How is a MRI scan image produced?
Your body contains millions of hydrogen atoms. When you are in an MRI scanner: A strong magnetic field aligns particles called protons which are within the hydrogen atoms. All the protons line up in parallel to the magnetic field like tiny magnets. (Normally the millions of protons all lie in random directions.) Then, short bursts of radio waves are sent from the scanner into your body. The radio waves knock the protons from their position. When the burst of radio waves stops, the protons realign back into place. As they do so they emit radio signals. The protons in different tissues of the body realign at different speeds. Therefore, the signal emitted from different body tissues varies. So, for example, softer tissues can be distinguished from harder tissues on the basis of the signals sent. These signals are detected by a receiving device in the scanner. The receiving device transmits the signals to a computer. The computer creates a picture based on the radio signals emitted from t
