Magnetic Resonance Imaging (MRI)

Magnetic Resonance Imaging (MRI) is a non-invasive medical imaging technique that provides high-resolution images of internal body structures, especially soft tissues such as the brain, spinal cord, muscles, and internal organs.

MRI is based on the following components:

• A strong magnetic field aligns hydrogen nuclei (protons) in the body.
• Radiofrequency (RF) pulses disturb this alignment.
• As protons return to their original alignment, they emit signals.
• These signals are detected and processed into detailed images.

• No ionizing radiation.
• Excellent soft tissue contrast.
• Multiplanar capabilities (axial, sagittal, coronal, oblique).
• Functional and contrast-enhanced imaging options.

• Neurology: stroke, tumors, multiple sclerosis, epilepsy, trauma
• Spine: disc herniation, myelopathy, spinal tumors
• Musculoskeletal: ligament/tendon injuries, joint disorders
• Cardiology: myocardial viability, congenital heart disease
• Oncology: tumor detection, staging, and follow-up
• Abdominal imaging: liver, kidneys, uterus, prostate, pancreas

• Gadolinium-based agents are used to enhance vascular structures and highlight pathology.
• Usually safe, but used cautiously in patients with severe renal impairment (due to risk of nephrogenic systemic fibrosis).

• Metallic implants, pacemakers, or ferromagnetic fragments may pose risks.
• Claustrophobia may require sedation or use of open MRI systems.
• Long acquisition times compared to CT.

• fMRI (Functional MRI)
• MR angiography (MRA)
• Diffusion-weighted imaging (DWI)
• Perfusion MRI
• MR spectroscopy (MRS)

See also:

• Computed Tomography (CT)
• Positron Emission Tomography (PET)
• Neuroimaging techniques