Wang J J, Hendrich K S, Jackson E K, Ildstad S T, Williams D S, Ho C
Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pennsylvania, USA.
Kidney Int. 1998 Jun;53(6):1783-91. doi: 10.1046/j.1523-1755.1998.00945.x.
The purpose of this study was to determine the feasibility of using quantitative magnetic resonance imaging (MRI) with non-invasive arterial spin labeling to assess perfusion of transplanted kidneys in rats. MRI studies were performed on five groups of rats: normal Fisher 344 rats, Fisher 344 rats that had received a syngeneic kidney transplant either 3 or seven days prior to study, and Fisher 344 rats that had received an allogeneic kidney (ACI rat as the donor) either three or seven days prior to study. The contralateral native kidney remained in place for comparison. Cortical perfusion was quantitated from a slice through the center of each kidney in anesthetized rats at 4.7 Tesla with a fast gradient-echo MRI sequence following the arterial spin labeling. The spin-lattice relaxation time was measured within the cortex, and the cross sectional area of the kidney was also determined within the same MRI plane. Immediately after the perfusion imaging measurement, transplanted kidneys were removed and scored for rejection using the Banff histological criteria. Renal cortical perfusion in normal kidneys was 7.5 +/- 0.8 ml/g/min (N = 12 rats, 24 kidneys). At the third day post-transplantation, that is, before marked acute rejection, the renal cortical perfusion rate was similar in both syngeneic and allogeneic kidneys [3.3 +/- 1.7 (N = 6) and 3.0 +/- 2.4 ml/g/min (N = 6), respectively]. In contrast, at the seventh day post-transplantation, that is, during severe rejection, the renal cortical perfusion rate in allogeneic kidneys was very low (undetectable) compared to the value in syngeneic kidneys [that is, < or = 0.3 (N = 6) versus 5.2 +/- 2.0 ml/g/min (N = 6), respectively]. Moreover, the renal cortical perfusion rate determined by MRI was significantly (P < 0.05, r = -0.82) correlated with histological rejection. We conclude that the quantitative measurement of renal cortical perfusion by MRI with arterial spin-labeling could provide a non-invasive diagnostic method for monitoring the status of renal transplants without requiring the administration of a contrast agent.
本研究的目的是确定使用定量磁共振成像（MRI）结合非侵入性动脉自旋标记来评估大鼠移植肾灌注的可行性。对五组大鼠进行了MRI研究：正常的Fisher 344大鼠、在研究前3天或7天接受同基因肾移植的Fisher 344大鼠，以及在研究前3天或7天接受异基因肾（供体为ACI大鼠）的Fisher 344大鼠。保留对侧天然肾作为对照。在麻醉的大鼠中，于4.7特斯拉下，采用快速梯度回波MRI序列，在动脉自旋标记后，从穿过每个肾脏中心的切片定量皮质灌注。在皮质内测量自旋晶格弛豫时间，并在同一MRI平面内确定肾脏的横截面积。在灌注成像测量后立即取出移植肾，并使用Banff组织学标准对排斥反应进行评分。正常肾脏的肾皮质灌注为7.5±0.8 ml/g/min（N = 12只大鼠，24个肾脏）。移植后第3天，即在明显的急性排斥反应之前，同基因和异基因肾脏的肾皮质灌注率相似[分别为3.3±1.7（N = 6）和3.0±2.4 ml/g/min（N = 6）]。相比之下，移植后第7天，即在严重排斥反应期间，异基因肾脏的肾皮质灌注率与同基因肾脏相比非常低（无法检测到）[即分别为≤0.3（N = 6）与5.2±2.0 ml/g/min（N = 6）]。此外，MRI测定的肾皮质灌注率与组织学排斥反应显著相关（P < 0.05，r = -0.82）。我们得出结论，通过MRI结合动脉自旋标记对肾皮质灌注进行定量测量，可以提供一种无需注射造影剂的非侵入性诊断方法，用于监测肾移植状态。
