Question: How does biology such as Gynaecology or Obstetrics link with Physics especialy imaging?

Tom Hartley answered on 16 Jun 2010:

This is a great question, francisca. These fields are linked by medical imaging, which is a topic you can study at A-level (if you do Physics). I could go on about this for ages. In gynecology and especially obstetrics the main imaging method is ultrasound, at least that’s been my experience as an expectant father. Some of the other techniques are a bit risky for a small and delicate developing human being (for example X-rays and CAT scans involve exposure to ionizing radiation). MRI (which I use in my research) is an important medical imaging technology because it doesn’t involve ionizing radiation. It produces better, more detailed pictures, which show soft tissues like the brain clearly, and which allow different tissues to be distinguished (because they have different magnetic properties) – some imaging methods are good for spotting bruising or tumours. MRI could be useful for some gynecological conditions, but I don’t think it would be used in pregnancy (certainly we don’t scan pregnant women for research purposes). I guess this is because the noise and (slight) heating effect effect produced by radio waves used in MRI might be stressful for a fetus, and we don’t want to take any chances.

MRI is great for brain science. You can see an MRI scan of my head on the profile page and there is a slightly gruesome 3D version on my blog. MRI can also be adapted to show blood-flow changes (fMRI) which helps us understand what the brain “does” as opposed to what it looks like. We can also look at how water diffuses (DTI) or how blood moves through the brain (arterial spin labelling).

All these techniques and others I haven’t mentioned (such as PET) depend on medical physics. People sometimes think of Physics as a mind-bending but abstract subject that has little relationship to everyday life. Wrong: medical imaging is a very important application of physics.