While live streaming for health communication is growing, viewership of medical livestreams (MLS) remains relatively low. Given the crucial role of visual elements in capturing audience attention, the title image of a medical livestream holds significant potential for increasing viewership. However, research on this topic remains scarce. To address this, we investigate how image narrative elements in title images of MLS affect viewership. We apply Narrative Transportation Theory to the healthcare context, extending the concept of narrative impact from text to images, and empirically examine its effects through four constructs: textual richness, background brightness, character presence, and emotional expression. By analyzing the title image of 22,257 live streams from Baidu Health, we find that textual richness and emotional expression significantly increase viewership, while a high level of background brightness and character presence significantly decrease the viewership of MLS, highlighting the importance of perceived professionalism in MLS. Furthermore, a doctor’s professional title and hospital ranking strengthen the positive effects of textual richness and emotional expressions, while weakening the negative effects of background brightness and character presence. This study offers new theoretical and practical insights into health communication on online platforms, contributing to both narrative style and online health communities literature.