=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==
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 ๐ก 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 09โ12, 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-๐ผ [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 ๐ก 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 โtranslateโ 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.
็ฐไปฃไฟกๅทไธๆฐๆฎๅค็ๅฎ้ชๅฎค
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 ๆฑๆฅไบบ๏ผๆจ้ฆ 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 ฮ๐ฃ = {๐๐ฃ1 , ๐๐ฃ2 }, a query
Transformer (Q-Former) parameterized by ๐๐ , a LLM parameterized by ๐๐ก , and modality-aware adap-
tation parameterized by โ = {๐ฟ๐ฃ , ๐ฟ๐ก }. Given the medical image ๐ผ and the target caption/report
y = {๐ฆ1 , ๐ฆ2 , . . . , ๐ฆ๐ }, our model minimizes the following negative log-likelihood:
๐
โ๏ธ
โ=โ log ๐(๐ฆ๐ |y