Clinic for Oral and Maxillofacial Surgery and Plastic Surgery, University Medical Center of the Johannes Gutenberg University Mainz, Augustusplatz 2, 55131, Mainz, Germany.
Molecular and Cellular Imaging, Comprehensive Heart Failure Center, University Hospital Würzburg, Josef-Schneider-Strasse 2, 97080, Würzburg, Germany.
Clin Oral Investig. 2021 Oct;25(10):5843-5854. doi: 10.1007/s00784-021-03889-6. Epub 2021 Mar 30.
Micro-computed tomography (μ-CT) and histology, the current gold standard methods for assessing the formation of new bone and blood vessels, are invasive and/or destructive. With that in mind, a more conservative tool, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), was tested for its accuracy and reproducibility in monitoring neovascularization during bone regeneration. Additionally, the suitability of blood perfusion as a surrogate of the efficacy of osteoplastic materials was evaluated.
Sixteen rabbits were used and equally divided into four groups, according to the time of euthanasia (2, 3, 4, and 6 weeks after surgery). The animals were submitted to two 8-mm craniotomies that were filled with blood or autogenous bone. Neovascularization was assessed in vivo through DCE-MRI, and bone regeneration, ex vivo, through μ-CT and histology.
The defects could be consistently identified, and their blood perfusion measured through DCE-MRI, there being statistically significant differences within the blood clot group between 3 and 6 weeks (p = 0.029), and between the former and autogenous bone at six weeks (p = 0.017). Nonetheless, no significant correlations between DCE-MRI findings on neovascularization and μ-CT (r =-0.101, 95% CI [-0.445; 0.268]) or histology (r = 0.305, 95% CI [-0.133; 0.644]) findings on bone regeneration were observed.
These results support the hypothesis that DCE-MRI can be used to monitor neovascularization but contradict the premise that it could predict bone regeneration as well.
微计算机断层扫描（μ-CT）和组织学是评估新骨和血管形成的当前金标准方法，但这些方法具有侵袭性和/或破坏性。考虑到这一点，我们测试了一种更保守的工具，即动态对比增强磁共振成像（DCE-MRI），以评估其在监测骨再生过程中新生血管形成的准确性和可重复性。此外，还评估了血液灌注作为骨形成材料疗效的替代指标的适用性。
使用 16 只兔子，根据安乐死时间（手术后 2、3、4 和 6 周）将它们平均分为四组。将动物进行两次 8mm 颅骨切开术，并用血液或自体骨填充。通过 DCE-MRI 对动物进行体内新生血管评估，通过 μ-CT 和组织学对动物进行体外骨再生评估。
可以通过 DCE-MRI 一致地识别出这些缺陷，并测量其血液灌注情况，在血凝块组中，3 周到 6 周之间（p=0.029）以及与自体骨在 6 周之间（p=0.017）存在统计学显著差异。尽管如此，DCE-MRI 检测到的新生血管与 μ-CT（r=-0.101，95%CI[-0.445;0.268]）或组织学（r=0.305，95%CI[-0.133;0.644]）检测到的骨再生之间没有显著相关性。
这些结果支持 DCE-MRI 可用于监测新生血管形成的假设，但与 DCE-MRI 可预测骨再生的前提相矛盾。
