ct scan vs MRI

Ct Scan Vs MRI, Important things to know for a patient


There are two tests that most commonly used when it comes to body scans, CT scans and MRIs. Both of these are vastly more efficient and detailed than x-rays and provide a much more detailed view of the human body. Thus making it easier for doctors to assess the ailment.

The question of which test is prescribed when has always been a source of confusion for patients.

Ct scan vs MRI Both these tests are designed to show the cross-sectional images of the body, but the means with which they do so are different.

CT scans, or computerized tomography uses a different variation of the old and reliable x-rays to produce an image.

MRI, magnetic resonance imaging, however, uses magnetic fields and radio frequencies to do the same. The difference in the techniques becomes the biggest factor when choosing a particular scan and one or the other is suggested by the doctor depending on the scan requirements.


What is a CT Scan?

This is a combination of a series of x-ray images taken at different angles. The scan uses a computer program to generate a complete image based on these x-rays. This scan is best used to view bone injuries, diagnosing lung and chest issues or for detecting cancers.


What is an MRI?

Magnetic resonance imaging, or MRI, does not use radiation and instead uses magnetic fields to produce an image of the body’s soft tissues and bones. This technique is used to identify ligament and tendon injuries, spinal cord injuries, brain tumors, etc.


Ct Scan Vs MRI The Difference

  • The main difference is the means by which the image is obtained. CT scans use radiation in the form of x-rays while MRI uses magnetic fields and radiofrequency pulses to produce detailed pictures of the organs.
  • MRI scans usually provide a far more detailed image of the soft tissues and internal organs such as the brain, skeletal system, reproductive system and other organ systems than that provided by a CT scan.
  • CT scans are quick and painless, although they do involve exposure to small amounts of radiation.
  • MRI scans are noisy, require more time and considering the fact that they are done in a small tube-like structure, they can cause some claustrophobia to those prone to it.
  • MRI scanners are costlier than CT scan machines.
  • MRI scanners use very strong magnets and may cause safety issues if there are metal objects around it when it is functioning.
  • A CT scan usually takes about 5 minutes, out of which the actual scan time may just be about 30 seconds. It is less sensitive to the patient’s movement.
  • An MRI usually takes from 15 minutes to 2 hours depending upon the type of scan. They are highly sensitive to the movement of the patient and even the slightest of motion can disturb the image.
  • MRI scans are more expensive than CT scans.
  • CT scan can pose the risk of radiation exposure, but re painless and non-invasive.
  • MRI scans have no reported biological hazards, but some people may be allergic to the contrast dye which needs to be ingested prior to the scan. This may be dangerous for those suffering from liver or kidney disorders.


Scans According to Body Parts

  • Abdominal Pain – In cases of abdominal pain, the preferred test is considered to be a CT scan. It is easily accessible for emergencies and has a high accuracy rate. Ultrasound scans are usually used for children and pregnant women.
  • Trauma – Most emergency departments have a CT scan machine on hand and it is the best option to see any bone trauma or blood and organ injury.
  • Spine – MRI imaging is considered to be the best option for creating images of the spinal cord and nerves.
  • Brain – CT scans are used when speed is of primary importance. This is most often the case for trauma or strokes. MRI is best used when there needs to be a detailed image in case the doctor is looking for cancer, causes of dementia, neurological diseases, or if the doctor is looking for a place where the bone might be interfering.
  • Chest – CT scans are the most effective when one needs to examine lung tissue and are often used to follow up on abnormal chest x-rays. Low dose CT scans are also available for high-risk smokers who need to be scanned annually.
  • Joints – MRI is the best scan for joints, tendons, and ligaments.


Reasons to Perform a Ct scan abdomen

When the doctor suspects that there is some issue with the abdominal region of the patient, but falls short of information during the physical examination, a CT scan abdomen is ordered. Below are some of the reasons why an abdominal CT might be prescribed:

  • Unexplained abdominal pain
  • A prominent mass in your abdomen
  • To check the size of suspected kidney stones
  • Unexplained weight loss
  • Infections
  • Checking for intestinal obstruction
  • Inflammation of intestines (Crohn’s disease)
  • Injuries/trauma
  • Cancer


Which is Safer, CT or MRI?

Ct scan vs MRI both these scans are considered to be relatively safe. There can, however, be unforeseen problems. If a patient has aneurism clips in the brain they should not be prescribed MRI scans, unless these clips are MRI safe. If these clips are pulled out because of the MRI strong magnetic field the patient can bleed into the brain. MRI scans are also not advisable for patients with pacemakers or defibrillators because MRI scanners can cause disruption of battery-operated devices. Metal should not be brought anywhere close to an MRI scanner. The strong magnetic field it creates can cause injuries and leave a patient in a worse state than what they have been brought in with.

CT scans, while widely considered safe, expose the human body to doses of radiation. While these are small amounts, if one is exposed to them on a regular basis they can cause greater problems going forward. There are also some types of CT scans which are considered inappropriate for pregnant women.

While both these scans have their own benefits and particular sets of uses, it is important to note that we at Regency Medical Center are very careful about advising scans. We make sure that we look at the patient’s case history and ailment thoroughly before advising any particular scan. It is this attention to detail that sets the service of RMC apart from other medical centres.



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