【摘要】 目的:尝试配制一种应用于直肠/阴道腔内的短T₂效应MRI对比剂,旨在提高阴道和直肠MRI质量。方法:将右旋糖酐铁溶液与超声耦合剂按不同比例混合,配制成含铁浓度分别为0.125、0.375、0.625、1.250、1.875、2.500、3.125和3.750 mg/g共8种浓度的对比剂（实验组）,以纯超声耦合剂和纯右旋糖酐铁溶液作为2个对照组。将3组混和均匀的物质分别注入不同的试管中进行3.0T MRI检查,扫描序列包括FSE T₁WI、FRFSE T₂WI和T₂-mapping,其中T₂-mapping序列重复扫描50次。测量8支试管的T₂值。比较实验组不同铁浓度对比剂的T₂值,筛选出最佳短T₂效应的含铁浓度。结果:纯超声耦合剂和纯右旋糖酐铁溶液的T₂值分别为（773.90±5.04）和（83.00±3.40）ms。实验组中8种含铁浓度的对比剂的T₂值依次为（931.04±19.44）、（867.4±18.89）、（832.98±19.40）、（622.88±7.74）、（88.68±4.15）、（62.80±9.23）、（26.82±4.30）和（18.24±3.68）ms,各组间差异有统计学意义（F=53644.11,P<0.001）。随着对比剂铁含量的增高,在T₂WI上的信号呈下降趋势;当铁含量为3.125 mg/g时,信号强度与无信号背景接近,同时其在T₁WI上的信号强度与纯超声耦合剂相当。结论:铁浓度为3.125 mg/g的右旋糖酐铁溶液与超声耦合剂的混合剂可作为直肠和阴道腔内较合适的短T₂效应对比剂。更多还原

【Abstract】 Objective:The purpose of this study was to explore an appropriate contrast agent with short-T₂ effect for rectal or vaginal MR imaging,thus to improve the quality of vaginal and rectal MR image quality.Methods:Eight contrast agents with different iron contents of 0.125,0.375,0.625,1.250,1.875,2.500,3.125 and 3.750 mg/g were formulated as experimental groups using different proportions of iron dextran solution and ultrasonic coupling agent.Pure ultrasonic coupling agent and pure dextran iron solution were used as the control groups.Three sets of uniformly mixed solutions were placed in test tubes with the same tube holder,and underwent MR scan at a 3.0 T MR scanner with sequences of FSE-T₁WI,FRFSE-T₂WI and T₂-mapping.The T₂-mapping sequence was scanned for 50 times.The T₂-values of the contrast agents with different iron contents were measured and compared statistically.Results:On T₂-mapping,the T₂-values of the pure ultrasonic couplant and the pure iron dextran were（773.90±5.04） and（83.00±3.40）ms,respectively;and the T₂-values of the eight concentrations of contrast agents in the experimental group were（9931.04±19.44）,（867.4±18.89）,（832.98±19.40）,（622.88±7.74）,（88.68±4.15）,（62.8±9.23）,（26.82±4.30） and（18.24±3.68）ms,respectively.There was significantly statistical difference among the eight contrast agents with diffe-rent concentrations（F=53644.11,P<0.001）.The signal intensity of the contrast agents on T₂WI decreased with the increase of the iron content of the contrast agents.When the iron content was 3.125 mg/g,the signal intensity was nearly equal to the background with the naught signal,and at the same time,its signal intensity on T₁WI was nearly equal to the signal intensity of the pure ultrasonic coupling agent.Conclusion:The mixture of iron dextran solution containing 3.125 mg/g of iron and ultrasonic coupling agent can be used as a feasible contrast agent in the MRI examination of rectal and vaginal cavities.更多还原