【摘要】 目的探讨兔肝 VX₂瘤 MR 灌注成像（PWI）的最佳对比剂剂量,并评价 MR 灌注成像对兔肝 VX₂瘤的研究价值。方法采用随机区组设计将20只新西兰 VX₂瘤兔分为5组,每组4只,分别给予5种不同浓度（0.05、0.10、0.20、0.30、0.50 mmol/kg）的钆双胺注射液（Gd-DTPA-BMA）,以相同的流率（2 ml/s）,进行T₂^*W 梯度回波-平面回波成像（T₂^*W-GE-EPI）,对得到的兔肝 VX₂瘤及正常肝实质血流灌注效果进行定量和定性分析。结果以剂量0.2 mmol/kg 时 VX₂瘤灌注具有峰值时刻（TOP,12.50 s）早、达峰时间（TTP,7.50 s）短、最大信号下降百分率(SRR_max,54.33%)满意和平均通过时间（MTT,35.00 s）适中的优点,其 TOP、TIP 和 MTT 与正常肝实质比较差异有统计学意义（P<0.05）。5种浓度随着对比剂剂量的增加,VX₂瘤灌注的 TOP、TTP 逐渐缩短,SRR_max逐渐增大,MTT 明显延长。结论 0.2 mmol/kg 为最优化的兔肝 VX₂瘤 PWI 剂量。更多还原

【Abstract】 Objective To optimize the contrast medium concentration for MR perfusion weighted imaging（PWI）of hepatic VX₂ carcinoma in rabbits,and to evaluate the diagnostic value of MR PWI.Methods Twenty New Zealand White rabbits with VX₂ carcinoma were divided into 5 groups in a randomized block design,and T₂^*-weighted imaging with gradient-echo EPI was performed in rabbits after intravenous administration of contrast agent（Gadodiamide Injection,Gd-DTPA-BMA）with five different concentrations（0.05,0.10,0.20,0.30,0.50 mmol/kg）at a injection rate of 2 ml/s.Quantitative and qualitative evaluations were performed in blood perfusion of VX₂ carcinoma and normal hepatic parenchyma.Results The time of peak（TOP）and the time to peak（TIP）of perfusion in VX₂ carcinoma were shortened,the maximum signal reduction ratio(SRR_max)increased gradually and the mean transit time （MTI）elongated obviously with the increase of contrast medium concentration.MR perfusion in VX₂ carcinoma was characterized by early TOP（12.50s）,short TIP（7.50s）,satisfactory SRR_max（54.33%） and adequate MTY（35.00s）with the concentration of 0.20 mmol/kg.The TOP,TIP and MTT of VX₂ carcinoma were significantly different from those of normal hepatic parenchyma（P≤0.05）.Conclusion The 0.20 mmol/kg is the most optimized concentration for PWI of rabbits hepatic VX₂ carcinoma.更多还原