in-vivo microCT for imaging of small animals and specimens

点击翻译按钮获取中文摘要

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.