This study explores the consequences of the uptake of novel medical technology for expertise coordination among specialists. Building on a 40-month field study, we show how the introduction of iMRI triggered a significant change in temporal, interactional and role dimensions of coordination. We trace the origin of those changes to the novel role the images started to play in surgery: iMRI generated new forms of visibility of the brain (offering real-time, more precise imaging) and new forms of ambiguity for clinical action (representing the brain undergoing manipulation). In response to this dual nature of images, specialists reconfigured how they engage with each other: aligning temporal rhythms of their corresponding work practices, shifting their interactions to focus more on dialog and synchronous mutual exploration of images, and delegating increased weight to radiological judgement for guiding immediate surgical action. We discuss the implications of our findings for research on expertise coordination and on the consequences of novel medical technologies for situated practice. © 2021 The Authors