What is an MRI?

MRI (Magnetic Resonance Imaging) is a technique used in medical imaging in radiology to make diagrams of anatomy and physical processes of the human body. MRI is a common imaging procedure that is used widely used all around the globe. MRI is a non-invasive imaging technology that is used to make detailed three-dimensional anatomical images. 

MRI is often used for the detection of diseases and tumors, diagnosis, and treatment monitoring. MRI uses powerful magnets, radio waves, and a computer, together all of these make a detailed image of your inside body. What differentiates MRI from computer tomography (CT) scans is that it does not utilize harmful X-rays and thus it does not use potentially harmful ionizing radiation. 

How does MRI work?

MRI stands for Magnetic Resonance Imaging and as the name suggests MRIs use powerful magnets which utilize a strong magnetic field that forces the protons in the body to align with the magnetic field. Bypassing a radiofrequency through the patient protons are stimulated and strained against the pull of the magnetic field. When the radiofrequency field is turned off, the protons realign with the magnetic field. Physicians are able to tell the difference between various types of tissues based on these magnetic properties.    

To obtain an MRI image, a patient is placed in a large magnetic tube and during the process, the patient must remain very still to obtain a proper image without any blurs. Contrast agents are given to the patient before MRI to obtain the brighter image of MRI and get better results of the imaging. 

What are the uses of MRI?

An MRI scan is an extremely accurate method to detect diseases and tumors throughout the human body. In the head MRI can be used for:

  • Swelling or internal bleeding in the brain
  • Brain strokes and tumors
  • Other abnormalities found in the brain

Neurosurgeons use an MRI scan for not only detecting the abnormalities in the brain but also to detect and evaluate the integrity of the spinal cord after trauma. 

Mostly MRI is best suited to image the soft tissues and the non-bony parts in our body. The brain, spinal cord, and the nerves, as well as the muscles and the ligaments, are seen much more clearly in MRI than in the CT scan. 

Following are examples for which MRI scan is used:

  • Tumors, cysts, and other anomalies in various parts of the body
  • Certain types of heart problems
  • Diseases of liver 
  • Breast cancer 


As magnets are used in the MRI, it is a must to not have any metal objects present during the scan. The doctors may ask you to remove your watch and jewelry and other metal accessories.

 If a person is having metal objects in his/her body or medical devices like pacemakers the person will not be able to have an MRI scan. 

Patients may sometimes receive an injection of contrast liquid to improve the visibility of a particular tissue and get better.