MRI
MRI uses a very strong magnetic field to produce images of a patient's anatomy. This is accomplished by changing the alignment of the hydrogen atoms in a person's body. The magnetic field changes their alignment and as the strength of the magnetic field is lessened and the atom returns to its normal alignment energy is released by the atom. This energy is measured and sent to a computer where an image is created. However this process takes a considerable amount of time and that is why an MRI takes so long. Approximately 5 minutes per sequence and there are usually 4 sequences per exam. An advantage to MRI is that because it does not use radiation there are no harmful affects to the patient.
