2.504,P ＜ 0.05).Inter-reader reproducibility was 95.8％ (46/48) in the aorta and aortic valve,96.6％ (566/586) in CA,yielded good agreement (Kappa =0.81 and 0.89).The mean attenuation of aorta and CA were higher than 300 HU,especially in low HR group (357.0-446.0) HU.Except proximal segment of right CA,the CNR of whole aorta and coronary arteries were significantly higher in the low HR group (24.5-29.0) than that in the high HR group (20.0-23.1,P ＜0.05).SNR of the whole aorta was higher in the low HR group (13.7-17.9) than the high HR group (11.5-13.9,P ＜ 0.05).The mean scan time was (1.56 ± 0.08) s,effective dose was (4.12 ± 1.23) mSv (2.77-6.77 mSv),and contrast medium volume was (72.8 ± 2.1) ml.Conclusions CT angiography of whole aorta and coronary arteries could be performed simultaueously within 2 seconds with CT ECG-gated FLASH protocol.The images were of diagnostic quality for aortic and CA disease with low dose of radiation and contrast media.However,high HR could decrease the image quality of CA.