There was significant difference in the CT attenuation of RCA , LAD and CX among the @ groups ( P < @ ) , the CT attenuation was the highest in group B , the CT value of RCA , LAD and CX were @ @ , @ @ , @ @ HU , respectively.the CT attenuation was the lowest in group C , the CT value of RCA , LAD and CX were @ @ , @ @ , @ @ HU , respectively .