ObjectiveTo explore the application value of 320-detector CT isocenter scan combined with AIDR-3D reconstruction in reducing radiation dose of coronary CT angiography(CCTA).

MethodsOne hundred and eight patients suspected by coronary heart disease were randomly divided into the A, B and C groups(36 cases each group).The coronary CTA scan with a tube voltage of 120 kV in all patients were implemented.The A group were scanned under traditional position, and the tube current was intelligent milliampere.The B and C groups were scanned under isocenter positions(the heart was set at the center of CT rank hole), and the tube currents were 90% and 60% of the intelligent milliampere, respectively.The Af and Aa groups in A group were obtained using the filtering back projection method and AIDR-3D reconstruction, respectively.The B and C groups were reconstructed using AIDR-3D.The signal-to-noise ratio(SNR), contrast-to-noise ratio(CNR), subjective image quality and radiation dose among Af, Aa, B and C groups were compared.

ResultsThe radiation doses in A, B and C groups gradually decreased in turn(P < 0.01).The results of the subjective image quality scores in four groups showed that the score in Af group was lower than that in other three groups, and the differences of which among other three groups were not statistically significant(P>0.05).The results of the objective image quality scores in four groups showed that the noise in Af group was the highest(P < 0.01), followed by C group(P < 0.01), and which in Aa and B groups were the lowest(P < 0.01).The SNR and CNR in Aa and B groups were the highest(P < 0.01), followed by C group(P < 0.01), and whose in Af group were the lowest(P < 0.01).

ConclusionsThe isocenter CT scan combined with AIDR3D can reduce the radiation dose of CCTA without reducing the quality of coronary imaging.