Related Experiment Video
Updated: May 16, 2026
Synthesis, Characterization, and Application of Superparamagnetic Iron Oxide Nanoprobes for Extrapulmonary Tuberculosis Detection
Published on: February 16, 2020
Magnetic resonance imaging of soft tissue infection with iron oxide labeled granulocytes in a rat model
Hassina Baraki1, Norman Zinne, Dirk Wedekind
1Department of Cardio-Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany. baraki.hassina@mh-hannover.de
Object:
We sought to detect an acute soft tissue infection in rats by magnetic resonance imaging (MRI) using granulocytes, previously labeled with superparamagnetic particles of iron oxide (SPIO).
Materials And Methods:
Parasternal infection was induced by subcutaneous inoculation of Staphylococcus aureus suspension in rats. Granulocytes isolated from isogenic donor rats were labeled with SPIO. Infected rats were imaged by MRI before, 6 and 12 hours after intravenous injection of SPIO-labeled or unlabeled granulocytes. MR findings were correlated with histological analysis by Prussian blue staining and with re-isolated SPIO-labeled granulocytes from the infectious area by magnetic cell separation.
Results:
Susceptibility effects were present in infected sites on post-contrast T2*-weighted MR images in all animals of the experimental group. Regions of decreased signal intensity (SI) in MRI were detected at 6 hours after granulocyte administration and were more pronounced at 12 hours. SPIO-labeled granulocytes were identified by Prussian blue staining in the infected tissue and could be successfully re-isolated from the infected area by magnetic cell separation.
Conclusion:
The application of SPIO-labeled granulocytes in MRI offers new perspectives in diagnostic specificity and sensitifity to detect early infectious processes.
Insights
Magnetic resonance imaging (MRI) using superparamagnetic iron oxide (SPIO)-labeled granulocytes can detect early soft tissue infections in rats. This method enhances diagnostic sensitivity and specificity for identifying infectious processes.
Area of Science:
- Biomedical Imaging
- Infectious Disease Diagnostics
- Nanomedicine
Background:
- Early detection of soft tissue infections is crucial for effective treatment.
- Conventional diagnostic methods may lack sensitivity for subtle infectious processes.
Purpose of the Study:
- To evaluate the efficacy of MRI with SPIO-labeled granulocytes for detecting acute soft tissue infections in a rat model.
- To assess the diagnostic potential of this novel imaging approach.
Main Methods:
- Acute soft tissue infection was induced in rats using Staphylococcus aureus.
- Granulocytes were isolated and labeled with SPIO.
- Infected rats underwent MRI before and after intravenous injection of labeled or unlabeled granulocytes.
- MR findings were correlated with histological analysis and SPIO-labeled granulocyte re-isolation.
Main Results:
- MRI revealed susceptibility effects at infected sites post-contrast.
- Decreased signal intensity in MRI was observed at 6 and 12 hours after SPIO-labeled granulocyte administration.
- SPIO-labeled granulocytes were confirmed in infected tissues and successfully re-isolated.
Conclusions:
- SPIO-labeled granulocytes enhance MRI for detecting early infectious processes.
- This technique offers improved diagnostic specificity and sensitivity.
- It presents a promising new perspective for early infection diagnosis.
