ABSTRACT
Objective To explore application of the bolus-triggered technique and optimal match between collimation and pitch of MSCTA in intracranial and cervical arteries.Methods(1)The small-dose tests were performed in 19 healthy volunteers and the theoretical threshold was obtained by the time-density curve.(2)forty healthy volunteers were divided randomly into two groups and the scanning parameters were as follows.Group A:collimation 1.0 mm,pitch 1.750. Group B:collimation 2.5 mm,pitch 0.625. Statistical significance was determined with the X~2 test and t test(?=0.05).Results(1)In 19 volunteers,CT value 4 seconds before the peak was 75 HU,the CT value at the beginning segment of the carotid artery and the C_1 segment of internal carotid artery was in accordance with the standard.(2)Image quality ofⅠ,Ⅱgrades artery structures of group B was superior to that of group A.Image quality ofⅢ,Ⅴ grades artery structures of group A was superior to that of group B.Conclusions(1)MSCTA in intracranial and cervical arteries can display systematically the cerebral and carotid arteries.(2)The bolus-triggered technique can improve the image quality of the target vessels.The image quality of the MSCTA of intracranial and cervical arteries is better with the threshold of 75 HU on the basis of 3.5 ml/s injection rate.(3)On the basis of the same other parameters,the optimal scanning parameters are a collimation of 1.0 mm with a pitch of 1.750.