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

2)实验研究：a)在兔VX2肿瘤的研究中，肿瘤内Gd-DTPA浓度的变化与瘤周及正常组织的浓度变化有显著差异。结果表明，动态MRI反映了包括肿瘤在内的不同组织血管通透性的差异，动态MRI有助于组织特征的诊断。在一项以切除的含癌肺标本为研究对象的研究中，肿瘤内Gd-DTPA浓度的变化与术前MRI上肿瘤信号强度的变化平行，同时也显示了坏死组织中Gd-DTPA的低浓度。3)临床研究：在对肺癌进行时间-强度曲线分析的T1加权动态研究中，肺癌的信号强度在注射造影剂后3~10min时迅速增加，并达到峰值，至30min时信号强度逐渐降低。Gd-DTPA增强MRI对诊断肺癌继发病变的肿瘤范围、结核球的鉴别诊断、保守治疗后的疗效、放射性肺炎复发的诊断有重要价值。对于肝细胞癌的诊断，动态MRI的总体准确率优于常规T2加权像，尤其在疗效和复发的诊断上。4)结论：我们从实验和临床两方面研究了Gd-DTPA在动态MRI上的分布。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是非常必要的。

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.