CT scan vs. MRI: What’s the Difference

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Alisha John

The difference between CT scan and MRI scan is the imaging technique used. CT scans provide detailed internal body images using X-rays, while MRIs use strong magnets and radio waves instead of X-rays. Both types of scans have a similar purpose in medical diagnostics but vary in imaging.

Physicians use both CT scans and MRIs to look at structures inside the body and take clear pictures for finding problems like fractures, stones in the kidneys, lumps, harm to joints or dislocated bones. The ability to see specific details within body tissues makes MRIs superior to other diagnostic methods. On the contrary, CT scans are widely available and cheaper than those produced by MRI machines.

What is CT scan?

CT Scan

CT stands for computed tomography. It is a method that is used by medical professionals to detect diseases or injuries as well as abnormalities. The result is a three-dimensional image of what lies within your body along with one picture that captures a particular segment.

Just like the doughnut-shaped tube during the CT scan, it revolved around the patient’s frame 360 degrees with regards to their different parts. Because certain tissues absorb more X-rays than others due to their density differences; then this situation leads to an X-ray image that would be whiter in case of denser areas.

CT scan with Contrast

Occasionally, doctors will use contrast agents or dyes during these procedures in order to highlight certain features on the images. Depending on your disease type and why you need scanning; either you drink it or else it’s injected into your veins through IV by your doctor. Subsequently urine is excreted out together with contrast media from your system.

CT scan is used to find the following:

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

Disadvantages of CT scan

  • CT scan requires the patients to hold their breath which is difficult for some patients.
  • CT scan of brain van de disturbed due to bones nearby.
  • CT scans 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?


Magnetic Resonance Imaging (MRI) is an examination in which powerful magnets and radio waves are used to produce detailed and clear images of the internal parts of the body. The apparatus is a big tube with strong magnets, within which the patient lies. Depending on what part of the body that will be scanned under MRI, then patient will be moved into the tube.
Additionally, this technique can distinguish among various tissues because of different protons. . Indeed, any tissue or organ in the body can be examined by a doctor using MRI. The procedure doesn’t cause any pain. It sees inside the parts of bodies including:

  • Brain and spinal cord
  • Joints and bones
  • Blood vessels and heart
  • Other internal organs, such as the stomach and 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 compared to a CT scan.
  • It is a time taking process.
  • It’s not very useful for claustrophobic patients as they have to lie inside the tube for a long time.
  • MRI cannot recommend for 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 a costly 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 quickly 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 precise 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.

Frequently Asked Questions

Which is more preferable between CT scan and an MRI?

The election between CT scan and MRI depends on the body part being scanned, why it is being done, and things about the patient.

Do CT scans have less risk than MRIs?

CT scans emit ionizing radiations while MRIs do not use x-rays making them safer in terms of radiations hazards.

Can I get both a CT scan as well as an MRI?

In some situations, both imaging methods can be necessary to provide full evaluations of certain medical conditions.

Are CT scans or MRIs painful?

None of these procedures are typically painful although patients may experience some discomfort from remaining still during examination time.

How long does it take for results from a CT scan or MRI?

Typical availability for results after a CT scan is done is shortly afterwards whereas MRI images take longer since there would be need for interpretation by a radiologist.


  • https://en.wikipedia.org/wiki/CT_scan
  • https://en.wikipedia.org/wiki/Magnetic_resonance_imaging