Related Experiment Video
Updated: Jan 10, 2026
Non-invasive Imaging of Acute Allograft Rejection after Rat Renal Transplantation Using 18F-FDG PET
Published on: April 28, 2013
[18F]Fluorodeoxyglucose Positron Emission Tomography for Diagnosis and Monitoring of Acute Staphylococcus aureus
Emma Faddy1,2,3, Mikkel Illemann Johansen2, Christoffer Gadeberg1,2
1Department of Clinical Medicine, Infectious Diseases, Aarhus University, Aarhus N, Denmark.
Objectives:
Vascular graft or endograft infections (VGEIs) pose a detrimental complication when using vascular grafts and are challenging to diagnose and treat. This study examined the progression of infection and the antimicrobial response in VGEI using [18F]Fluorodeoxyglucose (chemical name, 2-Deoxy-2-[18F]fluoroglucose) (FDG) positron emission tomography (PET), ex vivo bacterial quantification, and histology in a VGEI rat model.
Methods:
In this experimental study, 97 male Sprague-Dawley rats had a polytetrafluorethylene graft surgically implanted in the carotid artery. The graft was either preinoculated with Staphylococcus aureus, S. epidermidis, or saline. Up to 31 days after surgery, rats were FDG-PET-scanned. Subsequently, they were killed, and the implants were retrieved for analysis. A subgroup of infected rats received daptomycin and rifampicin from days 20 to 29.
Results:
Tracer uptake around the implant, measured by maximum standardized uptake value (SUVmax), declined over time in all groups. Between groups, SUVmax was highest in untreated S. aureus-infected rats. When comparing antibiotic-treated and uninfected rats by day 31, there was no difference in SUVmax, although the treated rats were still infected. Histology revealed widespread inflammation by day 10 in S. aureus-infected rats, which decreased by days 20 and 31 with encapsulation of the infection, alongside increased plasma interleukin-10.
Conclusions:
FDG-PET differentiated untreated S. aureus-infected rats from uninfected ones but failed to monitor infection progression, as SUVmax declined over time despite a constant bacterial load. FDG-PET could not distinguish between uninfected rats and those with suppressed infection, likely due to reduced inflammation and encapsulation of the infection.
Insights
[18F]Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) showed promise in identifying vascular graft infections but could not track infection progression or differentiate suppressed infections in a rat model.
Area of Science:
- Biomedical imaging
- Infectious disease research
- Surgical complications
Background:
- Vascular graft or endograft infections (VGEI) are serious complications.
- Diagnosing and treating VGEI is challenging.
- Novel imaging techniques are needed to monitor infection and treatment response.
Purpose of the Study:
- To evaluate the utility of [18F]Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) in assessing VGEI.
- To examine infection progression and antimicrobial response in a VGEI rat model.
- To correlate imaging findings with ex vivo bacterial load and histology.
Main Methods:
- A VGEI rat model was established using polytetrafluorethylene grafts inoculated with Staphylococcus aureus or Staphylococcus epidermidis.
- Rats underwent serial FDG-PET scans up to 31 days post-surgery.
- A subgroup of infected rats received daptomycin and rifampicin; implants were analyzed post-euthanasia.
Main Results:
- FDG-PET showed higher tracer uptake (SUVmax) in untreated S. aureus-infected rats compared to other groups.
- SUVmax declined over time in all groups, even with persistent bacterial load.
- Histology indicated inflammation decreased with infection encapsulation in treated rats, despite similar SUVmax to uninfected controls.
Conclusions:
- FDG-PET can differentiate untreated S. aureus VGEI from uninfected states.
- FDG-PET's declining SUVmax limits its ability to monitor infection progression or treatment efficacy.
- Reduced inflammation and encapsulation may explain FDG-PET's inability to distinguish suppressed infections from uninfected states.
More Related Videos
09:36Modified Heterotopic Hindlimb Osteomyocutaneous Flap Model in the Rat for Translational Vascularized Composite Allotransplantation Research
Published on: April 26, 2019
07:46Experimental Endocarditis Model of Methicillin Resistant Staphylococcus aureus MRSA in Rat
Published on: June 4, 2012