How is MRI done?

Magnetic Resonance Imaging (MRI) is a sophisticated imaging technique that uses powerful magnetic fields and radio waves to create detailed images of the inside of your body. Here's a breakdown of the process:

The Principles of MRI

At its core, MRI relies on the behavior of hydrogen protons, which are abundant in the human body, particularly in water molecules. These protons possess a property called "spin," which gives them a magnetic moment.

Alignment with the Magnetic Field

• First, the patient is placed inside a powerful MRI machine.
• This machine generates a strong magnetic field, thousands of times stronger than the Earth's magnetic field.
• This strong magnetic field forces the hydrogen protons in the body to align, either parallel or antiparallel, to the field. This is the crucial first step.

Radiofrequency Pulse

• Next, a radiofrequency current is pulsed through the patient.
• This pulse is designed to match the resonant frequency of the aligned protons.
• The pulsed radiofrequency causes the protons to absorb energy and spin out of equilibrium, straining against the pull of the magnetic field.

Relaxation and Signal Detection

• When the radiofrequency pulse is switched off, the protons relax and return to their aligned state.
• During this relaxation, the protons release the absorbed energy in the form of a signal.
• The released signal is detected by the MRI machine.
• This signal varies depending on the type of tissue, which allows the machine to generate detailed cross-sectional images.

Key Components of MRI

Practical Application

The MRI process is non-invasive and does not involve ionizing radiation, making it a safe method for detailed medical imaging. It is particularly useful for visualizing soft tissues like the brain, spinal cord, joints, and internal organs.