essay on radiation in medicine help please?

[courtneY. W]

im writing an essay and the topic is 'radiation - a vital part of modern medicine', so ive split it up into two categories - radiation therapy and radiology.
in radiology ive talked about the three different types of imaging - CT, MRI and ultrasound but MRI doesn't use radiation, it uses magnetic and radio waves. so should i include it in my essay even though it doesn't use radiation??
and also shoudl i use ultrasound because it uses sound waves?

[Crouching Doggie]

I think you've got it right... Don't include MRI or Ultrasound...

but add X-ray imaging (radiography), Nuclear Medicine (diagnostic), and Radiation Oncology/Therapy (therapeutic), as all these involve the use of ionizing radiation.