Dual-Stream Contrastive Latent Learning GAN for Brain Image Synthesis and Tumor Classification

Generative Adversarial Networks (GANs) prioritize pixel-level attributes over capturing the entire image distribution which is critical in image synthesis. To address this challenge, we propose (DSCLPGAN) a dual-stream generator coupled with contrastive latent projection (CLP) for the robust augmentation of MRI images. The dual- stream generator in our architecture incorporates two specialized processing pathways: one dedicated to local feature variation modeling, while the other captures global structural transformations, ensuring a more comprehensive synthesis of medical images. We used a transformer-based encoder-decoder framework for contextual coherence and the contrastive learning projection (CLP) module integrates contrastive loss into the latent space for generating diverse image samples. The generated images undergo adversarial refinement using an ensemble of specialized discriminators where discriminator 1 (D1) ensures classification consistency with real MRI images, discriminator 2 (D2) produces a probability map of localized variations and discriminator (D3) functions for preserving structural consistency. For validation, we utilize a publicly available MRI dataset which contains from 3064 T1-weighted contrast- enhanced images with three types of brain tumor: meningioma (708 slices), glioma (1426 slices), and pituitary tumor (930 slices). Experimental results demonstrate state-of-the-art performance, achieving an SSIM of 0.99, classification accuracy of 99.4% for an at an augmentation diversity level of 5 and PSNR of 34. 6 dB. Our approach has the potential of generating high-fidelity augmentations for reliable AI-driven clinical decision support systems.