Scanco µCT-40 Extremely High Resolution
Computed Tomography Cabinet System
PI: Dr. Neil Sharkey
Location: Room 40A Recreation Bldg.
Scheduling and Technical Contact: Nick Giacobe
The Scanco µCT 40 can generate high resolution CT images for samples as large as 30mm x 100mm. Standard resolution scans in the sample tube size have an approximate resolution of 20µm. Smaller samples can be scanned in a 10mm tube, for a resolution of 10µm. This system allows for researchers to generate high quality images of tissue samples to evaluate tissue density and histological properties.
Technical Specifications
Type: Desktop Cone-Beam MicroCT Scanner
X-Ray: Microfocus X-Ray-source
5 or 7 µm spot size
30-70 kVp / 20-50 keV (160 µA)
No shielding required
Detector: 2048×256 elements, 24 µm pitch
Resolution: 6-72 µm nominal isotropic, 9 µm (10% MTF)
Image matrix: 512×512, 1024×1024 or 2048×2048 Pixels
Specimen Size: FOV 12 to 36.9 mm max. Scan Length 80 mm
Information from website.
Software Capabilities
The interface of the system is the DEC Alphastation using OpenVMS and Scanco’s data acquisition and analysis software. The DEC Alphastation uses 64 bit software to allow for the handling of the extremely large data files that are generated by the scanner. File sizes can be as large as 8 MB per slice. That means a 1000 slice scan would be approximately 8 GB. That’s an extremely large file.
The Scanco software handles the interface to the scanner for data acquisition. The software can be set for multiple scans per sample tube in batch mode. This allows for several scans to be configured in batch for overnight scanning and reconstruction. Interactive (non-batch) scanning is also an option for smaller scans.
Scanco’s software allows for sophisticated 2D and 3D histological evaluations. The user can carve out or “contour” Regions of Interest in several non-adjacent 2-D slices and “morph” to interpolate the changes between those slices. This means that a 3-D Volume of Interest can be created quickly. A 3-D histological evaluation can be performed within the software. A 3-D visualization and rendering tool allows the user to see a 3-D representation of the scanned sample. Of course, data can be copied from the system to personal computers for additional or more specific evaluations with other software packages.
Local Enhancements and Applications
One of the challenges that had to be overcome for the Mouse Bone Genetics project was to scan many small bones simultaneously. With approximately 5,000 specimens to evaluate, it would take a team many years working around the clock to finish if only one bone per sample tube could be scanned. The only way to accomplish the task more reasonably was to reduce the scanning time by increasing the number of samples per scan.
Denny Ripka, and his predecessor Doug Tubbs, fabricated stacking sample carriers. The first generation carrier had four holes, and could be stacked three carriers high. This allowed for 12 samples per scanning session, at standard resolution. Later enhancements to the carriers included a rod to align the carriers together and orientation holes that show up on the scanned images.
The latest version has 12 holes per layer with four layers possible in an 80mm high tube. This allows for 48 mouse tibias to be scanned per session. In the Mouse Bone Genetics project, Dena Lang is using the scanner to record mid-shaft tibia bone density properties prior to testing the tibia strength on the MTS System.
The non-destructive nature of the µCT allows for the histological properties to be determined without disturbing the sample. Prior methodologies required that the bones be imbedded in plastic, and then slices had to be cut from the plastic blocks to be examined under a microscope. This labor intensive process involved flammable and explosive chemicals, shop tools for rough cutting and precision diamond wire saws for cutting slices. The µCT scanner has reduced research time and risk of injury while increasing the reliability of results.