3.0T磁共振下肢动脉3D CE-MRA对比剂用量

Dose of contrast agent in 3D CE-MRA of lower extremity arteries at 3.0T MR system

目的探讨使用3.0TMR仪并行采集快速扫描技术进行腹部至下肢动脉三维对比增强磁共振血管成像(3DCE-MRA)中减少对比剂用量的可行性。方法 30例怀疑下肢动脉狭窄的患者按就诊顺序平均分为A、B两组,使用3.0T磁共振扫描仪行腹部至下肢动脉3DCE-MRA,钆浓度为0.5mmol/ml,A、B两组的使用剂量分别为40ml和20ml。比较两组患者三站图像最大密度投影(MIP)图像质量及原始增强图像末端腹主部动脉、股动脉及腘动脉的信号强度(SI)、信噪比(SNR)和对比噪声比(CNR)。结果 A、B两组所有三站动脉的MIP图像质量均符合诊断要求,差异无统计学意义(P>0.05),B组小腿静脉污染比A组略轻,但差异无统计学意义;A、B两组末端腹主部动脉的SI、SNR及CNR差异无统计学意义。A组股动脉及腘动脉的SI、SNR及CNR均略高于B组,差异有统计学意义(P<0.05)。结论采用3.0TMR仪行腹部至下肢动脉3DCE-MRA,使用20ml钆对比剂获得的图像质量可满足临床诊断。

Objective To explore the feasibility of reducing dose of contrast agent in 3D CE-MRA of lower extremity arteries at 3.0T MR system with parallel acquisition technique.Methods All 30 consecutive patients suspicious of lower extremity artery stenosis underwent 3D CE-MRA at 3.0T MR system with parallel acquisition technique.The patients were divided into group A（n=15）and group B（n=15）.The concentration of gadolinium was 0.5 mmol/ml,and the doses were 40 ml and 20 ml,respectively.Image qualities of maximum intensity projection（MIP）of three stations were assessed.The signal intensity（SI）,signal-to-noise ratio（SNR）and contrast-to-noise ratio（CNR）of the source images of both groups were compared.Results All images of two groups were consistent with diagnostic requirements.No statistically significant difference in MIP image quality was found between two groups.There was less contamination in group B than in group A,but it was not significant.SI,SNR and CNR of distal abdominal artery were not significantly different.SI,SNR and CNR of femoral artery and popliteal artery in group A were higher than those in group B（P0.05）.Conclusion CE-MRA of arteries from abdomen to lower extremity at 3.0T MR system using 20 ml gadolinium contrast can acquire good quality images for clinical diagnosis.