18F-FDG Brain PET/MRI in Postischemic Hyperperfusion

Area of Science:

• Neurology
• Neuroimaging
• Stroke Medicine

Background:

• A 58-year-old male with a history of myocardial infarction and ventricular thrombus presented with recurrent stroke symptoms.
• Initial symptoms included left arm weakness, followed by dysarthria and right-sided weakness, indicating cerebrovascular events.

Purpose of the Study:

• To investigate the cause of impaired memory in a stroke patient that was not explained by ischemic areas.
• To differentiate between neurodegenerative disease and other causes of cognitive impairment using advanced neuroimaging.

Main Methods:

• Structural imaging (CT/MRI) was used to identify acute/subacute ischemic stroke locations in the right frontal and parietal lobes.
• 18F-FDG brain PET/MRI was performed to evaluate for neurodegenerative disease and assess metabolic activity in brain regions.

Main Results:

• Structural imaging confirmed ischemic strokes in the right frontal and parietal lobes.
• 18F-FDG brain PET/MRI ruled out neurodegenerative disease.
• Focal hypermetabolism was observed in the acute/subacute infarct areas, consistent with luxury perfusion (postischemic hyperperfusion).

Conclusions:

• The patient's memory impairment was attributed to luxury perfusion in the infarct areas, not a primary neurodegenerative process.
• 18F-FDG brain PET/MRI is a valuable tool for differentiating post-stroke hyperperfusion from neurodegeneration in cognitive impairment workups.