The reason for the imaging request should be stated on the referral form to allow the most appropriate imaging technique to be used. It may be helpful to discuss the clinical problem with a radiologist. Most hospitals in the UK now use a picture archiving and communication system (PACS) to store X-ray, computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound examination images directly onto the hospital computer system. This chapter discusses X-ray imaging that includes chest X-ray and abdominal X-ray, and CT scanning that includes CT head, CT cervical spine, CT chest, and CT abdomen. Nuclear medicine techniques are useful in searching for occult foci of infection by the administration of radioactive labelled white blood cells. Doppler ultrasound uses alterations in reflection of the ultrasound beam by flowing blood cells and can be used to assess either arterial or venous flow.