Magnetic resonance imaging [MRI]
Magnetic resonance imaging [MRI]
Magnetic resonance imaging is an imaging technique that uses magnetism, radio waves and a computer to produce images of the internal organs of the body. The MRI scanner contains a very powerful magnet that produces very string magnetic fields. Our body contains hydrogen atoms and when exposed to very strong magnetic fields, these hydrogen atoms get aligned in a particular way. When radio waves are sent towards these hydrogen atoms, they bounce back and a computer records the signal. Based on the reflected radio waves, the images of the tissues is constructed.
MRI provides an unparalleled view of internal organs of the human body. It is the preferred imaging method of choice for many types of conditions because it can be tailored precisely for the medical question being asked. MRI can also be used to study the flow of blood in any part of the body. It can be used to distinctly image the arterial blood system without imaging the nearby tissues. In many cases, this can be done even without injecting a contrasting medium into the patient’s body.
MRI has many advantages. It does not use ionizing radiations and so is safe. Ionizing radiations are known to be harmful and may cause cancer. Also the contrast agents used in MRI scanning have low incidence of side effects. MRI is very versatile. It can be used to image both in the axial and sagittal planes and also coronally, without the patient having to move.
Despite its numerous advantages, there are certain restrictions on the use of MRI. For example, MRI cannot be used on persons implanted with pacemakers and other metal implants. Claustrophobic people, i.e. people with fear of confined spaces, may find the MRI scanning procedure very uncomfortable and disconcerting. MRI machines are also very expensive and so the exam is also very expensive. However, these disadvantages are easily outweighed by the numerous advantages that the MRI has.
Related pages:
- Medical Imaging
- Electrocardiogram [ECG]
- Electroencephalogram [EEG]
- How does ultrasound work?
- Ultrasound
- Computed tomography [CT Imaging]
- Positron emission tomography [PET]
- Commonly Used Radionuclides in Nuclear Medicine
