Abstract 18663: Detection of Bacterial Device Infection of Cardiac Devices in a Rodent Model Using a Novel Pet Imaging Probe
Background: Implantable cardiac devices improve prognosis and quality of life in cardiac patients, but there are problems that stem from device infection. There is often difficulty in making a definitive diagnosis of device infections. To this end, we have developed a new approach to specifically detect bacteria using a novel PET imaging probe. Maltohexaose is taken up by bacteria via the maltodextrin transport pathway and is internalized as a major source of glucose. Mammalian tissues do not possess this transporter. In this study, we evaluated whether maltohexaose labeled with fluorine-18 (F-18 FMH) is useful as a PET tracer to detect bacterial device infection in a rat model.
Methods and results: We implanted surgical grade stainless steel device mock-ups in Sprague-Dawley rats. Methicillin sensitive Staphylococcus aureus (MSSA) in exponential growth phase was diluted to 1 X 106 CFU/ml. In the device infection group, rats were injected with 0.1ml (1 X 105 CFU) of MSSA around the mock-ups on post-operative day four. Two days later, rats were injected with F-18 FMH and were scanned with micro PET/CT. Infected devices showed a very avid uptake of tracer compared to the control (not infected) devices. The ratio of the signal in the region of interest (ROI) around the mock-up area and normal skin area was measured. The ratio of ROI in the device infection group was significantly increased compared to that in the control group that had the device but no injected bacteria. (2.34 ± 0.09 vs 1.79 ± 0.06, respectively. P<0.05, each n=4) In micro PET/CT imaging with the conventional tracer, fluorine-18-fluorodeoxyglucose, there was no significant change in the ratio of ROI between in the device infection group and in the control group. (2.21±0.12 vs 2.03±0.21, respectively. Each n=4)
Conclusion: F-18 FMH shows great promise to be a potential tracer in PET imaging for the specific diagnosis of bacterial infections of implanted cardiovascular devices.
- © 2013 by American Heart Association, Inc.