MRI uses a magnetic field and radio frequencies (RF) to acquire data that can be used to generate images on a computer. What happens in the MRI system and inside the body during image acquisition? A brief explanation is introduced below.
Before examination it is confirmed that no ferromagnetic materials are present.MRI systems generate a large magnetic field. It’s important to check whether there are any ferromagnetic materials on or inside the patient's body that could compromise image quality or pose a safety risk. Additionally, mechanical or electronic implanted devices may be contraindicated, and more information regarding these items will need to be obtained before the scan is performed.
After the patient lies in the MRI table, its properly positioned, and advanced into the MRI gantry, the entire body is exposed to a very strong, constant and homogeneous magnetic field.
Under this strong field, and after the application of RF waves, changes in the Hydrogen atoms in the body can be detected by using a special antenna, placed over the area being scanned.
After data acquisition, a powerful computer reconstructs the images which can then be displayed in a monitor for a physician to interpret.
The image is reconstructed.