Why use MRI

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Advantages :
Advantages of MRI include: 
  1. ability to image without the use of ionising x-rays, in contradistinction to CT scanning
  2. images may be acquired in multiple planes (axial, sagittal, coronal, or oblique) without repositioning the patient. CT images have only relatively recently been able to be reconstructed in multiple planes with the same spatial resolution
  3. MRI images demonstrate superior soft tissue contrast as compared to CT scans and plain radiographs making it the ideal examination of the brain, spine, joints, and other soft tissue body parts
  4. some angiographic images can be obtained without the use of contrast material, unlike CT or conventional angiography
  5. advanced techniques such as diffusion, spectroscopy and perfusion allow for precise tissue characterisation rather than merely 'macroscopic' imaging
  6. functional MRI allows visualisation of both active parts of the brain during certain activities and understanding of the underlying networks.

Disadvantages :
Disadvantages of MRI include: 
  1. MRI scans are more expensive than CT scans
  2. MRI scans take significantly longer to acquire than CT and patient comfort can be an issue, maybe exacerbated by:
    • MR image acquisition is noisy compared to CT
    • MRI scanner bores tend to be more enclosed than CT with associated claustrophobia
  3. MR images are subject to unique artifacts that must be recognised and mitigated against. 
  4. MRI scanning is not safe for patients with some metal implants and foreign bodies. Careful attention to safety measures is necessary to avoid serious injury to patients and staff, and this requires special MRI compatible equipment and stringent adherence to safety protocols.


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