 If only we were all given a window so a doctor could look inside us when we were ill. Think of the operations that would save. Luckily, there are now many ways we can see what's happening deep inside our bodies by using electromagnetic waves and sound waves. So let's look at example techniques used in medical imaging. Infrared. This is a passive imaging technique. The infrared camera merely detects heat given off by the patient. Detecting local variations in skin temperature may show regions with poor circulation or the presence of tumours. A slightly raised temperature can be a quick check for illness before symptoms have appeared. This is useful for scanning crowds in an airport for example. There is zero risk unless you drop the camera on your foot. X-rays. These are good at penetrating the body. Skeletal structures absorb most X-rays and softer tissue much less. Images are captured by exposing photographic film which is a little old fashioned or as a digital image via charge coupled devices or CCD detectors. Much used in computerised tomography or CT scans which gives very high quality 3D images. There is a low risk to the patient but a high risk to the radiographer who wears protective clothing. X-rays are ionising electromagnetic waves and so are not suitable for everyone. For example pregnant women. They can show real-time images such as food being swallowed especially if the food contains an added heavy element such as barium in a so-called barium meal. Gamma rays. This technique uses short half-life radionuclides which are injected into the body and then their location or distribution is detected by the emitted gamma rays and mapped by external equipment. This can build up 3D image of internal organs. Some risk to all concerned in this case. Radio waves. Magnetic resonance imaging. Our MRI is now commonly used to produce high quality images of internal structures. It has a low risk to the patient. All the previous methods used electromagnetic waves but this one. Ultrasound. This uses a sound frequency well above the human hearing range. This technique relies on the emission and subsequent detection of ultrasound waves which penetrates soft tissue. They are reflected where organs change density and this echo is used to build up a low quality real-time image of organs and is commonly used in obstetrics to view the unborn baby. Quick, inexpensive, very low risk. Doctors don't really have superpowers but the machines they have can see right through you. Please like and share our videos with your friends. If you have any questions that you want help with just comment below.