The increasing demand for radiological services on the NHS in the United Kingdom has escalated clinical and administrative workloads for staff, challenging radiology departments to balance clinical duties with teaching time. However, the impact of these demands on the delivery of teaching in medical education remains underexplored. This chapter examines how the temporal demands of increased information and the complexities of interpreting modern imaging technologies such as MRI and CT have introduced new pressures in radiology education. Based on a video ethnography of x-ray image interpretation training, this chapter examines how radiologists manage these temporal challenges while teaching medical students during radiology rotations in an NHS teaching hospital. I show how chest x-ray image interpretation training has evolved into ‘whistle stop’ teaching, which operates as boundary work - enabling radiologists to manage time effectively by delineating what counts as essential knowledge for medical students and streamlining teaching practices under time pressure. Key strategies include prioritising chest x-ray instruction, structuring interpretation around expected abnormalities, and using spot diagnoses to expedite learning. This chapter argues that the increased detail and complexity of modern imaging necessitate new strategies for balancing teaching and clinical duties. Understanding these boundary work practices and how they are managed is essential for studying the temporal dynamics and the inclusion/exclusion of radiological knowledge in medical education.