Johansson Lars, Johnsson Cecilia, Penno Eva, Björnerud Atle, Ahlström Håkan
Department of Diagnostic Radiology, Uppsala University Hospital, Magnetkameran Ing 24, 751 85 Uppsala, Sweden.
Radiology. 2002 Oct;225(1):97-103. doi: 10.1148/radiol.2251010698.
To investigate the possibility of detecting cardiac transplant rejection and determining its degree of severity with magnetic resonance (MR) imaging with a blood pool contrast agent.
Rat allogeneic (PVG to Wistar/Kyoto, n = 9) and syngeneic (Wistar/Kyoto to Wistar/Kyoto, n = 6) heterotopic heart transplantations were performed. On the 2nd and 6th postoperative days, an ultrasmall superparamagnetic iron oxide, or USPIO, contrast agent was injected intravenously at a dose of 2 mg of iron per kilogram of body weight. The injection was followed by three-dimensional T1-weighted MR imaging of the heart grafts with an imaging time of approximately 2 minutes for each image for 44 minutes. The signal intensity (SI) was measured in the myocardium over time, and the relative enhancement was calculated. After the 6th day, the rats were sacrificed, and the morphology of the transplanted hearts was assessed histologically. The CIs for the difference of the means on day 2 and day 6 were calculated by using a bootstrap technique, and the correlation between the relative SI change and the histologically determined degree of rejection were calculated with the Spearman rank order correlation coefficient.
On day 6, a statistically significant difference between the groups was found at 4 minutes after injection of the contrast agent and increased with increasing time after injection. The mean percentage change in SI at the last time point for the allogeneic group on day 2 was -8.7% (SD, 8.5) and for the syngeneic group was -6.6% (SD, 6.0). On day 6, the allogeneic group had a relative SI change of 17.7% (SD, 8.7), whereas the syngeneic group had a change of -7.4% (SD, 2.6). There was a significant difference between only the two groups on day 6 (P <.001). Furthermore, in the allogeneic group the histologically determined degree of rejection correlated positively with the relative SI enhancement (r = 0.89, P <.005).
Acutely rejecting heart transplants can be distinguished from nonrejecting ones in an animal model with MR imaging and a blood pool contrast agent. In addition, the relative SI enhancement reflects the histologically determined degree of rejection.
探讨利用血池造影剂通过磁共振成像（MR）检测心脏移植排斥反应并确定其严重程度的可能性。
进行大鼠同种异体（从PVG到Wistar/Kyoto，n = 9）和同基因（从Wistar/Kyoto到Wistar/Kyoto，n = 6）异位心脏移植。在术后第2天和第6天，以每千克体重2毫克铁的剂量静脉注射超小型超顺磁性氧化铁（USPIO）造影剂。注射后对心脏移植物进行三维T1加权MR成像，每个图像的成像时间约为2分钟，共持续44分钟。随时间测量心肌的信号强度（SI），并计算相对增强率。在第6天后，处死大鼠，通过组织学评估移植心脏的形态。使用自助法技术计算第2天和第6天均值差异的置信区间（CI），并使用Spearman等级相关系数计算相对SI变化与组织学确定的排斥程度之间的相关性。
在第6天，注射造影剂后4分钟时发现两组之间存在统计学显著差异，且随着注射后时间的增加而增大。第2天同种异体组在最后一个时间点的SI平均百分比变化为-8.7%（标准差，8.5），同基因组为-6.6%（标准差，6.0）。在第6天，同种异体组的相对SI变化为17.7%（标准差，8.7），而同基因组的变化为-7.4%（标准差，2.6）。仅在第6天两组之间存在显著差异（P <.001）。此外，在同种异体组中，组织学确定的排斥程度与相对SI增强呈正相关（r = 0.89，P <.005）。
在动物模型中，使用MR成像和血池造影剂可以将急性排斥的心脏移植与非排斥的区分开来。此外，相对SI增强反映了组织学确定的排斥程度。
Zotero 插件