Comparison on image quality of 5.0T and 3.0T time of flight MR angiography for displaying anterior choroidal arteries
Objective To compare image quality of 5.0T and 3.0T time of flight MR angiography(TOF-MRA)and displaying choroidal anterior arteries(AChA).Methods Data of 80 patients who underwent head 5.0T(5.0T group,n=40)and/or 3.0T TOF-MRA(3.0T group,n=42)were retrospectively analyzed,among them 2 patients underwent both 5.0T and 3.0T TOF-MRA.The subjective scoring and objective evaluation of image quality were performed,and the results were compared between groups.AChA was divided into proximal,intermediate and distal segments(A1,A2,A3 segment),the quantity of left and right AChA shown on 5.0T and 3.0T TOF-MRA were recorded,and the length and diameter of left and right AChA dispalyed on MRA were comparatively observed.Results The subjective scores of image quality of 5.0T group were higher than that of 3.0T group(5.0[4.0,5.0]vs.5.0[3.0,5.0],Z=6.417,P=0.029).The signal-to-noise ratio(91.01±5.04)and contrast-to-noise ratio(72.47±5.14)of 5.0T group were both larger than those of 3.0T group([62.11±4.16],[48.92±4.62],t=28.339,19.681,both P<0.001).There were 80 segments of AChA-A1,80 of AChA-A2 and 60 segments of AChA-A3 displayed on 5.0T TOF-MRA,while 60 segments of AChA-A1,36 of AChA-A2 and 12 segments of AChA-A3 displayed on 3.0T TOF-MRA,respectively.In 5.0T group,the length of the left and right AChA was(24.01±7.41)mm and(22.72±9.36)mm,with diameter of(1.16±0.12)mm and(1.19±0.14)mm,respectively,whereas in 3.0T group,the relative values were(18.35±8.67)mm,(16.80±6.94)mm,(0.99±0.25)mm and(0.95±0.29)mm,respectively,all in 5.0T group were greater than in 3.0T group(t=3.242,3.183,4.595,3.846,all P<0.001).Conclusion Compared with 3.0T TOF-MRA,5.0T TOF-MRA of AChA might provide better image quality and clearer vessel depiction,being helpful to clinical diagnosis and treatment of ACHA-related cerebral vascular diseases.