Spinal cord injury (SCI) leads to severe dysfunction below injured segment and poses a great pressure to the individual and society. In this study, we applied ¹⁸F-alfatide II positron emission tomography/computed tomography (PET/CT) to monitor angiogenesis in an SCI model after estrogen (E2) treatment, as well as to evaluate the prognosis in a noninvasive manner. The SCI model was established with male rats and the rats were randomly divided into E2-treated group (SCI + E2) and E2-untreated group (SCI). Sham group was also used as control (Sham). The angiogenesis after SCI was monitored by ¹⁸F-alfatide II PET/CT and verified by immunofluorescence of CD31 and CD61. We also evaluated the level of E2 and growth-associated protein 43 (GAP43) by enzyme-linked immunosorbent assay. Finally, Basso, Beattie, and Bresnahan (BBB) scores were determined to evaluate the exercise capacity of the rats in all 3 groups. Our results showed that the BBB score of SCI + E2 group was significantly different from that of SCI group (P < .05) and Sham group (P < .01). The uptake of ¹⁸F-alfatide II was positively correlated with the expression level of GAP43, both of which reached the peak at day 7 after injury. CD31 and CD61 immunostaining further verified increased angiogenesis in E2-treated SCI lesions. We concluded that ¹⁸F-alfatide II PET/CT can monitor the angiogenesis status after SCI in vivo and it may help clinician predict the progression of patients with SCI. This may benefit the study of vascular repair after SCI and provide a tool for evaluation of SCI treatment in clinical practices.

脊髓损伤（SCI）会在受伤部位以下导致严重功能障碍，并给个人和社会带来巨大压力。在这项研究中，我们应用¹⁸ F-alfatide II正电子发射断层扫描/计算机断层扫描（PET / CT）来监测雌激素（E2）治疗后SCI模型中的血管生成，并以无创方式评估预后。用雄性大鼠建立SCI模型，将大鼠随机分为E2治疗组（SCI + E2）和E2未治疗组（SCI）。假手术组也用作对照（假手术）。SCI后的血管生成由¹⁸F-alfatide II PET / CT，并通过CD31和CD61的免疫荧光验证。我们还通过酶联免疫吸附试验评估了E2和生长相关蛋白43（GAP43）的水平。最后，确定Basso，Beattie和Bresnahan（BBB）评分以评估所有3组大鼠的运动能力。我们的结果表明，SCI + E2组的BBB评分与SCI组（P <.05）和Sham组（P <.01）显着不同。摄取¹⁸ F-alfatide II与GAP43的表达水平呈正相关，二者在损伤后第7天达到峰值。CD31和CD61免疫染色进一步证实了E2治疗的SCI病变中血管生成的增加。我们得出的结论是¹⁸F-alfatide II PET / CT可以监测体内SCI后的血管生成状态，这可能有助于临床医生预测SCI患者的病情。这可能有益于SCI后的血管修复研究，并为临床实践中评估SCI治疗提供了一种工具。