There was a time in the not-too-distant past when “conventional” X-ray images were the only means of visualising the interior of the human body. “Imaging” was then called radiography and the study of the normal or diseased body was radiology. Oh yes, we did sometimes have images (‘scans’) taken after injecting radioactive isotopes.

Computerised Tomography (CT) marked the beginning of the present era and was followed by a number of better techniques. Conventional X-ray imaging still remains a common form of investigation.

The quest for less hazardous methods – both for the patient and the investigator also led to ultrasonography, which uses high frequency waves like sound waves. On the other hand, advances in physics led to the invention of magnetic resonance imaging (MRI) and a lot more.

Most imaging is necessarily an aid to diagnosis. Our main aim is a better understanding of normal anatomy through imaging. Technical aspects of imaging, which have been greatly simplified here, only serve to facilitate the understanding of the images.

The illustrations in this PowerPoint include only conventional X-ray images for explaining the principles. CT and MRI images will be shown in the laboratory.