CT Scan vs. MRI – What’s The Difference

The main difference between CT Scans and MRI scans is the use of rays during the process.  CT scan uses X-rays, whereas strong magnetic fields and radio waves are used during MRI. Although both types of scans have similar uses and are related to disease diagnosis; however, the way they produce images is different.

CT scan and MRI help doctors to examine the internal body parts and doctors can see the detailed images to detect the abnormalities like fractures in bones, stones, tumors, joint damage, and dislocation of bones. MRI is used to produce better and detailed images of the internal part of the body; meanwhile, CT scans are more common and less expensive as compared to MRI.


What is CT Scan?

CT Scan

CT scan stands for computed tomography scan. It’s a diagnostic tool for the detection of disease, injury, and abnormalities. In CT scans, X-rays and computers are used to produce the 3D image of the body’s internal parts and produce the image of the cross-section of the body. As in the CT scan, the doughnut-shaped tube rotated the X-rays in 360 degrees around the body and provided the 3D view of the body parts. Due to different densities of body tissues, different tissues absorb different amounts of X-rays; therefore, the high-density tissues produce a whiter image as compared to low-density tissues.

CT Scan with Contrast

Sometimes physician uses a contrast agent also called a dye to improve the images by highlighting certain features. You either have to drink the contrast liquid or your physician use IV injections with the contrast depending upon the type of disease and the reason for the scan. The contrast liquid is then excreted out the body through the urine.


CT scan is used to find :

  • Cancer and benign (noncancerous) tumor.
  • Fractures
  • Heart disease
  • Injuries in the spinal cord and brain
  • Internal bleeding
  • Abnormalities in organs and tissues

Advantages of CT Scan

  • CT scan is less expensive as compared to MRI.
  • CT scan is very efficient for imaging bone structures.
  • Time Efficient
  • Results of CT scan can be improved by using contrast liquid.
  • CT scan provides a 3D image of the body by rotating X-rays in 360 degrees.

Disadvantages of CT scan

  • CT scan requires the patients to hold breath which is difficult for some patients.
  • CT scan of brain van de disturbed due to bones nearby.
  • CT scan can be dangerous for unborn babies. It can cause tumors or childhood cancer in babies.
  • Contrast liquid of CT scan can also damage the kidney.

What is MRI?


MRI (Magnetic resonance imaging) is a scan wherein strong magnetic fields and radio waves are used to provide a clear and detailed image of the internal parts of the body. It consists of a huge tube with powerful magnets, and the patient lies inside the tube. During MRI, depending upon the part of the body to be examined, the patient will be moved inside the tube.

MRI also can differentiate between various types of tissues, as MRI uses the protons of the body and different tissues have different protons so it can distinguish between them very easily. With MRI, doctors can examine almost any part of the body. It is a painless procedure. It examines the body parts, including

  • Brain and spinal cord
  • Joints and bones
  • Blood vessels and heart
  • Other internal organs such as stomach, liver.

Advantages of MRI

  • MRI produces more clear images than a CT scan.
  • It can scan almost every part of the body.
  • Unlike X-rays, it does not harm the body with any harmful rays.
  • MRI can create images of the body in almost all directions.
  • MRI is non-invasive technique.

Disadvantages of MRI

  • MRI is expensive as compared to a CT scan.
  • It is a time taking process.
  • It’s not very useful for claustrophobic patients as the patients have to lie inside the tube for a long time.
  • MRI cannot recommend to pregnant women.

Comparison chart between CT scan and MRI

Basis for Comparison CT scan MRI
Radiation exposure In CT scans, X-rays are used, which are not very useful for the body and can harm the body parts. In MRI strong magnetic field is used. It does not emit any ionization radiation.
cost CT scan is a less expensive process than MRI MRI is an expensive process.
Time taken CT scan can be done only in five minutes MRI takes a long time depending on the parts of the body to examine, ranging from ten to fifteen minutes.
Scope of applications CT can scan bone very easily and have good accuracy MRI is used to examine different parts of the body and body organs.
Sensitivity to motion CT scan is less sensitive to motion and gives results in less time MEI is highly sensitive to motion. Patients are supposed to make fewer movements during the process.


CT scan and MRI are two different techniques to examine internal body parts. They have similar uses, but they produce pictures in different ways. MRI gives better results and more clear images as compared to CT scans. MRI is a bit expensive process, and it’s also time taking. A doctor will recommend the scan according to the condition of the patient.

About Alisha John

A Nature Lover and Freelance Writer! I write about daily practices for optimizing both happiness and health.

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