Test your knowledge:

1. X-ray CT scanners generate 3D pictures of objects but they don’t use special 3D cameras. They use regular 2D imaging devices. Explain briefly (3 – 5 sentences) how CT scanners can generate a 3D image from a set of 2D images.
2. While CT scans certainly produce incredibly detailed images, they’re only used for very serious medical conditions (you certainly wouldn’t get a doctor prescribing a CT scan to look at your broken arm for example). Explain why doctors only prescribe CT scans for serious conditions.
3. X-rays are part of the electromagnetic spectrum. Radiowaves, gamma rays and ultraviolet waves are also part of the electromagnetic spectrum. Place the following types of electromagnetic radiation in order of increasing energy (from lowest to highest).
   • Microwaves
   • hard x-rays
   • yellow light
   • radio waves
   • blue light
   • gamma rays
   • soft x-rays
   • infra-red
4. Just thinking about x-ray imaging in general (not necessarily CT scans) what are some applications of x-ray imaging besides medical imaging?