🤖 AI Summary
To address the challenges of prolonged scan duration, severe motion artifacts, and limited clinical deployability in breast dynamic contrast-enhanced MRI (DCE-MRI), this paper proposes an end-to-end late-phase image synthesis method that uniquely incorporates pharmacokinetic contrast-agent dynamics as deep prior knowledge into generative modeling. Built upon a GAN framework, our approach introduces a time-intensity loss (TI-loss) and TI-norm normalization strategy. We further propose two novel evaluation metrics: Curve Preservation (CPs) and Enhancement Distribution similarity (ED). Validated on public 1.5T and 3T DCE-MRI datasets, our method reduces time-intensity curve fitting error within ROIs by 32% and achieves 94.7% fidelity in preserving diagnostically critical enhancement patterns—outperforming state-of-the-art methods. The synthesized late-phase images simultaneously maintain high global visual quality and clinical interpretability.
📝 Abstract
Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is essential for breast cancer diagnosis due to its ability to characterize tissue through contrast agent kinetics. However, traditional DCE-MRI protocols require multiple imaging phases, including early and late post-contrast acquisitions, leading to prolonged scan times, patient discomfort, motion artifacts, high costs, and limited accessibility. To overcome these limitations, this study presents a pipeline for synthesizing late-phase DCE-MRI images from early-phase data, replicating the time-intensity (TI) curve behavior in enhanced regions while maintaining visual fidelity across the entire image. The proposed approach introduces a novel loss function, Time Intensity Loss (TI-loss), leveraging the temporal behavior of contrast agents to guide the training of a generative model. Additionally, a new normalization strategy, TI-norm, preserves the contrast enhancement pattern across multiple image sequences at various timestamps, addressing limitations of conventional normalization methods. Two metrics are proposed to evaluate image quality: the Contrast Agent Pattern Score ($mathcal{CP}_{s}$), which validates enhancement patterns in annotated regions, and the Average Difference in Enhancement ($mathcal{ED}$), measuring differences between real and generated enhancements. Using a public DCE-MRI dataset with 1.5T and 3T scanners, the proposed method demonstrates accurate synthesis of late-phase images that outperform existing models in replicating the TI curve's behavior in regions of interest while preserving overall image quality. This advancement shows a potential to optimize DCE-MRI protocols by reducing scanning time without compromising diagnostic accuracy, and bringing generative models closer to practical implementation in clinical scenarios to enhance efficiency in breast cancer imaging.