Urgent diagnostic imaging and consent: A comparative review of Australian law and policy

INTRODUCTION: Consent is a fundamental requirement of lawful medical care in Australia, grounded in common law and jurisdiction-specific statutes governing decision-making capacity and substitute decision-making. These frameworks assume stable capacity, access to support persons, and time for discussion. Urgent diagnostic imaging in emergency and critical care settings rarely occurs under these conditions. Patients may present with pain, distress, intoxication, altered consciousness, or fluctuating capacity, and substitute decision-makers are often unavailable. Despite these realities, urgent imaging is commonly treated as ancillary to urgent care rather than as a distinct consent context. METHODS: A legal and policy review was conducted to examine how Australian States and Territories regulate consent and decision-making capacity in urgent treatment contexts and the implications for urgent diagnostic imaging. Legislation, health department policy instruments, tribunal guidance, and medico-legal scholarship were analysed across all eight jurisdictions. Comparative analysis identified similarities and differences in supported decision-making provisions, substitute decision-maker authority, and emergency treatment authorisation. RESULTS: The analysis identified convergence in core legal principles across jurisdictions, including functional models of capacity and recognition of urgent treatment authority. However, substantial variation exists in implementation. Jurisdictions differ in supported decision-making obligations, procedural safeguards, substitute decision-maker hierarchies, and reliance on statute versus policy guidance. These differences influence how urgent imaging is authorised, delayed, or refused in practice. Across jurisdictions, diagnostic radiographers frequently operationalise consent at the point of imaging, although their role is rarely recognised in legislation or policy. CONCLUSION: Australian consent frameworks share common ethical foundations but vary in implementation. These differences shape how consent is interpreted in urgent diagnostic imaging. IMPLICATIONS FOR PRACTICE: Imaging-specific guidance may clarify consent expectations in urgent settings and better support diagnostic radiographers working in time-critical environments.