Neuroimaging plays a crucial role in the diagnosis, differential diagnosis, and understanding of underlying pathology in corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP). Both structural and functional imaging modalities provide valuable information for distinguishing these disorders from each other and from other neurodegenerative parkinsonian disorders. [@review2025]
Asian Population Considerations
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Overview
Mermaid diagram (expand to render)
Neuroimaging plays a crucial role in the diagnosis, differential diagnosis, and understanding of underlying pathology in corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP). Both structural and functional imaging modalities provide valuable information for distinguishing these disorders from each other and from other neurodegenerative parkinsonian disorders. [@review2025]
Asian Population Considerations
CBS and PSP imaging patterns have been studied in Japanese, Korean, and Chinese populations, revealing population-specific nuances:
Brain volume differences: Asian populations show smaller average brain volumes, affecting volumetric cutoffs
Atrophy patterns: Consistent with Western populations but with adjusted regional thresholds
FDG-PET hypometabolism: Similar patterns observed across Asian cohorts
Midbrain to pons ratio: May differ due to population-specific brain size variations
DTI metrics: Comparable sensitivity and specificity in Asian populations
Diagnostic cutoffs: Studies from J-ADNI, Korean, and Chinese cohorts provide validated cutoffs
The imaging biomarkers show generalizable utility across populations, though population-specific normative databases improve diagnostic accuracy.
Structural MRI Findings
Cortical Atrophy Patterns
CBS-Specific Atrophy
Asymmetric cortical atrophy: Contralateral to more affected side
Structural MRI remains the first-line, most cost-effective imaging modality for CBS/PSP
FDG-PET offers highest diagnostic value per cost for differential diagnosis
Amyloid PET essential for identifying AD co-pathology in CBS patients (~40-50% of cases)
Tau PET provides direct tau pathology visualization but at highest cost
Combined multimodal approach maximizes diagnostic accuracy while optimizing costs
Clinical Implementation Recommendations
| Scenario | Recommended Imaging Sequence | |----------|-------------------------| | Initial evaluation | Structural MRI → FDG-PET (if needed) | | AD co-pathology suspected | Add Amyloid PET | | Research/clinical trials | Full multimodal including Tau PET | | Resource-limited setting | MRI + clinical assessment |
Regulatory Status
FDA Clearance Status
| Modality | Status | Notes | |----------|--------|-------| | Structural MRI | FDA Cleared | Standard of care | | FDG-PET | FDA Cleared | For dementia differential | | Amyloid PET (PiB, Florbetapir, Florbetaben) | FDA Cleared | For amyloid detection | | Tau PET (Flortaucipir) | FDA Cleared | For tau imaging | | DaT-SPECT | FDA Cleared | For dopaminergic imaging |
CE Marking (Europe)
All major PET tracers (FDG, amyloid, tau) have CE marking under EU IVDR
DTI and advanced MRI sequences are CE marked on most scanners
Commercial software packages for automated analysis received CE marking
Asian Regulatory Status
| Region | Modality | Status | |--------|---------|--------| | Japan (PMDA) | FDG-PET, Amyloid PET, Tau PET | Approved | | China (NMPA) | FDG-PET, Amyloid PET | Approved | | South Korea (KFDA) | FDG-PET, Amyloid PET, Tau PET | Approved |