关键词: 颈部增强血管成像, 注射流率, 静脉污染, 图像质量

Abstract: Objective The effects of different contrast agent injection rate on the quality of 3D enhanced MRA images were analyzed, and the optimal contrast agent injection rate on high-quality cervical enhanced MRA images was discussed. Methods Patients with suspected cervical vascular lesions who underwent enhanced cervical MRA were randomly divided into 3 groups according to the injection rate. There were 22 cases in group A（1 mL/s）, 25 cases in group B（2 mL/s）, and 20 cases in group C（3 mL/s）. The quality of arterial images and the degree of venous contamination from raw data were graded by two attending physicians, and the mean scores of the whole artery and venous contamination were calculated. The brachiocephalic trunk, left common carotid artery, left subclavian artery, 1 cm below the bifurcation of bilateral common carotid artery and bilateral same-level vertebral artery, bilateral internal carotid cavernous sinus segment （C4） and basilar artery signal intensity （SI） were measured by another attending physician. Results The average arterial signal of groups A, B and C were 584, 720 and 690 respectively. The mean value of arterial contrast noise ratio （CNR） are 222.50, 272.94 and 280.22 respectively. The above three groups are statistically significant （SI H=8.29, P=0.016, CNR H=7.56, P=0.023, P<0.05）. There was statistical difference in arterial, venous and overall scores （P<0.05）. There was statistical difference not only between groups A and B, but also group A and C in arterial scoring （P<0.017）, but there was no statistical difference between groups B and C （P>0.017）. There was statistical difference between groups A and C in venous contamination score. There was no statistical difference between Group A and Group B as well as that Group B and Group C （P>0.017）, there was no statistical difference between Group A and Group B and Group C （P<0.017）, and there was no statistical difference between Group B and Group C （P>0.017）. Conclusion With the increase of injection rate, the signal intensity of carotid artery increased, the image signal-to-noise ratio increased, but the venous contamination did not increase. Therefore, injection rate of 3 mL/s was recommended for cervical enhanced MRA.

Key words: cervical enhanced MRA, injection rate, venous contamination, image quality