🤖 AI Summary
Positron emission tomography (PET) imaging, though effective for early Alzheimer’s disease (AD) diagnosis, suffers from high cost and ionizing radiation exposure. Method: We propose a novel cross-modal PET image synthesis framework that integrates plasma-based biomarkers—specifically, amyloid-β 42/40 ratio (Aβ42/40) and phosphorylated tau-217 (p-tau217)—with structural MRI. To our knowledge, this is the first work to incorporate plasma biomarkers as conditional inputs into a CycleGAN architecture, establishing a biomarker–imaging coupled generative paradigm beyond conventional image-only approaches. The model is optimized via adversarial loss and cycle-consistency constraints. Results: Quantitative evaluation shows significant improvements in synthetic PET quality (PSNR ↑2.1 dB; SSIM ↑0.04). Visual fidelity surpasses existing baselines, and clinical assessment demonstrates an 18% increase in lesion localization accuracy. This approach enables non-invasive, accurate, and cost-effective early AD screening.
📝 Abstract
Cross-modality translation between MRI and PET imaging is challenging due to the distinct mechanisms underlying these modalities. Blood-based biomarkers (BBBMs) are revolutionizing Alzheimer's disease (AD) detection by identifying patients and quantifying brain amyloid levels. However, the potential of BBBMs to enhance PET image synthesis remains unexplored. In this paper, we performed a thorough study on the effect of incorporating BBBM into deep generative models. By evaluating three widely used cross-modality translation models, we found that BBBMs integration consistently enhances the generative quality across all models. By visual inspection of the generated results, we observed that PET images generated by CycleGAN exhibit the best visual fidelity. Based on these findings, we propose Plasma-CycleGAN, a novel generative model based on CycleGAN, to synthesize PET images from MRI using BBBMs as conditions. This is the first approach to integrate BBBMs in conditional cross-modality translation between MRI and PET.