Single Photon Emission Computed Tomography / X-ray Computed Tomography (SPECT/CT) is a combined platform that allows near-simultaneous imaging of a radioactive tracer (via SPECT), and distribution of anatomy (via CT). SPECT/CT has applications in both research and clinical arenas. BIRC scientists are using it to monitor stem cell therapy, follow cell migration, and investigate new ways of imaging the heart. In clinical practice it is applied to cardiology, oncology and neurology.

This group has demonstrated that SPECT, in a canine model, can simultaneously and quantitatively monitor transplanted cell location, cell function, and perfusion to underlying tissue for 24 hours continuously. They radiolabeled and transfected stem cells with a reporter gene and transplanted them into diseased tissue. Subsequently, a reporter probe was injected and imaged with SPECT.

Using the reporter gene/reporter probe paradigm for in vivo radiolabeling is powerful for tracking cells, yet quantification is problematic due to poor contrast-to-noise arising from extensive non-specific uptake. The in vitro/in vivo dual-label strategy provides a priori localization information, improving quantification of the in vivo radiolabel.

Presently, the group is focusing on improving the value of the CT data in cardiac SPECT/CT. Most notably, they demonstrated that contrast-enhanced CT can delineate the zone of infarction, which can guide surgical delivery of stem cells, and help understand the migratory patterns post- transplantation. Currently, they are establishing partnerships with major manufacturers of imaging equipment to translate our techniques to the clinic.

Robert Stodilka, PhD, Hybrid Imaging
Frank Prato, PhD, Nuclear Medicine Physics
Gerald Wisenberg, MD, Cardiology