Spatial-frequency dual-constrained Mamba diffusion model for cross-modal generation from CFP to FFA

Qing Liu1, Hongqing Zhu1, Tianwei Qian2

  • 1School of Information Science and Engineering, East China University of Science and Technology, Shanghai, 200237, China.

Medical Image Analysis
|January 6, 2026
PubMed

Insights

This study introduces a new AI model, SFDC-MambaDiff, to create non-invasive retinal images from standard eye photos. This innovation offers a safer alternative to traditional dye-based angiography for diagnosing eye conditions.

Area of Science:

  • Ophthalmology
  • Medical Imaging
  • Artificial Intelligence

Background:

  • Fundus Fluorescein Angiography (FFA) is vital for diagnosing retinal diseases but carries risks associated with intravenous dye injections.
  • Adverse reactions to fluorescein dye, including allergies and severe complications, necessitate safer diagnostic alternatives.

Purpose of the Study:

  • To develop a novel AI model, Spatial-Frequency Dual-Constraint Mamba Diffusion Model (SFDC-MambaDiff), for generating non-invasive FFA images from Color Fundus Photography (CFP).
  • To provide a safe and cost-effective method for retinal screening and diagnostic support, mitigating the risks of traditional FFA.

Main Methods:

  • A Learnable Wavelet Frequency-domain Extractor (LWFE) with spiral Mamba scanning captures frequency-domain vascular features as structural priors.
  • A Dual-pyramid Spatial-domain Feature Extractor (DSFE) uses convolutions and bidirectional scanning for spatial representations as lesion-aware priors.
  • Integration of these priors via a Dual-domain Conditional Constraint Mamba module (DCCM) with dual attention guides the diffusion model's denoising process.

Main Results:

  • SFDC-MambaDiff successfully synthesizes high-fidelity, non-invasive FFA images from CFP.
  • The model demonstrates strong performance on both public and private datasets, validating its efficacy.
  • Generated images maintain crucial diagnostic information without requiring invasive dye injection.

Conclusions:

  • SFDC-MambaDiff presents a promising, non-invasive alternative to conventional FFA for retinal imaging.
  • This AI-driven approach enhances patient safety and offers potential for widespread, low-cost diagnostic applications in ophthalmology.
  • The developed model paves the way for safer, more accessible retinal disease screening.