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.

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