  Writing radiology reports from medical images requires a high level of domain
expertise. It is time-consuming even for trained radiologists and can be
error-prone for inexperienced radiologists. It would be appealing to automate
this task by leveraging generative AI, which has shown drastic progress in
vision and language understanding. In particular, Large Language Models (LLM)
have demonstrated impressive capabilities recently and continued to set new
state-of-the-art performance on almost all natural language tasks. While many
have proposed architectures to combine vision models with LLMs for multimodal
tasks, few have explored practical fine-tuning strategies. In this work, we
proposed a simple yet effective two-stage fine-tuning protocol to align visual
features to LLM's text embedding space as soft visual prompts. Our framework
with OpenLLaMA-7B achieved state-of-the-art level performance without
domain-specific pretraining. Moreover, we provide detailed analyses of soft
visual prompts and attention mechanisms, shedding light on future research
directions.
