Observer performance and eye movements in CT and MR multisectional imagery of stroke

Worldwide, radiology continues to evolve. Not only do imaging techniques advance and become more sophisticated, but factors affecting human health change with every decade. The continued advancement of medical images (their acquisition and interpretation) puts a strain on medical specialists, even before individual patient needs are considered. Factors that influence the ability of the reader to deliver patient needs depend on not only the image, but also the readers’ level of experience and expertise. Medical image acquisition, accuracy and interpretation have a hugely important role to play in patient safety. In neurology, referred patients are most frequently sent for computed tomography (CT) and magnetic resonance (MR) imaging of the brain to shed light on the origin and impact of disease. Whilst most observer performance studies focus on screening and detection of a few abnormalities in a non‐diseased population, the diseases of ‘older‐age’ are often neglected and treated reactively i.e. when a multitude of signs and symptoms appear, not necessarily as a preventive measure. Owing to the difficulty of measuring performance and the nature of expert interpretation when the technology itself is changing; neuroradiology has not been considered extensively from an observer performance perspective and studies concerning visual search in this area are very thin on the ground. Stroke is the focus of inquiry here for many reasons, but predominantly because urgent imaging of patients with quick feedback of image findings can reduce disability and save lives. If a further 10% of acute stroke patients received thrombolytic therapy within 3 hours of onset, over 1,000 people would regain independence per annum rather than rapidly deteriorate (DoH, 2006). Once treatment is administered and followed up effectively, patients can benefit from a further 5‐10 years of life (Indredavik, 1999; DoH, 2007). The benefits of further treatment within this population are known. What isn’t known is whether experts make errors of judgement within this clinical area, even if access to healthcare is increased.