A STUDY OF INTRATUMORAL DISTRIBUTION OF Gd-DTPA ON DYNAMIC MRI

1)目的是在动态mri上明确Gd-DTPA在肿瘤内的分布。2)实验研究：a)在兔VX2肿瘤的研究中，Gd-DTPA在肿瘤内的浓度变化与肿瘤周围及正常组织有明显差异。说明动态MRI反映了包括肿瘤在内的各种组织的血管通透性差异，有助于组织特征的诊断。在一项使用切除的含癌人肺标本的研究中，Gd-DTPA在肿瘤中的浓度变化与术前MRI上肿瘤的信号强度变化一致，并且在坏死组织中也显示低浓度的Gd-DTPA。3)临床研究：在T1加权动态研究肺癌的时间-强度曲线分析中，肺癌的信号强度在注射造影剂后3-10分钟迅速升高，达到峰值，到注射造影剂后30分钟逐渐下降。Gd-DTPA增强MRI可用于肺癌继发性改变的肿瘤范围诊断、结核瘤的鉴别诊断、保守治疗后的治疗效果、放射性肺炎复发的诊断。对于肝细胞癌的诊断，动态MRI的总体准确性优于常规T2加权图像，尤其是对治疗效果和复发的诊断。4)结论：实验和临床通过动态MRI研究Gd-DTPA在肿瘤内及肿瘤周围的分布。动态MRI是诊断肿瘤生存能力的一种非常有用的方法。而Gd-DTPA对肿瘤的染色主要取决于血管的通透性。肿瘤特异性造影剂的研究至关重要。

1)The purpose was to clarify the intratumoral distibution of Gd-DTPA on dynamic MRI.2)Experimental study : a)In a study using rabbit VX2 tumor, alteration of Gd-DTPA concentration in the tumor revealed significantly different from that around tumor and from that of normal tissue. The result meant that dynamic MRI reflected the difference of vascular permeability of various tissues including tumor and that dynamic MRI contributed to the diagnosis of tissue characteristics.In a study using resected human lung specimen containing cancer, alteration of Gd-DTPA concentration in the tumor revealed pararell to that of signal intensity of the tumor on MRI taken preoperatively, and also revealed low concentration of Gd-DTPA in the necrotic tissue.3)Clinical Study : In a time-intensity curve analysis of lung cancer on the T1 weighted dynamic study, signal intensity of the lung cancer showed a rapid increase and reached the peak at the time of 3-10 minutes and showed gradual decrease to the time of 30 minutes after injection of contrast medium. Gd-DTPA enhanced MRI was useful in the diagnosis of tumor extent of lung cancer with secondary change, differential diagnosis of tuberculoma, therapeutic effect after conservative therapy, diagnosis of recurrence from radiation pneumonitis. As for diagnosis for hepatocellular carcinoma, over all accuracy of dynamic MRI revealed superior to that of conventional T2 weighted images especially in the diagnosis of therapeutic effect and recurrence.4)Conclusion : We studied the distribution of Gd-DTPA in and around the tumor on dynamic MRI experimentally and clinically. Dynamic MRI was a very useful modality to diagnose tumor viability. However, tumor stain by Gd-DTPA mainly depends on the vascular permeability. Research of tumor specific contrast media is essential.