=Paper= {{Paper |id=Vol-3740/paper-164 |storemode=property |title=PCLmed: Champion Solution for ImageCLEFmedical 2024 Caption Prediction Challenge via Medical Vision-Language Foundation Models |pdfUrl=https://ceur-ws.org/Vol-3740/paper-164.pdf |volume=Vol-3740 |authors=Bang Yang,Yue Yu,Yuexian Zou,Tong Zhang |dblpUrl=https://dblp.org/rec/conf/clef/YangYZZ24 }} ==PCLmed: Champion Solution for ImageCLEFmedical 2024 Caption Prediction Challenge via Medical Vision-Language Foundation Models== https://ceur-ws.org/Vol-3740/paper-164.pdf
                         PCLmed: Champion Solution for ImageCLEFmedical 2024
                         Caption Prediction Challenge via Medical
                         Vision-Language Foundation Models
                         Bang Yang1,2 , Yue Yu1 , Yuexian Zou1,2 and Tong Zhang1,*
                         1
                             Peng Cheng Laboratory, Shenzhen 518055, China
                         2
                             ADSPLAB, School of Electronic and Computer Engineering, Peking University, Shenzhen 518055, China


                                        Abstract
                                        Automatically generating captions and reports for medical images has become increasingly important due to
                                        the growing workload of radiologists in hospitals. To tackle this challenging task with limited annotation data,
                                        there is a rising interest in developing medical vision-language foundation models (Med-VLFMs). These models
                                        leverage the capabilities of vision foundation models and large language models (LLMs) and often utilize the
                                        parameter-efficient fine-tuning (PEFT) technique. However, current Med-VLFMs face two critical issues: (1)
                                        relying on a single vision model to represent the semantics of medical images, and (2) adapting LLMs with
                                        PEFT without considering the interference between vision and text modalities. This work presents a novel
                                        Med-VLFM with vision encoder ensembling (VEE) and modality-aware adaptation (MAA) to address these
                                        limitations. VEE combines the strengths of general and medical specialist vision foundation models to produce
                                        a more holistic representation of medical images. MAA introduces two small sets of trainable parameters
                                        into LLMs to calibrate vision and text features, respectively. Our proposed Med-VLFM ranked 1๐‘ ๐‘ก on most of
                                        the automatic evaluation metrics, including BERTScore, ROUGE-1, BLEU-1, BLEURT, METEOR, CIDEr and
                                        RefCLIPScore, in the ImageCLEFmedical 2024 caption prediction challenge. Our code and models are available at
                                        https://openi.pcl.ac.cn/OpenMedIA/PCLmed24.

                                        Keywords
                                        Medical Image Captioning, Vision-Language Models, Medical Vision-Langauge Foundation Models, Parameter-
                                        Efficient Fine-Tuning, Vision Encoder Ensembling, Modality-Aware Adaptation




                         1. Introduction
                         Medical report generation (MRG), the main application of image captioning [1] in the medical domain,
                         stands as a pivotal task in healthcare, aiming to automatically produce precise and coherent reports
                         delineating the impressions and observations derived from medical images [2, 3, 4]. High-quality
                         cross-modal annotations, comprising meticulously paired medical image-report datasets, are essential
                         for the success of MRG. Despite the emergence of a few open-source datasets fostering research in
                         this domain [5, 6, 7], their limited scale poses significant challenges for the development of deep and
                         expansive neural architectures.
                            Recent advancements in vision and language applications have led to the rise of large-scale pre-
                         trained models, termed foundation models (FMs), designed for general applicability, and demonstrate
                         versatility across various tasks, owing to prompt engineering or parameter-efficient fine-tuning (PEFT).
                         The scalability of both model and data enables FMs to acquire emergent capabilities, empowering them
                         to tackle tasks previously deemed challenging for smaller models [8, 9, 10]. In the pursuit of effective
                         MRG, researchers have explored methodologies to harness the capabilities of FMs while addressing the
                         scarcity of labelled medical image-report pairs. One notable approach is the BLIP-2 architecture [11],
                         a state-of-the-art vision-language pre-training methodology that facilitates knowledge transfer from
                         single-modality vision and language foundation models.

                          CLEF 2024: Conference and Labs of the Evaluation Forum, September 09โ€“12, 2024, Grenoble, France
                         *
                           Corresponding author.
                          $ yangbang@pku.edu.cn (B. Yang); yuy@pcl.ac.cn (Y. Yu); zouyx@pku.edu.cn (Y. Zou); zhangt02@pcl.ac.cn (T. Zhang)
                          ย€ https://web.pkusz.edu.cn/adsp/ (Y. Zou)
                           0000-0003-2019-0377 (B. Yang); 0000-0002-8838-4963 (T. Zhang)
                                     ยฉ 2024 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).


CEUR
                  ceur-ws.org
Workshop      ISSN 1613-0073
Proceedings
   In this study, we present a novel approach to address the challenges in medical image captioning and
report generation using medical vision-language foundation models (Med-VLFMs). Drawing inspiration
from the BLIP-2 and its adaptations in the medical domain [11, 12, 13], our Med-VLFM incorporates a
lightweight query Transformer (Q-Former) to connect three foundation models (FMs): an ensemble of
EVA ViT-g [8] and BiomedCLIP [14] serving as the vision encoder, and Pangu-๐›ผ [15] as the language
decoder. Our proposed Med-VLFM introduces two innovative techniques: vision encoder ensembling
(VEE) and modality-aware adaptation (MAA). VEE combines general and medical specialist vision
foundation models to create a more comprehensive representation of medical images. MAA calibrates
vision and text features using small sets of trainable parameters in LLMs. Through experimentation
on the ImageCLEFmedical 2024 caption prediction challenge [16, 17], our Med-VLFM ranked 1๐‘ ๐‘ก on
most of the automatic evaluation metrics, including BERTScore, ROUGE-1, BLEU-1, BLEURT, METEOR,
CIDEr and RefCLIPScore, demonstrating the effectiveness of VEE and MAA in enhancing medical image
captioning and report generation.


2. Related Works
Medical/Radiology Report Generation Motivated by the rapid development of image captioning [1,
18, 19, 20, 21], the field of medical report generation has seen significant research interest in recent years.
Different from pure-text scenarios like chatting with patients [22, 23, 24] and discharge instruction
generation [25], medical report generation needs to โ€œtranslateโ€ medical images into detailed reports.
As such, one line of research focus on improving the cross-modal alignment between medical images
and reports, which is usually achieved by reinforcement learning [3, 26], contrastive learning [27, 28],
well-designed modules like hierarchical attention [29] and memory [30]. Given that generating accurate
reports requires domain expertise, another line of research opts to provide models with effective priors
through retrieval [3, 31, 32] or augment models with knowledge [28, 31, 33]. However, the language
models used in these medical report generation work are typically shallow and may lack the capacity
to capture the nuances of context and execute complex reasoning.

Medical Vision-Language Foundation Models Recent advancements in conversational AI have
shown promise in aiding biomedical practitioners. LLaVA-Med [34] proposes an efficient approach to
training a vision-language conversational assistant for answering biomedical image research questions.
Med-PaLM [35] provides high-quality answers to medical inquiries, while R2GenGPT [36] enhances
Radiology Report Generation by aligning visual features with language model embeddings. Addition-
ally, XrayGPT [37] introduces a conversational medical vision-language model for analyzing chest
radiographs. While these models signify significant progress in multimodal conversational AI for the
medical domain, their efficacy relies heavily on the quality and quantity of paired training samples. As
such, Med-MLLM [38] learns radiology representations from unlabelled data to quickly deploy tools
for rapid response to rare diseases. Despite the above efforts, the potential benefits of incorporating
multiple vision models have yet to be explored.

Parameter-Efficient Fine-Tuning With the proliferation of foundation models (FMs) [9, 10], effi-
ciently adapting FMs to a specific task becomes a research hotspot. One effective technique is prompt
engineering [39], which aims to affect the behaviors of language FMs by providing them with a textual
template filled with task-related priors [40, 41], demonstrations of several examples [42, 43], or a chain
of thoughts [44, 45, 46]. Alongside prompt engineering, parameter-efficient fine-tuning (PEFT) has
also emerged as a popular technique to influence the intermediate hidden states and final responses of
FMs. In implementation, PEFT either introduces lightweight components, e.g., Adapter [47], continuous
prompts [41, 48], and LoRA [49], vectors that scale the inner activations [50], into FMs, or adapts a
small portion of inherent weights of FMs [51]. Recent practices utilizing these two techniques have
demonstrated the effectiveness of adapting general-purpose FMs to the medical domain [52, 53, 54].
Distinct from these practices, our work focuses on medical report generation.
                         ็ŽฐไปฃไฟกๅทไธŽๆ•ฐๆฎๅค„็†ๅฎž้ชŒๅฎค
                       Advanced Data & Signal Processing Laboratory




            Framework Overview

                                                                                              Query Tokens
                                                                                                                               Input Text

                                                                                                     Q-Former                                      tied
                                                                                                                            LLM Embedding
                                            Vision
                                                                        LN
                                          Encoder 1
                                                                                              Visual Tokens                          Text Tokens

            Input                                                                                            Self-Attention
                                                                                                        Feed Forward Network
                                            Vision                                                  V-Adapter             T-Adapter
                                          Encoder 2                     LN
                                                                                              LLM with Modality-Aware Adaptation
           Frozen
           Trainable                                                                                                           LLM Head
           Concat                                          Vision Encoder Ensembling              Output Text Head CT demonstrating left parotiditis.


  Figure 1: Overview of our proposed Med-VLFM for medical/radiology report generation.
2024/6/1                                                                                ๆฑ‡ๆŠฅไบบ๏ผšๆจ้‚ฆ                                                                PKUSZ-SECE



  3. Approach
  Overview As shown in Figure 1, our proposed Med-VLFM for medical/radiology report genera-
  tion comprises four major components: vision encoders parameterized by ฮ˜๐‘ฃ = {๐œƒ๐‘ฃ1 , ๐œƒ๐‘ฃ2 }, a query
  Transformer (Q-Former) parameterized by ๐œƒ๐‘ž , a LLM parameterized by ๐œƒ๐‘ก , and modality-aware adap-
  tation parameterized by โˆ† = {๐›ฟ๐‘ฃ , ๐›ฟ๐‘ก }. Given the medical image ๐ผ and the target caption/report
  y = {๐‘ฆ1 , ๐‘ฆ2 , . . . , ๐‘ฆ๐‘ }, our model minimizes the following negative log-likelihood:
                                                                       ๐‘
                                                                      โˆ‘๏ธ
                                                             โ„’=โˆ’            log ๐‘(๐‘ฆ๐‘› |y