Combined PET-FDG and USPIO-enhanced MR imaging in patients with symptomatic moderate carotid artery stenosis
T Y Tang1, R R Moustafa, S P Howarth
1Cambridge Vascular Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK. tt279@cam.ac.uk
Introduction:
PET-FDG and USPIO-enhanced MRI are increasingly being used in depicting carotid atheroma inflammation--a risk factor for the high risk plaque. Their combined use has not been previously reported.
Report:
Two patients presenting with stroke and identified with 50% carotid stenosis on duplex ultrasonography, underwent PET FDG and USPIO-enhanced MR imaging. Results were concordant and complementary suggesting that both techniques reflect similar metabolic processes.
Discussion:
The selection of patients for carotid revascularisation has largely been based on the severity of luminal stenosis alone. The two imaging modalities, which identify inflammatory activity, may be potential surrogate risk markers in the selection of patients eligible for carotid surgery, if plaque inflammation can be correlated with risk of developing clinical symptoms.
Insights
Positron emission tomography with FDG (18F) and USPIO-enhanced MRI can identify carotid plaque inflammation. Combined use may aid in selecting patients for carotid revascularization surgery.
Area of Science:
- Cardiovascular Imaging
- Neurology
- Radiology
Background:
- Carotid atheroma inflammation is a key risk factor for high-risk plaques.
- Positron emission tomography with 18F-fluorodeoxyglucose (PET-FDG) and ultrasmall superparamagnetic iron oxide nanoparticle-enhanced magnetic resonance imaging (USPIO-enhanced MRI) are emerging techniques for assessing this inflammation.
- The combined application of these imaging modalities has not been previously investigated.
Observation:
- Two patients with stroke and 50% carotid stenosis underwent both PET-FDG and USPIO-enhanced MRI.
- The imaging results from both techniques were concordant.
- The findings suggest that both PET-FDG and USPIO-enhanced MRI reflect similar metabolic processes within the carotid plaque.
Findings:
- The study demonstrated concordant and complementary results between PET-FDG and USPIO-enhanced MRI in assessing carotid atheroma inflammation.
- Both imaging modalities appear to reflect similar underlying metabolic processes in the plaque.
Implications:
- Current patient selection for carotid revascularization primarily relies on stenosis severity.
- PET-FDG and USPIO-enhanced MRI, by identifying inflammatory activity, could serve as potential surrogate risk markers.
- Further research correlating plaque inflammation with clinical symptom development is needed to establish their role in patient selection for carotid surgery.
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