Teachers’ notes for “seeing inside your body”
Mobile phones use radio waves at a similar energy to a microwave oven. This means that, it a mobile phone is left on close to your head, the signal could lead to your body warming up. Medical Physicists have made a computer simulation which calculates the amount by which the head will warm up. They found that the maximum change in temperature is about 0.2ºC.
Body temperature is about 37ºC and is held constant between about 36-38ºC unless there’s a problem like sunstroke or hypothermia. A change of 0.2ºC therefore appears to be quite significant. However, in practice, body temperature can change by this amount naturally, so an increase of 0.2ºC is probably safe.
Research like this has led to the Government recommending that children use mobile phones for emergency calls only.
This picture was taken from a thermal imaging camera and shows the warmest parts of the face in red/white and the coldest in blue.
The warmest parts are the eyes, forehead and lips, which are closest to the deep parts of the body core; the coldest are the nose, cheeks and chin which are the parts which stick out most.
The hair is particularly cold as it insulates the head and keeps the heat in.
Images like this are used to investigate parts of the body with poor circulation which feel cold, or regions of inflammation.
This is a 3D x-ray image of a foot, called a CT scan. A computer has processed the scan, identified the bone and the muscle and then rebuilt the image.
Another CT scan, this time of the pelvis. Again, a computer has identified the bones in the image and rebuilt the image.
This is a series of ultrasound scans taken of a foetus at 8, 18 and 24 weeks gestation.
At 8 weeks, you can see the head, arms and body surrounded by fluid (dark) and the placenta (a light fuzzy halo around the dark fluid). The baby is about 1cm long.
At 18 weeks, you can see the face, skull, ribs and heart. The baby is about 12cm long.
At 24 weeks, you can see the face, structures in the brain and the heart. If there’s a problem and the baby is born now, it will be about 4 months premature and will weight as much as a bag of sugar. This is the most premature that babies can be.
Ultrasound can do more than imaging babies. Here, it’s used to image the lips kissing! This work helps to treat people who have speech problems.
This is a different kind of scan again, called a PET scan. The patient is injected with a drug and the scanner measures where the drug went. If we choose a drug which is found in cancer, then we can work out where the cancer is.
This is a picture from a PET scan from somebody who’s been injected with a drug which flows round the blood stream and collects in a cancer. The heart and kidneys show up bright, because that’s where there’s a lot of blood, and the very bright region is a tumour.