MRIs are more useful in certain areas than CT scans. Discuss these areas.

Magnetic resonance imaging (MRI) can produce accurate and detailed pictures of the structures of the body and the brain, and it can distinguish between normal and abnormal tissue. MRI is more accurate than other imaging methods for detecting cancer that has spread to the bone, although positron emission tomography (PET)/computed tomography (CT) scans find cancer of the lungs more accurately. MRIs may be used for diagnosis and for the treatment of certain conditions that used to require surgery. For example, using MRI, radiologists can now clean or close off arteries without surgery. MRIs do not use radiation and are noninvasive. MRIs are used to image brain tumors and to help diagnose disorders of the nervous system, such as multiple sclerosis. MRIs also detect stroke at an earlier stage than other tests. MRIs can help find brain abnormalities in patients suffering from dementia. It is particularly useful with brain disorders because it can distinguish among different types of nerve tissue.
A new technique will attempt to use MRIs in combination with lasers to perform instant, bloodless, high-resolution biopsies. High-powered, pulsed lasers are focused on cells. This gives the cells the ability to glow. Computer software is then used to create a picture of the location of the beam and the fluorescence of the cells. Any change in the cell is seen. Because this technique cannot see far into the body, MRIs must be used for a complete picture.
For women at high risk for breast cancer, yearly MRIs and mammograms appear to save some lives. MRIs are not recommended for average women because of too many false positives. Breast tomosynthesis combines three-dimensional ultrasound and MRIs to create three-dimensional breast images. It can find tumors that are hidden