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Magnetic Resonance Imaging (MRI) creates images of the inside of the body using powerful magnets, radio waves, and computers. Here's how it works in simple steps:
In summary, MRI uses magnetic fields and radio waves to manipulate hydrogen atoms in the body, then detects the signals they emit to create detailed images of internal structures.
- Strong Magnetic Field: The MRI machine creates a very strong magnetic field, usually about 10,000 times stronger than Earth's magnetic field. This magnetic field aligns the protons (tiny particles) in the body, specifically those in the hydrogen atoms, because our bodies are mostly made up of water (which contains hydrogen).
- Radio Waves: Once the protons in the body align with the magnetic field, the MRI machine sends a pulse of radio waves into the body. This energy knocks the protons out of alignment with the magnetic field.
- Proton Relaxation: After the radio wave pulse is turned off, the protons begin to return to their original alignment. As they do this, they release energy in the form of radio signals.
- Detection of Signals: The MRI machine has detectors that pick up these radio signals emitted by the protons as they return to their aligned state.
- Creating Images: A computer analyzes these signals to determine the location and density of the protons in the body. Different tissues (muscles, fat, organs) have different densities of protons, so they emit different signals. By processing these signals, the computer can create a detailed image of the inside of the body, showing different structures.
- Image Reconstruction: The computer uses the data from the signals to construct cross-sectional images (slices) of the body. These slices can be combined to create 3D images, which help doctors see the organs and tissues clearly and identify any abnormalities.
In summary, MRI uses magnetic fields and radio waves to manipulate hydrogen atoms in the body, then detects the signals they emit to create detailed images of internal structures.