Applied research on double low scanning technique in gem spectrum ct coronary artery angiography / 实用放射学杂志

ABSTRACT

Objective To investigate the feasibility of double low scanning technique using the gem spectrum CT coronary artery angiography among the patients at low heart rate≤ 65 beats per minute.Methods This prospective study was approved by the institutional re-view board with patient informed consent.Ninty patients (heart rate≤65 beats per minute)were randomly devided into 3 groups.Group A un-derwent spectral CCTA with iodixanol (Visipaque,270mg/mL)and low scanning technique,Group B conventional CCTA with iohexol (Omnipaque,370 mg/mL)and Group C conventional CCTA with iodixanol (Visipaque,270 mg/mL),Routine scan mode was used in Group B and Group C.Prospective ECG gating mode was used in all groups.120kVp polychromatic images with FBP algorithm (Group B and Group C)were reconstructed for conventional CCTA,60 keV monochromatic images with FBP algorithm (Group A) or with a fixed blending level (40%)of ASiR (Group A1 )were reconstructed for spectral CCTA.Compared the image quality of four groups and ED in three groups.Results The difference was ststistically significant between four groups with the CT value,im-age noise,SNR and CNR of coronary (each P<0.001.Group A1 has the highest SNR and CNR.Group C has the lowest image noise.There were no significant difference of coronary score between group A1 and group B(χ2=0.01,P=1.000)).There was significant difference of coronary score between group A and group B (χ2=22.428,P<0.001),group B and group C (χ2=39.005,P<0.001), group A1 and group A (χ2=21.854,P<0.001).Effective radiation dose in the group A(ED2.60±0.26 mSv)was lower than that of group B (ED3.02±0.36 mSv)(t=3.738,P=0.001)and group C (ED3.11±0.23)(t=3.725,P=0.001).Conclusion Double low scan-ning technique using the gem spectrum CT coronary artery angiography with 40% blending level of ASiR is able to provide better im-age quality than using conventional CCTA and to reduce the effective radiation dose and contrast dose.