CLIP-TNseg: A Multi-Modal Hybrid Framework for Thyroid Nodule Segmentation in Ultrasound Images

Thyroid nodule segmentation in ultrasound images is crucial for accurate diagnosis and treatment planning. However, existing methods struggle with segmentation accuracy, interpretability, and generalization. This letter proposes CLIP-TNseg, a novel framework that integrates a multimodal large model with a neural network architecture to address these challenges. We innovatively divide visual features into coarse-grained and fine-grained components, leveraging textual integration with coarse-grained features for enhanced semantic understanding. Specifically, the Coarse-grained Branch extracts high-level semantic features from a frozen CLIP model, while the Fine-grained Branch refines spatial details using U-Net-style residual blocks. Extensive experiments on the newly collected PKTN dataset and other public datasets demonstrate the competitive performance of CLIP-TNseg. Additional ablation experiments confirm the critical contribution of textual inputs, particularly highlighting the effectiveness of our carefully designed textual prompts compared to fixed or absent textual information.