WI Researchers Study
Cutting-edge research using CT Scan imaging of rare samples
Bristlecone Pine logs was conducted by Forest and Wildlife
professor R Bruce Allison August 12.
Dr. Allison, whose research interest in nondestructive
testing of living
tree wood lead him to the Bristlecone Pine National Forest in
Sierra region of California in July, returned with two large log
of a tree that came down last summer as a result of a fire at
Grove visitor center. This specimen came from the same grove in
world's oldest living tree began growing over 4800 years ago!
Dendrochronologists have been studying the Bristlecone Pine
for decades to
uncover the records of weather patterns and climate change
stored in the
annual rings. Increment borers are drilled into the tree
allowing a core
sample to be extracted showing a record of ring variations.
Allison has set
as his objective the development of a nondestructive sampling of
internal structure replacing increment borers with portable
tomography scanning similar to those used in medical imaging.
is to create the portability to carry the imaging to the living
has assembled a cooperative cross-disciplinary team including
VanLysel, Associate Professor of Medicine and Medical Physics at
University of Wisconsin and Dr. Xiping Wang, wood engineer at
the US Forest
Products Laboratory plus a visiting scholar from the
and Engineering University of Harbin, China, Li Li.
The first step in developing an x-ray imaging tool is
required resolution, contrast and energy use to view internal
Bristlecone Pine has the most densely packed annual rings at
inch and therefore offers the greatest challenge for imaging.
clustered around the viewing screen of the CT Scanner at the
Institute of Medical Research on this first scanning test of the
gasped in amazement as the first images of the internal wood
into view. The wood pith, annual rings, rays cells, embedded
branches, worm holes, resin ducts and other anatomical features
displayed. Data will be analyzed over the next couple of weeks
additional tests conducted. It is Allison's hope within a few
months he will
have determined the feasibility of developing such a device and