INTRODUCTION The ideal imaging technique would be harmless, widely available, cost efficient, highly diagnostic and reliably repeatable. It should provide excellent multiplanar capabilities and good spatial resolution, while simultaneously identifying all foci of disease involvement that require treatment near and far from the primary presentation site. Unsurprisingly, this single utopian test does not currently exist, although, across a range of modalities in usage, there is a calculated compromise to be struck with individual test strengths balanced against specific weaknesses and side effects (Table 45.1). Modern imaging continues to improve and can potentially act as a surrogate marker for pathological tissue diagnoses, select surgical from non-surgical candidates and also help to prognosticate. Through modern electronic radiological systems, today’s surgeon is increasingly exposed to these newer diagnostic and interventional practices including guidance systems. In specific instances, image guidance can help to deliver non-surgical efficacious treatments (fluoroscopic salivary intervention, radiofrequency ablation, intra-arterial chemotherapy etc.). Functional imaging methods, such as positron emission tomography/computed tomography (PET-CT) and diffusion-weighted imaging (DWI) for neoplasia, can reflect cell turnover, metabolic consumption, vascular patterning and biological behaviour and this discipline will provide useful adjuncts to conventional anatomical images.