目的：比较钆塞酸二钠（Gd-EOB-DTPA）及钆喷酸葡胺（Gd-DTPA）肝脏 MR动态增强扫描腹腔脏器及血管的强化特点，重点比较Gd-EOB-DTPA移行期与Gd-DTPA平衡期的图像特点。方法：本研究为前瞻性、个体内随机对照研究。25例病理证实为原发直肠癌或结肠癌、怀疑肝转移的患者，3天内行2次肝脏 MR 动态增强检查，分别使用 Gd-EOB-DTPA及Gd-DTPA两种对比剂。动态增强扫描的序列相同，包括平扫、动脉期、门静脉期、平衡期（Gd-DTPA）／移行期（Gd-EOB-DTPA）。图像客观评估中，测量各期相图像上血管及肝脾实质的信号强度。以椎旁肌肉的信号为参考，计算相对信号强度（RS）并比较两组间的差异，以及不同期相时肝实质RS的差异。主观评估：读片者主观评价增强扫描各期相图像上，主动脉、门静脉及肝静脉与肝实质的相对信号强度。结果：肝实质的RS：在动脉期Gd-DTPA 组明显高于Gd-EOB-DTPA组（t＝3．006，P＝0．005）；在门静脉期及平衡期／移行期，两组检查的差异无统计学意义（t＝1．788，P＝0．086；t＝0．781，P＝0．442）。Gd-EOB-DTPA检查时，门静脉期肝实质RS明显高于动脉期（t＝－3．014，P＝0．006），移行期RS与门静脉期的差异无统计学意义。Gd-DTPA检查时，平衡期肝实质RS明显低于门静脉期（t＝5．827，P＝0．000）。主观评估：Gd-DTPA增强扫描平衡期图像上所有患者的主动脉、门静脉、肝静脉均为高信号（100％）；Gd-EOB-DTPA 增强扫描移行期图像上主动脉、门静脉、肝静脉均以低或等信号为主（84％，92％，92％）。结论：Gd-EOB-DTPA动态增强 MR 检查，肝脏实质在门静脉期及移行期呈持续强化，其移行期的图像特征与Gd-DTPA平衡期的图像特征有明显不同，在影像诊断时应予以关注。%Objective:To compare the imaging feature of dynamic contrast enhanced liver MR imaging by gadoxetate disodium (Gd-EOB-DTPA)and gadopentetate dimeglumine (Gd-DTPA).Methods:Twenty-five patients suspected of liver metastases from colorectal cancer underwent twice MR examinations on 3 .0T scanner using the contrast agent of Gd-EOB-DTPA (0.05mmol/kg)and Gd-DTPA (0.1mmol/kg)respectively.Pre- and post- dynamic contrast enhanced images were acquired,including arterial phase (AP),portal venous phase (PP),equilibrium phase (EP for Gd-DTPA)/transitional phase (TP for Gd-EOB-DTPA).On images of all phases,signal intensity of abdominal organs (liver and spleen)and vessels (aor-ta,inferior vena cava,portal vein,hepatic vein)were measured,and signal intensity of paravertebral muscle was measured as reference.Relative signal intensity (RS)were calculated and compared between the two groups using the two types of con-trast media.The image features of contrast enhanced images were also subjectively evaluated.Results:There was statistically significant difference in RS of liver on AP images between the two groups (t= 3.006,P= 0.005).There was no statistically significant difference in RS of liver on EP and TP images between the two groups.In Gd-EOB-DTPA group,liver RS on PP images was much higher than that on AP images (t= -3.014,P= 0.006),and on TP images,liver RS was lower than that on PP images but without statistic difference.In Gd-DTPA group,liver RS was much lower on EP images than that on PP images (t= 5.827,P= 0.000).In subjective evaluation,aorta,portal vein and hepatic vein of all patients were hyperintense on EP images in Gd-DTPA group;whereas in Gd-EOB-DTPA group,aorta,portal vein and hepatic vein were mainly hypo-or iso-intense images (84%,92%,92%).Conclusion:In Gd-EOB-DTPA dynamic contrast enhanced MRI,liver parenchyma was continuously enhanced during portal venous phase and transitional phase.The image features in equilibrium phase of Gd-DTPA enhanced scan are quite different from transitional phase of Gd-EOB-DTPA enhanced scan,which should be con-sidered in diagnosis.
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