Why in the news?

• Magnetic Resonance Imaging (MRI) revolutionized medical diagnostics, offering non-invasive insights into soft tissues.
• The pioneering efforts of Paul Lauterbur and Peter Mansfield led to its commercialization, earning them the Nobel Prize in Medicine in 2003.

What is MRI?

• Magnetic resonance imaging (MRI) is a non-invasive diagnostic procedure used to obtain detailed images of soft tissues within the body.
• It is particularly valuable for imaging sophisticated structures like the brain, cardiovascular system, spinal cord, joints, muscles, liver, and arteries.
• MRI is instrumental in diagnosing and monitoring various conditions, including cancer, neurological disorders (such as Alzheimer’s and stroke), and cardiovascular diseases.
• Functional MRI (fMRI) can also assess brain activity by monitoring changes in blood flow.

Working Principle:

• MRI utilizes the magnetic properties of hydrogen atoms (one proton with one electron around it), which are abundant in water and fat molecules found throughout the body.
• The MRI machine generates a powerful magnetic field, aligning hydrogen atoms within the body.
• Radiofrequency pulses are then applied, causing hydrogen atoms to absorb energy and emit signals.
• These emitted signals are detected by sensors and processed by a computer to create detailed images of the body’s internal structures.

Components of an MRI Machine:

The MRI machine consists:

• Superconducting Magnet: Large magnet (superconducting magnet) that produces a powerful and stable magnetic field.
• Gradient Coils: Gradient magnets produce smaller magnetic fields with varying strengths and directions, allowing for precise imaging of specific body areas.
• Radiofrequency Coils: This emit radiofrequency pulses to excite hydrogen atoms in the body. The frequency of pulse the ‘excess’ atoms have to absorb is called the Larmor frequency.
• Detectors: It capture emitted signals from hydrogen atoms and convert them into image data for analysis.

Advantages of MRI:

• High-Resolution Imaging: MRI offers high-resolution imaging with excellent tissue contrast, allowing for accurate diagnosis and treatment planning.
• Versatile Viewing Angles: It can visualize structures from various angles without the need for repositioning, providing comprehensive information.
• Safety and Non-Invasiveness: MRI scans are non-invasive and do not involve ionizing radiation, making them safe for repeated use.
• Enhanced Image Quality: Contrast agents can enhance image quality by highlighting specific tissues or abnormalities.

Limitations of MRI:

• High Costs: MRI machines are expensive to purchase and maintain, resulting in high healthcare costs for patients.
• Requirement for Patient Stillness: Patients undergoing MRI scans must remain still for extended periods to prevent image distortion, which can be challenging for some individuals.
• Discomfort or Anxiety: The strong magnetic fields and loud noises produced during MRI scans may cause discomfort or anxiety for patients.
• Limitations with Metallic Implants: Certain metallic implants or objects can interfere with MRI scans, limiting their use in individuals with such implants.

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