Imaging describes a variety of techniques that noninvasively produce images of the internal aspect of the body. The term noninvasive is based on the fact that these medical imaging modalities do not penetrate the skin physically.
We use several techniques routinely in our hospital:
- Ultrasonography which uses high frequency sound waves which create echoes inside the tissues to show the internal structure. Ultrasound is used mostly for problems within the abdomen (belly) and the chest, especially the heart, although it also may be useful for looking at the eye, and less commonly limbs.
- Digital radiography uses X-ray radiation which is absorbed at different rates in different tissue types such as bone, muscle and fat, creating an image on a film or digital sensor which can then show us internal structures. This is especially useful for bony structures and the chest, but also has a role in looking at the abdomen.
- Endoscopy means looking inside, and typically refers to looking inside the body using an instrument to examine the interior of a hollow organ or cavity of the body. The most common example of this is using an endoscope to look into the gut down the oesophagus, through the stomach, and into the intestines. Biopsies can then be obtained of any organ visualised in this way. We also use these instruments for looking in other cavities.