Scanning FAQ

  • Do you take in projects from outside researchers?
    Yes! In fact, one of the primary purposes of this facility is to provide accessible and top-quality high-resolution scanning services for the geological and overall scientific community.

  • Are there any samples excluded from your scanning services?
    Yes. UTCT will not scan archaeological, anthropological or paleontological samples for clients not affiliated with an academic or government institution.

  • What are your prices?
    Scanning services cost $120/hour for academic projects, or $281/hour for commercial work. Scanning time includes not only image data acquisition, but also the time necessary to mount the specimen, and to calibrate and optimize the scanner. There are also associated charges relating to reconstructing the raw CT data into slices, processing the data to minimize artifacts, and transferring and archiving the data in perpetuity. These associated charges are billed at a lower “image processing” rate of $90/hour academic and $191/hour commercial, as above. We also offer additional image processing and analysis services at the image processing rate. We must have a Scan Agreement Form on file before we start any project. It is downloadable here.

  • Do you offer a discount to NSF researchers?
    Our status as an NSF-supported multi-user facility entitles certain NSF-funded projects to be charged at reduced rates (50% reduction for projects funded by the NSF GEO directorate, including EAR, OCE and AGS divisions), and preferred scheduling. We can also provide a limited number of free test scans (typically less than an hour of scanning) as proof-of-principle to justify or help to obtain funding for a complete study.

  • How long does it take to acquire an individual scan slice?
    Scanning times are quite variable, depending on the scientific objectives of the researcher, the geometrical and material characteristics of the objects being scanned, and the scanning system we use. On the NSI system, scan times are generally on the order of 30-60 minutes, but can range from about 20 seconds to 3 hours. On the Xradia MicroXCT scanner scan durations range from as little as 15 minutes to as much as 20 hours or longer, depending on the size and composition of the specimen and the resolution desired.In general, if the details being inspected have a large density contrast with the surrounding matrix, or if they are fairly large in proportion to the overall object, scan times are shorter; conversely, if the features being studied are small or consist of subtle density variations, longer scan times will probably be required to distinguish them with sufficient clarity. Denser objects tend to take longer to scan than less-dense objects, and very small objects often require longer scan times to achieve suitable noise reduction in the images. On our NSI system, a good, general base estimate is 60 minutes per scan, which will probably be within a factor of two of the actual scan duration. On the Xradia MicroXCT, average scan durations range from 1.5 to 4 hours. We might be able to provide a better estimate if you describe your sample and imaging requirements to us.

  • What resolution do the UT scanners have?
    Again, this depends largely on sample characteristics, of which size is the most directly influential. A useful benchmark is that the images we collect are at most 2048×2048 pixels, and the entire sample should generally fit within the scan field of view. Thus, insofar as it takes a few pixels on a computer image to distinguish a feature, our maximum resolution is correspondingly a few 2048th’s of the maximum dimension of the object in the scan plane. Both systems can generate 1024×1024-pixel images which are acquired four times faster than a 2048 scan.

  • How large/small a sample can you scan?
    Our smallest objects scanned to date have been a few tens of microns in diameter. The largest field of view we can image when scanning using our NSI system is about 40 cm. Samples scanned on the NSI system can be up to 80 cm tall; the vertical throw is partially dependent on the magnification of the scan. On the Xradia MicroXCT, samples can be up to about 10 cm in diameter and 7 cm in height.

  • How thin can you make the slices?
    This depends on the sample size and the scanning system we use to image it. For both systems, achievable slice thickness is a direct function of the object maximum dimension in the scan plane and corresponds to roughly 1/2000thof the object diameter. Thus, for an object 30 mm in diameter, slice thickness would be approximately 15 micrometers.

  • What kind of sample preparation needs to be done?
    It depends on what you’re scanning; in many cases, no preparation needs to be done at all, or whatever preparation that is necessary is best handled by us. In general, the optimal sample geometry for scanning efficiency and image quality is a cylinder. If this geometry is not possible, it would still be good to have the sample be as equidimensional as possible in the scan plane. One technique we often use is to pack the sample in a cylindrical container surrounded by material of similar density.

  • Is there any other information that you need for scanning?
    In general no, but the more information you provide the better we might be able to optimize the imaging conditions. One thing that can sometimes be helpful is compositional information, such as what materials or mineral phases are in the sample, and if possible detailed chemical compositions of them. Another useful item is often a thin section or some other means of “ground-truthing” our scanning to compare what we see in the images to what is really in the sample.

  • How much would it cost to scan my sample?
    To estimate the duration (and thus price) for a scan, start with a half-hour to hour for setup, calibration, and optimization of the scanner for the particular requirements of your project (billed at the scanning rate). A “typical” sample takes from 0.5-8 scanning hours, but of course in any specific case it can be shorter or longer. We also charge image processing time for reconstructing the raw CT data into slices and using custom software to minimize artifacts in the data (one to three hours, depending on the volume of data), and subsequently for transferring and archiving the data (in perpetuity) and making them available to you via FTP (one hour for the first Gb, 0.25 hours for each additional Gb). Hourly rates are listed above. The size of the data set can be estimated by multiplying the number of slices times the size per slice (2 Mb per slice for a 1024 X 1024 pixel reconstruction; 8 Mb per slice for a 2048 X 2048 pixel reconstruction). The easiest way to estimate the cost of scanning a sample is to ask us!

  • Can CT scanning provide direct density measurements?
    Yes, but it would take some preliminary work geared to a specific study objective. CT images generally reflect relative density variations in the object being scanned, but specific gray scale values reflect a wide range of factors determined by the scanning conditions. In order to obtain density data, calibrations must be performed based on the specific material being scanned at the exact scanning conditions that will be used.

  • What file format do you produce?
    The native format is a computer TIFF file in unsigned 16-bit gray scale (i.e., intensity values range from 0 to 65535). Exporting to an 8-bit format entails some loss of image information, but in many cases it is not very significant, and most present-day software packages for image processing or analysis (Adobe Photoshop, ImageJ) tend to work much better with 8-bit images. If necessary, for a fee we can also convert the data to other formats such as DICOM. We also archive all of the data that we acquire in perpetuity.

  • How do I get my data?
    We will make your data available for download via FTP. You will be provided with a FTP address and any required login information. A hard copy of your data can be provided for an additional fee ($90/DVD or CD for academic projects; $191/DVD or CD for commercial projects). If you require assistance using FTP, please see How to retrieve your data via FTP.

  • What image processing services do you provide?
    We principally provide services to aid in visualization of the scan data in 2D and 3D by creating images and animations. The image folio on the home page of this web site provides good examples of many of the things we can do. We are also developing capabilities for more sophisticated image analysis, such as 3D object identification and characterization and STL file creation. Our facility includes a computer lab that can be made available to outside researchers wishing to come here to work with their data.

  • I want to try something out. What should I do next?
    Two things: first, download and read the scan agreement form, as we’ll need a signed copy of it before we can scan anything. Second, contact us, either by email at maisano@jsg.utexas.edu (preferred), or by phone at (512) 471-0260.

  • What's your turnaround time?
    It varies depending on our workload at the time, so consult with us to find out what the current situation is. In general, test scans are the lowest priority, so turnaround time for them tends to be longer. If you have a special deadline by which you need scans, such as a grant application deadline, let us know and we’ll do our best to accommodate it.

  • How and where should I ship specimens, and how will specimens be handled?
    We require that either Matt Colbert or Jessie Maisano be notified before samples are shipped to us for scanning. Samples should be securely packed in a sturdy container. We will generally use the same shipping material to send the specimen back to you. The CT lab has alarm-secured storage in locked specimen cabinets. Let us know if there are any special requirements for specimen storage (e.g., whether the specimen is pickled in ethyl alcohol, isopropyl alcohol, or formalin; whether the specimen is to remain frozen, etc.).

    For all natural history samples (e.g., rocks, fossils, or biological material) we also require that you provide specimen identification and basic locality data. These data are entered into our internal database, and do not leave the lab without your consent. Such data should include, but not necessarily be limited to: taxon name (to smallest identified level) or rock type; specimen number (if accessioned into a collection); general locality information; age (in the case of rocks and fossils); and any other ancillary information that is deemed appropriate (i.e., sex, maturity, etc.). Specimen loan forms from museums will often include all this information, and these loan forms should indicate that we have permission to scan the specimen.

    In most cases we require that biological and fossil specimens either be accessioned into a recognized museum or natural history collection, or have a guarantee that they will be accessioned. Exceptions may be made, such as when there are plans to destructively examine experimental specimens after scanning.

    Let us know if there are special requirements or restrictions in preparing specimens for scanning. We will need permission to remove specimen labels from biological samples if necessary to improve scan quality. In a similar vein, fossil samples occasionally are damaged in shipping, or may benefit from preparation prior to scanning. With permission we can use the services of the professional preparators at the Vertebrate Paleontology Laboratory of the Jackson School of Geosciences.

    Most of the samples that we scan are shipped to us rather than hand-carried.

    The following address serves for all carriers:

    The University of Texas at Austin
    Department of Geological Sciences
    Either Matt Colbert or Jessie Maisano
    2275 Speedway Stop C9000
    Austin, TX 78712-1722
    (512) 471-0260