磁共振对比剂弛豫率研究及其在临床中的应用

Comparison of MRI contrast agents gadopentetate dimeglumine, gadodiamide and gadovist., their relaxation rates and effects on imaging

目的评价高浓度对比剂1．0mol／L钆布醇和标准浓度0．5mol／L钆喷酸葡胺在神经系统中的临床应用。方法采用GE公司SignaHDx3．0T成像设备，对制作的白蛋白溶液模体成像，评估三种对比剂弛豫率。复查脑组织有无感染的20位白血病患者，初次检查使用的对比剂为标准浓度0．5mol／L钆喷酸葡胺，复查使用的对比剂为高浓度对比剂1．0mol／L钆布醇。所有检查使用相同的成像序列。测量病灶和脑组织信噪比和对比噪声比，进行定量分析。结果随着三种对比剂剂量的变化，图像信号强度间差异无统计学意义（5．0g／L;P=0．35，6．5g／L：P=0．27，8．0g／L：P=0．23）。受检者先后使用两种对比剂成像，对比白质、灰质和血管的ROI区域的信噪比和对比噪声比，高浓度对比剂1．0mol／L钆布醇均高于标准浓度0．5mol／L钆喷酸葡胺（P值均〈0．05）。结论半剂量高浓度对比剂1．0mol／L钆布醇相对于标准浓度0．5mol／L钆喷酸葡胺有更好的强化效果。钆双胺、钆喷酸葡胺和钆布醇三种对比剂对不同浓度白蛋白溶液模体的弛豫率改变没有尊异。

Objective To evaluate the relaxation rates and imaging effects of three MRI contrast agents gadopentetate dimeglumine（0.5 mol/L）, gadodiamine and gadovist（1.0 mol/L） in the nervous system. Methods Relaxation rate differences between the three contrast agents were assessed using the GE Signa HDx 3.0 T MR scanner and phantom solutions of different albumin concentrations. Twenty leukemia patients whose initial scans had been conducted with the injection of a standard dose（0.5 mol/L）of gadopentetate dimeglumine as the contrast agent were recalled to have a follow-up scan for signs of brain infections with the same imaging protocols, except that a high concentration（1.0 mol/L）gadovist was used this time as the contrast agent. CNR and SNR in the ROI were measured for quantitative analysis. Results Changes in dosage of the three eontrast agents produced no difference in intensity of the image signal for each phantom solution of a specific albumin concentration（5.0 g/L ：P = 0.35,6.5g/L： P = 0.27,8.0 g/L： P = 0.23 ）. Two sets of scans of the leukemia patients showed that high concentration（1.0 mol/L）gadovist generated higher SNR and CNR in the ROI of the white matter, gray matter and vasculature than standard concentration（0.5 mol/L） gadopentetate dimeglumine（P〈 0.05）. Conclusions A half dose of high concentration（1.0 mol/L） gadovist generates better imaging enhancement than standard concentration（0.5 mol/L）gadopentetate dimegluminethe. Gadopentetate dimeglumine, gadodiamide and gadovist have no significant difference in relaxation rate.