Overview of the instruction. I was instructed to provide an expert report on liability, encompassing both breach of duty and causation, in a clinical negligence matter concerning the radiological imaging in a case where a vascular complication with associated neurological injury subsequently developed. My opinion was based on analysis of the medical notes and the imaging provided to me.

Medical specialty and issues considered. The matter fell within radiology. The issues included whether the imaging undertaken was interpreted to a reasonable standard; whether a different imaging modality should have been performed given the clinical picture; what an alternative investigation would more likely than not have shown; and whether the communication of imaging findings to the treating team was adequate.

Expert assessment and methodology. I began by setting out the role and limitations of the relevant imaging modalities, so that the standard of interpretation and the appropriateness of modality choice could be assessed objectively. I reviewed the imaging and the contemporaneous records, and reasoned separately about breach and causation. On breach, I considered whether the interpretation and the choice of investigation fell within the range expected of a reasonable body of radiologists, judged on the information available at the time. On causation, I reasoned about what a different or correctly interpreted investigation would more likely than not have demonstrated. I expressed my conclusions by reference to the balance of probabilities and distinguished fact from opinion throughout.

Key medico-legal considerations. The matter illustrates several principles central to expert practice: that breach must be judged against the standard of a reasonable body of practitioners and without hindsight; that breach and causation are distinct questions; that causal reasoning must consider what a different investigation would probably have shown; and that the communication of findings is part of safe practice. I confined my opinion to my own specialty and identified where other expertise would be required.

General learning points. For instructing professionals, the matter demonstrates the value of an opinion that separates interpretation from modality choice and breach from causation, reasoning transparently from the images and records. For clinicians and radiologists, it reinforces the importance of matching imaging to the clinical question and communicating findings clearly.

Throughout, I treated the interpretation of the study actually performed and the appropriateness of the modality chosen as separate questions, since each engages the standard of care in a different way. I reasoned about what a more definitive investigation would more likely than not have demonstrated, and I addressed how the findings were, or should have been, communicated to the treating team, recognising that accurate interpretation and clear communication are both integral to safe radiological practice. Approaching the matter in this structured way allowed me to identify exactly where, on the evidence, the standard expected of a reasonable body of radiologists was or was not met, and what the likely consequences of any departure would have been.

Professional value of the expert's involvement. My role was to provide an independent, transparent and evidence-based analysis, consistent with my overriding duty to the court. By setting out the role of each modality, reasoning about breach and causation separately, and expressing conclusions on the balance of probabilities, the opinion clarified the real issues and supported proportionate decision-making.