High resolution extremity CT for biomechanics modeling Page: 4 of 5
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
3. RESULTS:
Contrast sensitivity on the CT images clearly resolves soft tissue from bone and cartilage,
as well as fine structural detail in the trabecular bone. The skin/parafin interface is clearly
resolved.
4. DISCUSSION:
The CI scans of the extremity that were obtained have more than met the expectations of
the finite element analysts in providing a data set of appropriate detail for defining articular
surface geometries and bone internal structural detail. The use of a fresh-frozen, thawed
extremity provides minimal distortion from in vivo anatomy; the anatomy is far closer to in
vivo than a fixed specimen would be, with the shrinkage in ligaments and cartilage that
results from processing.
Parafn proved to be a less than ideal support material because of the diifficulty in managing
hot parafin, and the propensity to form air voids when cooling. Fortunately, the voids do
not directly impinge on the extremity, so do not degrade any of the surface geometries.
5. CONCLUSIONS:
Industrial CT systems can provide a level of detail for anatomical structure that is not
available from medical CIT scanners because of constraints to limit radiation to living tissue.
When scanning time and radiation dose are not determining factors, much higher quality
images can be produced. Thus, a new research tool is provided by scanning archival
cadaveric material with industrial CT.
Future plans in CT development are to characterize our system with regard to x-ray and
light scatter. Also, it is planned to reduce x-ray scatter effects by employing a low density
foam support material in place of parafin in the container and by using suitable pre-
collimation and filtering. It is also planned to perform the reconstruction with a cone beam
algorithml3.
Near future plans also include scanning lower extremities and spine segments.
6. REFERENCES:
1. Bradley N. Maker, originators: J.O. Hollquist, Robert M. Ferencz, NIKE3D: A
Nonlinear Implicit 3-Dimensional Finite Element Code for Solid and Structural Mechanics,
User's Manual, UCRL: MA105268, Jan., 1991.
2. Robert G. Whirley, Bruce E. Engelmann, J. O. Hallquist, DYNA3D: A Nonlinear
Explicit 3-Dimensional Finite Element Code for Solid and Structural Mechanics, User's
Manual, UCRL: MA107254 , Rev. 1, Nov., 1993.
3. Viewpoint Datalabs, 870 West Center, Ovem, UT 84057.
4. C. M. Logan, J. M. Hernandez, G. J. Devine, "Quantitative Radiography",
Proceedings of the 1991 Spring Conference of the American Society for Nondestructive
Testing, A manuscript containing four related papers from this conference is available as
LLNL Report UCRL-ID-106201(1991).
5. "Nondestructive Evaluation," Harry E. Martz, Lawrence Livermore National
Laboratory, Livermore, Calif., UCRL-53868-94; Lawrence Livermore National
Laboratory, Livermore, Calif., UCRL-ID-119059, February 1995.
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Ashby, A. Elaine; Brand, Hal; Hollerbach, Karin; Logan, Clint M. & Martz, H. E. High resolution extremity CT for biomechanics modeling, article, September 23, 1995; California. (https://digital.library.unt.edu/ark:/67531/metadc623653/m1/4/: accessed April 19, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.