Song Dandan, Shujaat Sohaib, Zhao Ruiting, Huang Yan, Shaheen Eman, Van Dessel Jeroen, Orhan Kaan, Vande Velde Greetje, Coropciuc Ruxandra, Pauwels Ruben, Politis Constantinus, Jacobs Reinhilde
OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium.
Department of Dentomaxillofacial Radiology, Faculty of Dentistry, University of Ankara, Ankara, Turkey.
Imaging Sci Dent. 2020 Sep;50(3):199-208. doi: 10.5624/isd.2020.50.3.199. Epub 2020 Sep 16.
This study was performed to introduce an hybrid multimodality technique involving the coregistration of micro-computed tomography (micro-CT) and high-resolution magnetic resonance imaging (HR-MRI) to concomitantly visualize and quantify mineralization and vascularization at follow-up in a rat model.
Three adult female rats were randomly assigned as test subjects, with 1 rat serving as a control subject. For 20 weeks, the test rats received a weekly intravenous injection of 30 µg/kg zoledronic acid, and the control rat was administered a similar dose of normal saline. Bilateral extraction of the lower first and second molars was performed after 10 weeks. All rats were scanned once every 4 weeks with both micro-CT and HR-MRI. Micro-CT and HR-MRI images were registered and fused in the same 3-dimensional region to quantify blood flow velocity and trabecular bone thickness at T0 (baseline), T4 (4 weeks), T8 (8 weeks), T12 (12 weeks), T16 (16 weeks), and T20 (20 weeks). Histological assessment was the gold standard with which the findings were compared.
The histomorphometric images at T20 aligned with the HR-MRI findings, with both test and control rats demonstrating reduced trabecular bone vasculature and blood vessel density. The micro-CT findings were also consistent with the histomorphometric changes, which revealed that the test rats had thicker trabecular bone and smaller marrow spaces than the control rat.
The combination of micro-CT and HR-MRI may be considered a powerful non-invasive novel technique for the longitudinal quantification of localized mineralization and vascularization.
本研究旨在介绍一种混合多模态技术，该技术涉及微型计算机断层扫描（micro-CT）与高分辨率磁共振成像（HR-MRI）的配准，以在大鼠模型随访时同时可视化和量化矿化与血管生成情况。
将三只成年雌性大鼠随机指定为受试对象，一只大鼠作为对照。在20周内，受试大鼠每周静脉注射30μg/kg唑来膦酸，对照大鼠给予相似剂量的生理盐水。10周后双侧拔除下颌第一和第二磨牙。所有大鼠每4周用micro-CT和HR-MRI各扫描一次。将micro-CT和HR-MRI图像在同一三维区域进行配准和融合，以量化T0（基线）、T4（4周）、T8（8周）、T12（12周）、T16（16周）和T20（20周）时的血流速度和小梁骨厚度。组织学评估作为金标准用于比较研究结果。
T20时的组织形态计量学图像与HR-MRI结果一致，受试大鼠和对照大鼠的小梁骨脉管系统和血管密度均降低。micro-CT结果也与组织形态计量学变化一致，显示受试大鼠的小梁骨比对照大鼠更厚，骨髓腔更小。
micro-CT和HR-MRI的联合应用可被视为一种强大的非侵入性新技术，用于局部矿化和血管生成的纵向量化。
