What Is a Micro CT?
Micro CT is a technique that non-destructively generates three-dimensional internal images.
Conventional CT is commonly employed in fields such as medicine, primarily for observing the internal structures of large objects like humans. Micro CT, on the other hand, is used to visualize intricate structures of small objects, particularly solid and biological samples, in high resolution.
A significant feature of Micro CT is its ability to investigate internal structures without damaging the sample. It proves highly valuable for material quality assessment and the study of biological specimens. Moreover, it enables the collection of data in a relatively short time, facilitating the swift construction of images.
Uses of Micro CT
Micro CT finds applications in various fields. Here are some examples of its uses:
1. Materials Research
Due to its ability to investigate the internal structure of materials with very high resolution, Micro CT is widely utilized in materials research. It can detect features like crystal structures in metal alloys and tiny defects within materials. Additionally, it can investigate the distribution and orientation of fibers in composite materials like fiber-reinforced plastics, contributing to the enhancement of material performance.
2. Biomedical Sciences
Micro CT is employed in non-invasive anatomical studies of biological specimens. In the field of orthopedics, for instance, it is extensively used for researching internal bone structures, bone density, and bone metabolism. It is also used to investigate details of organs like the brain and heart in animal experiments, contributing to disease research.
3. Archival Preservation
In the preservation of cultural heritage and artworks, Micro CT is crucial for non-destructive analysis. It is used to protect valuable art pieces and historical objects. By examining the detailed internal structures of paintings and sculptures, aids in replication and restoration efforts.
4. Entomology
In entomological research, Micro CT proves highly useful. It is employed to study the exoskeleton and internal organs of insects, contributing to insect species identification, classification, and ecological studies.
Principles of Micro CT
Micro CT generates X-ray beams from a high-energy X-ray tube. The sample is mounted on a rotating stage that revolves 360 degrees, placing it in front of the X-ray beam. The X-ray beam emitted from the source passes through the sample, and the X-ray transmission rate is measured by a detector.
As the X-ray beam reaches the detector from various parts within the sample, the attenuation of each X-ray beam differs based on the variations in transmission rates. Since the sample is mounted on a rotating stage, it can rotate 360 degrees. Therefore, the X-ray beam is projected onto the sample from various angles, and X-ray transmission rate data is collected at each angle.
The X-ray transmission rate data at each angle is transmitted to the computer and stored. The computer software reconstructs the internal structure of the sample from the collected transmission rate data. This enables the visualization and analysis of the internal structure of the sample in three-dimensional data, allowing for detailed examination.
How to Choose Micro CT
Several essential factors need consideration when choosing a Micro CT. Here are some selection criteria:
1. Temporal Resolution
Temporal resolution refers to the time it takes for a Micro CT to scan a single sample and acquire image data. It is crucial for applications that require fast data acquisition.
Products with high temporal resolution enable rapid data acquisition, generating a series of images at short intervals. On the other hand, products with low temporal resolution take longer to scan, making them less suitable for observing dynamic samples.
2. Spatial Resolution
Spatial resolution in Micro CT images indicates how small each pixel can represent a physical size. High spatial resolution is vital for analyzing fine structures and intricate features. It depends on the performance of the X-ray source and detector. Using high-energy X-ray sources and high-performance detectors allows achieving high spatial resolution.
3. Sample Loading Weight
Sample loading weight is the maximum weight of samples that a Micro CT system can handle. The choice depends on factors such as sample size, shape, and density. If scanning large samples or high-density metal specimens is required, a product with a high sample loading weight is necessary.