in-vivo microCT for imaging of small animals and specimens

我们申请在临床前生物医学研究中用于非侵入性解剖和功能成像的活体小动物微型CT，以取代目前在大学医学中心哥廷根(UMG)运行的唯一体内微型CT。这确保了UMG完善的基于X射线的活体成像平台得到进一步开发，并考虑到与动物福利有关的方面，为尽可能多的工作组的科学项目提供该平台。这既包括基础研究领域，如转基因小鼠的体内表型，活体动物耳蜗内植入的准确位置的表示，以及通过测量随着时间的推移肿瘤体积对肿瘤学新治疗方法的评估。新系统还将允许进一步使用UMG开发的基于X射线的肺功能测量技术。它将被用于监测疾病进展，并评估新疗法的有效性，不仅适用于肿瘤，也适用于肺部、传染病和代谢性疾病。体内微型CT系统的设计相当于临床CT的设计，即被检查动物躺在检查台上，而X射线管和探测器进行联合旋转。与临床CT相比，MicroCT系统更小，通常被设计为全面保护系统，以确保辐射安全。此外，它在小于100微米的范围内实现了更高的空间分辨率，这是小鼠、大鼠、斑马鱼等实验动物由于体积小而需要的。与需要更高分辨率才能详细显示体外样本的“普通”MicroCT相比，体内MicroCT的记录时间非常短，辐射剂量很低，因此在动物保护的3R概念意义上，可以随时间纵向监测活动物(在麻醉下)。这样，解剖特征和功能信息可以在不同的时间非侵入性和动物友好地获得，从而在各自的研究项目中最大限度地获得知识。扫描时间短，平均分辨率约为20微米可以实现，这使得在体微CT可以应用于组织样本的3D表示，在快速“筛选”的意义上，这一过程在传统的微CT中是不可能的，因为测量时间非常长。目前的体内MicroCT已经成功地用于各种体外研究，如分析CAM分析(鸡绒毛膜-尿囊膜)和大量人类牙齿的数字化。后者可以优化有关根管充填的研究。

We apply for an in-vivo small animal microCT for non-invasive anatomical and functional imaging in preclinical biomedical research, to replace the only in-vivo microCT currently operated at the University Medical Center Göttingen (UMG). This ensures that the well-established X-ray-based in-vivo imaging platform at the UMG is further developed and that it is made available to as many working groups as possible for their scientific projects, taking into account aspects relevant to animal welfare. This includes both the area of basic research such as the in-vivo phenotyping of transgenic mice, the representation of the exact position of the cochlear implants within the cochlea in living animals and the evaluation of new therapy methods in oncology by measuring tumor volumes over time. The new system would also allow further use of the X-ray-based lung function measurement technique developed at the UMG. It will be used to monitor disease progression and evaluate the effectiveness of new therapies not only for tumors but also for lung, infectious and metabolic diseases. The design of an in-vivo microCT system corresponds to that of a clinical CT, i.e. the animal to be examined rests on an examination table while the X-ray tube and detector perform a combined rotation. In contrast to the clinical CT, microCT systems are smaller and typically designed as a full protection systems to ensure radiation safety. In addition, it achieves a higher spatial resolution in the range of less than 100 µm, which is required for experimental animals such as mice, rats, zebrafish, etc. due to their small size. In contrast to a "normal" microCT, in which significantly higher resolutions are needed for the detailed display of ex-vivo samples, the recording times in the in-vivo microCT are very short and the radiation dose low, so that living animals (under anesthesia) can be monitored longitudinally over the time, in the sense of the 3R concept of animal protection. In this way, anatomical features and functional information are obtained non-invasively and animal-friendly at different times for maximum gain of knowledge in the respective research project. The short scanning times and the average resolution of approx. 20 µm that can be achieved allow the in-vivo microCT to be applied for the 3D representation of tissue samples in the sense of a quick “screening”, a procedure which otherwise in a classic microCTs would be impossible due to the very long measurement times. The current in-vivo microCT has already been used successfully in large variety of ex-vivo studies such as for the analysis of CAM assays (chick chorio-allantoic membrane) and for the digitization of a large number of human teeth. The latter allows optimization of studies on root canal filling.