Quantitative MRI Measures in SIV-Infected Macaque Brains

Area of Science:

• Neuroimaging
• Primate Models
• Infectious Diseases

Background:

• Human Immunodeficiency Virus (HIV) infection causes central nervous system (CNS) damage, affecting structural, functional, and neurochemical integrity.
• Simian Immunodeficiency Virus (SIV) in macaques serves as a crucial animal model for studying HIV-associated neuropathology and cognitive impairment.
• Low-field MRI (≤1.5T) provides inadequate resolution for small non-human primate (NHP) brains, limiting its utility in neuroAIDS research.

Purpose of the Study:

• To review advanced Magnetic Resonance Imaging (MRI) techniques applicable to macaque models of neuroAIDS.
• To discuss the relationship between quantitative MRI measures and peripheral T-cell changes in SIV-infected macaques.
• To highlight the benefits of high-field MRI (≥3T) for studying neuroAIDS in NHPs.

Main Methods:

• Review of multiple high-field MRI modalities including Diffusion Tensor Imaging (DTI), perfusion MRI, MR Spectroscopy (MRS), volumetric MRI, contrast-enhanced MRI, and functional MRI.
• Application of these MRI techniques in SIV-infected macaque models.
• Correlation analysis between quantitative MRI metrics and blood T-cell counts.

Main Results:

• High-field MRI demonstrates significant structural and functional brain abnormalities in SIV-infected macaques, mirroring human neuroAIDS.
• Quantitative MRI measures show correlations with T-cell alterations, indicating potential biomarkers for disease progression.
• Advanced MRI techniques provide detailed insights into neuroinflammation, neurodegeneration, and viral activity within the CNS.

Conclusions:

• High-field MRI is essential for detailed characterization of CNS pathology in NHP models of neuroAIDS.
• MRI findings in SIV models offer valuable insights into HIV neuropathogenesis and potential therapeutic targets.
• Quantitative MRI measures may serve as non-invasive biomarkers for monitoring disease progression and treatment response in neuroAIDS.