Magnetic Resonance Imaging

Magnetic Resonance Imaging (MRI) is a diagnostic method that creates detailed images of the internal parts of the body by using powerful magnetic fields and radio waves. It allows for the non-invasive and safe visualisation of organs, tissues, and other structures without the use of ionising radiation, making it appropriate for several diagnostic purposes.

How does MRI work?

1. Magnetism: When patients are placed inside an MRI machine, the protons in their bodies align with the machine’s intense magnetic field.
2. Radiofrequency pulses: Short bursts of radiofrequency pulses are delivered into the body, temporarily disrupting proton alignment.
3. Relaxation and signal detection: The protons return to their normal alignment after the radiofrequency pulses are switched off, releasing energy in the process. The receiver coils of the MRI machine detect this energy, and the data is used for constructing detailed images of internal structures.

Applications of MRI

1. Brain Imaging: MRI is widely used to examine the structure and function of the brain, assisting in the diagnosis and evaluation of various neurological illnesses such as brain tumours, multiple sclerosis, strokes, and Alzheimer’s disease.
2. Musculoskeletal imaging: MRI is useful for evaluating joint and soft tissue injuries, including ligament tears, cartilage damage, and muscle strains.
3. Imaging of the abdomen and pelvis: MRI gives vital information about the structures in the abdomen and pelvis, which aids in diagnosing illnesses such as liver disease, renal abnormalities, and reproductive disorders.
4. Cardiac imaging: Cardiac MRI may assess the anatomy and function of the heart, which can aid in detecting cardiac illnesses, congenital heart defects, and cardiac muscle damage.
5. Angiography: MRI can visualise blood arteries without intrusive treatments by utilising a specific contrast agent, assisting in studying blood flow and vascular anomalies.
6. Functional MRI: This specialised technology can detect variations in blood flow to identify brain activity, allowing researchers to examine brain function in response to various stimuli or tasks.

One of the major benefits of MRI is that it does not employ ionising radiation, making it a safe imaging method, especially for pregnant women and children. However, MRI may not be appropriate for those with certain medical devices, such as pacemakers or metallic implants, because the intense magnetic fields can interfere with these devices. Alternative imaging techniques, such as CT scans, may be employed.