Temporal evolution of ischemic lesions in nonhuman primates: a diffusion and perfusion MRI study

Area of Science:

• Neuroscience
• Radiology
• Medical Imaging

Background:

• Stroke is a leading cause of death and disability worldwide.
• Understanding the spatiotemporal evolution of stroke lesions is crucial for developing effective treatments.

Purpose of the Study:

• To examine the evolution of ischemic stroke lesions in nonhuman primates using advanced MRI techniques.
• To characterize the spatiotemporal dynamics of infarct growth in the acute phase of stroke.

Main Methods:

• Permanent middle cerebral artery (MCA) occlusion was induced in adult rhesus monkeys.
• High-resolution diffusion-weighted imaging (DWI) and perfusion MRI were performed at multiple time points post-occlusion.
• Lesion volumes were quantified and validated with T2-weighted imaging (T2W) and H&E staining.

Main Results:

• Stroke infarcts exhibited a natural logarithmic growth pattern in the hyperacute phase (1-6 hours).
• Infarct volumes increased significantly from 6 to 96 hours post-occlusion.
• Diffusion-perfusion mismatch diminished by 48 hours, and logarithmic predictions correlated well with observed lesion volumes.

Conclusions:

• Infarct evolution follows a natural logarithmic pattern in the early stages of ischemic stroke.
• This logarithmic model can predict infarct volume growth in the acute phase.
• The nonhuman primate model and MRI protocols offer a robust platform for stroke research and therapeutic development.