Magnetic Resonance Imaging (MRI)
Magnetic Resonance Imaging (MRI) is a widely used medical imaging technique that employs a specialized device to capture detailed cross-sectional images of various body parts. This method relies on the magnetic properties of the human body, which contains millions of hydrogen ions that behave like a large magnet when subjected to the magnetic field produced by the MRI machine. As a result, the body emits signals that are converted into images displayed on a computer screen. MRI is particularly effective for imaging soft tissues, including the brain, gallbladder, ligaments, cartilage, spinal cord, uterus, ovaries, breasts, and blood vessels. The diagnostic process typically takes between ten and sixty minutes.
There are different types of MRI machines, including closed and open MRI systems. Closed MRI machines generally produce clearer, higher-quality images and allow for various applications such as diffusion tracking, spectroscopy, and other uses that require a strong magnetic field.
Risks Associated with MRI
The MRI technique is prevalent worldwide and uses a non-harmful magnetic field and radio waves, unlike X-ray or CT imaging. Notably, MRI has not been shown to cause any known side effects for pregnant women. While most individuals experience no adverse reactions to MRI, some may encounter the following issues:
- Allergic reactions to contrast dye or injections used during imaging, leading to symptoms like hives or eye itching.
- Side effects from the contrast agent, which may include nausea, headaches, and discomfort at the injection site. In rare instances, a person may develop a rash or experience itching in the eyes.
- Movement of metallic objects within the body due to the magnetic field, which could result in injury.
- Damage to implanted medical devices, such as pacemakers and pumps, making MRI unsuitable for certain individuals.
Contraindications for MRI Use
While MRI is generally safe, its use is restricted for individuals with metallic medical devices in their bodies. Below are scenarios where MRI should not be performed.
Absolute Contraindications
The following conditions are absolute contraindications for MRI:
- Presence of a pacemaker within the body.
- Any foreign metallic object lodged in the eye.
- Use of Triggerfish contact lenses, which continuously monitor intraocular pressure.
- Implementation of insulin pumps.
- Use of the LINX device, which is a series of titanium beads that create a magnetic field to manage gastroesophageal reflux disease (GERD).
Relative Contraindications
Relative contraindications for MRI include:
- Epidural catheters.
- Feeding tubes.
- Cochlear implants.
- Prosthetic heart valves.
- Drug infusion pumps for oncology or narcotics.
- Foley catheters with temperature sensors.
- Devices used to expand breast tissue.
Benefits of Magnetic Resonance Imaging
- No ionizing radiation is used during the procedure.
- Provides clear and accurate diagnoses for various conditions, particularly those affecting the heart, brain, spinal cord, and liver.
- Offers a comprehensive view of disease progression and development within the body, especially for cancers, muscle deformities, and joint and bone disorders.
- Safe for use in pregnant women and children without causing harm.
- Pain-free diagnostic experience during the scan.
Video on the Risks of MRI
While exposure to MRI can pose certain risks, it is essential to understand what potential harms may accompany the procedure.