Small animal computed tomography (µCT)
Computed tomography is basically based on the X-ray method. However, while objects with low absorption cannot be recognized with X-rays if they are covered by objects with high absorption, CT solves this problem by rotating the X-ray source and detector around the object being examined and taking several hundred images. However, only one thin layer (slice) of the body is examined at a time and these images are combined in the computer. Only the combination of all the images produces an image of the slice (reconstruction). From the individual slices, 3-dimensional information can be obtained about the course of vessels, the shape of organs and the position of organs. To examine larger regions, the object to be examined must be moved through the device piece by piece. The organs to be examined can be displayed in any projection. The organs to be examined can be displayed individually. This not only requires a lot of programming and computing power, it also requires a great deal of experience on the part of the examiner to determine how to recognize certain tissue types and how to recognize a particular organ.
- Advantages:
Even small objects with low contrast can be recognized. The resolution can be very high and depends on the number of images and slices. (Time and dose factor). - Limitations:
Problems with some tissues, changes in soft tissues with a high water content, e.g. inflammation in the brain. Problem: Radiation exposure, especially in longitudinal studies.