Diffusion and perfusion MR patterns of central nervous system lymphomas.

Area of Science:

• Radiology
• Oncology
• Neuroscience

Background:

• Central nervous system lymphomas (CNSLs) are rare tumors with variable standard MRI appearances.
• Tumor origin (primary/secondary) and patient immune status influence CNSL presentation.

Purpose of the Study:

• To analyze imaging patterns of CNSLs using diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI).
• To differentiate CNSL subtypes and patient immune statuses based on advanced MRI techniques.

Main Methods:

• 16 CNSLs (14 primary, 2 secondary, 13 immunocompetent, 3 immunodeficient) underwent MRI with DWI and T2* dynamic susceptibility contrast (DSC) perfusion.
• Analysis included apparent diffusion coefficient (ADC) and perfusion parameters (rCBV, rPH, rPSR) in mean and maximal tumor regions.

Main Results:

• All CNSLs demonstrated restricted diffusion (low ADC) and hypoperfusion (low rCBV, rPH; high rPSR).
• No significant differences in ADC or perfusion parameters were found between primary/secondary CNSLs or immunocompetent/immunodeficient patients.
• Perfusion without preload showed significantly higher rCBV and rPH, and lower rPSR.

Conclusions:

• CNSLs consistently display restricted diffusion and hypoperfusion, regardless of origin or immune status.
• Dynamic susceptibility contrast perfusion without preload is recommended for CNSL characterization.