MRI is important because of the clarity with which it can illustrate different parts of the body, thus helping doctors with the correct diagnosis. It can determine the difference between healthy and diseased tissue, and can provide important information about the brain, spine, joints and internal organs.

Both MRI and CT create cross-sectional images of the body. The main difference is that MRI uses a large magnet and radio waves to produce images where as a CT scanner uses ionizing radiation. While CT can only directly acquire transverse and coronal images, MRI can directly acquire slices in any plane. MRI is also superior to CT when it comes to contrast imaging.

The time depends on the number of and type of scans required. It can last anywhere from as little as 15 mins to about an hour.

Since the MRI operates a strong magnetic field, you will be required to leave all items of clothing and accessories that contain metal behind before the scan.

Unlike CT or X-Ray, MRI does not use radiation to generate images. So the answer is no radiation

MRI scans are very safe. Unlike CT or X-Ray, MRI does not use radiation to generate images and therefore there is no exposure to radiation. However, since MRIs use strong magnets, people with certain devices like pacemakers and other implants cannot get an MRI.

For normal MRI scans that do not require contrast, injections are not required. However, if your physician has suggested that you get an MRI with contrast, then a pharmaceutical contrast agent called Gadolinium is administered to the patient through an injection. Contrast is used to make specific organs, blood vessels or tissue types "stand out" with more image contrast in the resulting picture.

Doctors usually avoid prescribing MRIs for pregnant women unless there is a strong medical indication for it.