Performance of Multimodal GPT-4V on USMLE with Image: Potential for Imaging Diagnostic Support with Explanations
Authors: Yang Zhichao , Yao Zonghai , Tasmin Mahbuba , Vashisht Parth , Jang Won Seok , Ouyang Feiyun , Wang Beining , Berlowitz Dan , Yu Hong 
Published: October 2023

Background

Using artificial intelligence (AI) to help clinical diagnoses has been an active research topic for more than six decades. Past research, however, has not had the scale and accuracy for use in clinical decision making. The power of AI in large language model (LLM)-related technologies may be changing this. In this study, we evaluated the performance and interpretability of Generative Pre-trained Transformer 4 Vision (GPT-4V), a multimodal LLM, on medical licensing examination questions with images.

Methods

We used three sets of multiple-choice questions with images from the United States Medical Licensing Examination (USMLE), the USMLE question bank for medical students with different difficulty level (AMBOSS), and the Diagnostic Radiology Qualifying Core Exam (DRQCE) to test GPT-4V’s accuracy and explanation quality. We compared GPT-4V with two state-of-the-art LLMs, GPT-4 and ChatGPT. We also assessed the preference and feedback of healthcare professionals on GPT-4V’s explanations. We presented a case scenario on how GPT-4V can be used for clinical decision support.

Results

GPT-4V outperformed ChatGPT (58.4%) and GPT4 (83.6%) to pass the full USMLE exam with an overall accuracy of 90.7%. In comparison, the passing threshold was 60% for medical students. For questions with images, GPT-4V achieved a performance that was equivalent to the 70th - 80th percentile with AMBOSS medical students, with accuracies of 86.2%, 73.1%, and 62.0% on USMLE, DRQCE, and AMBOSS, respectively. While the accuracies decreased quickly among medical students when the difficulties of questions increased, the performance of GPT-4V remained relatively stable. On the other hand, GPT-4V’s performance varied across different medical subdomains, with the highest accuracy in immunology (100%) and otolaryngology (100%) and the lowest accuracy in anatomy (25%) and emergency medicine (25%). When GPT-4V answered correctly, its explanations were almost as good as those made by domain experts. However, when GPT-4V answered incorrectly, the quality of generated explanation was poor: 18.2% wrong answers had made-up text; 45.5% had inferencing errors; and 76.3% had image misunderstandings. Our results show that after experts gave GPT-4V a short hint about the image, it reduced 40.5% errors on average, and more difficult test questions had higher performance gains. Therefore, a hypothetical clinical decision support system as shown in our case scenario is a human-AI-in-the-loop system where a clinician can interact with GPT-4V with hints to maximize its clinical use.

Conclusion

GPT-4V outperformed other LLMs and typical medical student performance on results for medical licensing examination questions with images. However, uneven subdomain performance and inconsistent explanation quality may restrict its practical application in clinical settings. The observation that physicians’ hints significantly improved GPT-4V’s performance suggests that future research could focus on developing more effective human-AI collaborative systems. Such systems could potentially overcome current limitations and make GPT-4V more suitable for clinical use.

1-2 sentence description

In this study the authors show that GPT-4V, a large multimodal chatbot, achieved accuracy on medical licensing exams with images equivalent to the 70th - 80th percentile with AMBOSS medical students. The authors also show issues with GPT-4V, including uneven performance in different clinical subdomains and explanation quality, which may hamper its clinical use.