SPECT/MRI Hybrid Prototype Looks Deep into Soft Tissues of the Brain

Research points to the possibility of a new hybrid molecular imaging system that uses single photon emission tomography (SPECT) and magnetic resonance technology (MR). The new technology could provide a greater depth of data about a host of biologic processes and anatomic information including soft-tissue contrast, which is important for many diagnoses.

"By combining SPECT and MR imaging in a single scan, researchers can acquire fused images that provide meaningful information for brain studies, heart imaging and a range of other applications,” said Benjamin M. W. Tsui, Ph.D., lead researcher and professor of radiology at Johns Hopkins University (Baltimore, MD, USA). "Imaging the human brain using this technique could revolutionize diagnostic radiology and improve patient care.”

Earlier research has been conducted for the development of other hybrid molecular imaging systems that combine positron emission tomography (PET) and MR, but this is the first study evaluating the feasibility of a SPECT/MR system. The introduction of MR to SPECT imaging not only adds useful anatomic and biochemic information, but it would also help to compensate for other image-degrading factors, such as photon attenuation and scatter, which can be present in SPECT imaging.

The researchers developed a fully MR-compatible, stationary ring-type SPECT prototype using cadmium zinc telluride (CZT) solid-state detector modules. All components used for the new preclinical SPECT system were entirely composed of nonferrous materials to avoid image artifacts that could otherwise occur within the magnetic field. In this study, researchers did not have to rotate the SPECT component, but the imaging scanner was able to capture dynamic data using multiple projection views. The team also investigated image reconstruction methods that would best work with data acquired from the new imaging system. This study, according to the researchers, proves that SPECT/MR is a viable technology that could enhance the diagnostic capability of SPECT alone and provide additional information that SPECT/CT cannot. Plans to extend the preclinical prototype to clinical brain SPECT/MR are underway and clinical trials are expected to begin within three or four years.

Dr. Tsui's research group for this study was part of a collaboration that included the University of California, Irvine, and was led by Gamma Medica-Ideas (Northridge, CA, USA) under the support of a U.S. National Institutes of Health (NIH) SBIR research grant.

The study's findings were presented at the Society of Nuclear Medicine's (SNM) 57th annual meeting, June 5-9, 2010, in Salt Lake City, UT, USA.

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