Features: Feb. 4, 2002
Terahertz Imaging Provides Advantages
Terahertz-computed tomography (T-ray CT)
is a new imaging process that extends beyond X-ray CT methods
and has enabled Rensselaer researchers to create 3-D images
of dielectric targets, including biological objects, such
as cross sections of bones.
3-D image of turkey bone created through
Terahertz imaging is attractive for a number
of reasons: the radiation is non-ionizing and poses very
few safety risks, it is capable of sub-millimeter resolution,
and it provides spectroscopic information.
In biomedical application, T-ray CT could
lead to enhanced imaging and diagnostic techniques for skin
cancer, skin burn severity, and even tooth cavities. In
industrial application, T-ray CT could be a mailroom's "eyes"
in determining if there are spores in a letter, for example.
The inspiration for T-ray CT was drawn from
the now ubiquitous X-ray CT method. However, terahertz CT
can "see" a different spectrum range than X-ray
CT, according to Xi Cheng Zhang, the J. Erik Jonsson Distinguished
Professor of Science.
The technique is made possible by an earlier
discovery in using a "chirped probe" that delivers
picosecond-long "blasts" or "chirped pulses"
of light that can accelerate the time it takes to acquire
accurate images, especially in biological tissue, from hours
or days, down to minutes or seconds.
"Terahertz gap is a scientifically
rich but technologically unexplored frequency band,"
says Zhang "This terahertz frequency range presents
the next frontier in imaging science and technology."