What is the general principle that underlies computed axial tomography (CT)?

What is the general principle that underlies computed axial tomography (CT)?

What is the general principle that underlies computed axial tomography (CT)? 150 150 Peter

What is the general principle that underlies computed axial tomography (CT)? What are the advantages of CT images over conventional X-ray images?
Explain the general principle underlying magnetic resonance imaging (MRI)? What are the advantages of this method compared to older methods of imaging?
What role should the government play in the creation of standards?