Molecular imaging revolutionised by Dynamic SPECT breakthrough
7 December 2005
Details of a new medical imaging device that increases the speed of
molecular imaging more than 10-fold was revealed at the annual meeting of
the Radiological Society of North America last week. It gives the promise of
revolutionizing the fields of cardiac and oncology imaging.
The new technology, Dynamic SPECT (D-SPECT), employs a compact camera
with a bank of detector/collimator columns. Tungsten collimators are
employed in front of multiple small cadmium zinc telluride crystals. Each
detector column turns independently, allowing the object of interest to be
viewed from hundreds to thousands of different viewing angles, according to
lead author Daniel S. Berman, M.D., professor of medicine at University of
California, Los Angeles (UCLA). This strategy also enables imaging photons
and localizing them in an entirely new way.
"In evaluating heart disease, this breakthrough in technology could
unlock the door to much faster and more accurate cardiac stress imaging and
better identification of patients at risk," said Dr. Berman.
There has been no fundamental change in single photon imaging systems
since the electrical engineer, Hal O. Anger, invented the nuclear camera
instrumentation that has been used for the past 50 years.
"The Anger camera has been one of the most enduring and innovative
designs in the history of medical imaging," said Jack A. Ziffer, Ph.D.,
M.D., chairman of the Radiology Department at Baptist Hospital of Miami.
"The revolutionary design of the D-SPECT system may change the way we image
molecular processes in the body, having ramifications for CT as well."
Phantom studies were carried out to assess sensitivity and resolution of
D-SPECT in comparison with the conventional Anger Camera SPECT (A-SPECT). In
all studies, the D-SPECT system sensitivity was more than 10 times greater
than A-SPECT. D-SPECT spatial resolution was two times higher than A-SPECT,
despite imaging for one-tenth the time. Excellent images in human volunteers
have also been obtained in two minutes with D-SPECT compared to 17 minutes
with conventional SPECT, according to Dr. Berman.
In the nuclear environment, this innovative way of imaging photons and
determining their source provides sensitivity gains of at least 10-fold.
That would enable decreasing radiation dose 10-fold, or imaging 10 times
faster. Because of that, entirely new tracers can be developed, promising to
revolutionize the fields of cardiac and oncological imaging, according to
Dr. Ziffer. In conjunction with CT, this fast new SPECT approach could lead
to the routine use of smart contrast agents, taking the guess work out of CT
interpretation, added Dr Ziffer.