Mn-DPDP增强MRI胰腺强化特征以及与Gd-DTPA动态增强MRI比较的初步研究

Preliminary Study of Pancreatic Enhancement Characteristics on MRI──A Comparison of Mn-DPDP with Gd-DTPA

目的 探讨Mn DPDP增强MRI胰腺强化特征 ,并与Gd DTPA动态增强比较 ,为Mn DPDP增强胰腺MRI的临床应用提供指导。资料与方法 46例患者因肝脏局灶病变行Gd DTPA动态增强和Mn DPDP增强MRI,其中 2 9例图像及临床病史无胰腺病变者入选本研究。常规平扫及Gd DTPA动态增强 ;次日经肘静脉缓慢滴注Mn DPDP(0 .5ml/kg体重 ) ,于给药结束后 5～ 40min内每 5min以及 2 4h行SET1W及SPGRT1W扫描。结果 正常胰腺于注药结束后 5min即强化 (SNR高于平扫 ,P <0 .0 5 ) ,5～ 40min维持于一平台期 ,胰腺信号强度于 35min达到最大 ,SET1W及SPGRT1W图像上强化指数 (CEI)分别为 74%± 36和 80 %± 2 9(两者间差别无统计学意义 ,P >0 .0 5 ) ;2 4h胰腺SNR仍较平扫高 (P <0 .0 5 )。给药结束后 35minSPGRT1W图像上胰腺CEI(80 %± 2 9)低于Gd DTPA动态增强动脉期 (10 8%± 2 6 ) (P <0 .0 5 ) ,与门脉期的 85 %± 2 5相似 (P >0 .0 5 ) ,比延迟期的 6 9%± 13高 (P <0 .0 5 )。结论 正常胰腺Mn DPDP增强扫描显著强化 ,能达到Gd DTPA动态增强门脉期胰腺强化程度 ,并能提供充裕的扫描时间窗及可采用除SPGRT1W序列外SET1W序列扫描。

Objective To investigate the enhancement characteristics of the pancreas on Mn DPDP enhanced MRI and to compare Mn DPDP enhancement with Gd DTPA dynamic enhancement, to guide Mn DPDP enhanced pancreatic MRI in clinical practice.Materials and Methods During sep. 1999～March 2000, Gd DTPA and Mn DPDP enhanced MRI were carried out in 46 patients with focal hepatic lesions, of which 29 cases had no evidence of pancreatic disease and were enrolled in this study. Conventional plain and dynamic Gd DTPA enhanced scanning were done initially. On the next day, SE T 1WI and SPGR T 1WI were performed at every 5 min. interval in the first 40 minutes and at 24 hours after the administration of Mn DPDP, with a dose of 0.5ml/kg and at a rate of 2～3ml/min, was finished.Results The normal pancreas showed enhancement at 5 min. after the administration of Mn DPDP with a significant increase on SNR (P<0.05), and was kept in a platform phase for 5 to 40 min. At 35 min. the contrast enhancement index (CEI) of pancreas reached its peak of 74%±36 and 80%±29 on SE T 1WI and SPGR T 1WI, respectively, but no significant difference between the two sequences was seen. After 24 hours, the SNR of pancreas was still higher than that on plain images. The pancreatic CEI on SPGR T 1WI, obtained at 35 min after the administration of Mn DPDP, was lower than that obtained on Gd DTPA enhanced images in arterial phase (80%±29 vs 108%±26, P<0.05). But it was similar to that obtained in portal phase (85%±25, P<0.05) and higher than that obtained in delayed phase (69%±13, P<0.05).Conclusion Mn DPDP enhanced MRI can be used for studying the pancreas as its efficacy of enhancement is compatible to that of Gd DTPA in portal phase, it can also provide plentiful imaging time windows and adopt other SE T 1WI sequences besides SPGR T 1WI.