Investigators secure new SPECT scanner

By Kristen Holland Shear / Week of Jan. 8-14, 2011

UT Southwestern investigators studying animal models relevant to cancer, autoimmune diseases, metabolic disorders and many other conditions have a new research tool at their disposal – a single photon emission computed tomography (SPECT) scanner.

The medical center recently received nearly $900,000 from the National Institutes of Health to purchase the scanner. Dr. Orhan Oz, associate professor of radiology and principal investigator on the grant, said the funds were part of the American Recovery and Reinvestment Act, the $787 billion stimulus package President Obama signed into law in February 2009.

“The success of our application reflects the high quality of basic and translational science at this institution,” said Dr. Oz, who prepared the grant application with Dr. Jon Anderson, professor of radiology, and Dr. Xiankai Sun, assistant professor of radiology.

SPECT is a radioisotope-based imaging technique that uses gamma-ray emitting atoms called radionuclides, which are incorporated into molecules that target specific organs, diseases or physiological processes. The scanner detects these gamma-rays, then uses mathematical processes to reconstruct a 3-D image of both the location and the amount of trace material injected into a research subject. Tracers are substances generally injected into animals to measure the activity or speed of physiological processes as well as to track the movement of a substance through a specific tissue or the body. Radioactive forms of technetium, indium, iodine, gallium and thallium commonly are used to make tracers for SPECT imaging in medical research.

Although radiology researchers at UT Southwestern have designed custom SPECT scanners for small-animal imaging before, Dr. Oz said that the new machine will enable researchers to obtain very high-resolution images of organs and determine disease mechanisms, severity, progression and regression in mouse, rat and rabbit models at high-throughput rates not previously possible.

“For the first time, we’ll be able to image two or even three processes simultaneously in living animals,” Dr. Oz said. “It also enables us to monitor infections and organ function after genetic or therapeutic manipulation and to track stem cells.

“For example, we can obtain very high-resolution images of the thyroid, brain and kidney based on tracers that target either blood flow to the organs or the expression of a specific receptor within these organs.”

The new scanner also presents additional educational opportunities for radiology residents and graduate students. “We are working with the manufacturer to give our faculty access to raw data for use in research on image reconstruction algorithms and other areas of interest,” Dr. Oz said.