Cross-modal medical image-report retrieval task plays a significant role in clinical diagnosis and various medical generative tasks. Eliminating heterogeneity between different modalities to enhance semantic consistency is the key challenge of this task. The current Vision-Language Pretraining (VLP) models, with cross-modal contrastive learning and masked reconstruction as joint training tasks, can effectively enhance the performance of cross-modal retrieval. This framework typically employs dual-stream inputs, using unmasked data for cross-modal contrastive learning and masked data for reconstruction. However, due to task competition and information interference caused by significant differences between the inputs of the two proxy tasks, the effectiveness of representation learning for intra-modal and cross-modal features is limited. In this paper, we propose an efficient VLP framework named Masked Contrastive and Reconstruction (MCR), which takes masked data as the sole input for both tasks. This enhances task connections, reducing information interference and competition between them, while also substantially decreasing the required GPU memory and training time. Moreover, we introduce a new modality alignment strategy named Mapping before Aggregation (MbA). Unlike previous methods, MbA maps different modalities to a common feature space before conducting local feature aggregation, thereby reducing the loss of fine-grained semantic information necessary for improved modality alignment. Additionally, due to using only masked input, our method significantly reduces the gpu memory and time required for training. Qualitative and quantitative experiments conducted on the MIMIC-CXR dataset validate the effectiveness of our approach, demonstrating state-of-the-art performance in medical cross-modal retrieval tasks.

提出了一种名为蒙版对比与重建（MCR）的高效VLP框架，以蒙版数据作为两个任务的唯一输入，增强任务之间的连接，并显著减少所需的GPU内存和训练时间。通过映射不同的模态到一个公共特征空间，然后进行局部特征聚合，减少细粒度语义信息的损失，从而降低了fine-grained的模态对齐所需要的gpu内存和时间。在MIMIC-CXR数据集上进行的定性和定量实验验证了该方法的有效性，并展示了在医学跨模态检索任务中的最先进性能。

跨模态医学图像-报告检索的掩码对比重建