If your doctor advises an MRI or a CT scan, and you are confused about it. Then here you will get to know about that. A CT scan and an MRI both take pictures of your internal body to identify the situation and problems which you are facing. A CT scan takes pictures of tissues, organs and skeletal structure. MRI provides highly detailed images that help detect abnormalities. They are both completely different because some people think they are the same at some point. For example, their cost, procedure, duration, injuries, etc. In this blog, we will understand why we do a CT scan or an MRI, their uses, and which is better.
What is an MRI and What are they Used For?
An MRI takes three-dimensional images of structures in your body while using radio waves and magnets. The present molecules of the fat and water which is in your body, they align with the magnetic field and radio frequency. In the machine, the radio wave is fixed, which catches the problem and takes an image of your body. An MRI uses strong magnetic so extra precautions are necessary to ensure that you don’t have any metal in or on your body. This helps the doctor to see the body parts that don’t have bones like soft tissues and they use them to diagnose issues with:
- Brain
- Knees
- Nerves
- Spinal cord
- Shoulder
- Other joints
Doctors use an MRI rather than a CT scan if you are pregnant but require imaging. But they use it with proper care and when it is necessary, otherwise they don’t use it. It is also used to identify health conditions like:
- Brain
- Epilepsy
- Herniated discs
- Meningitis
- Multiple sclerosis
- Spine tumors
What is a CT Scan and What is It Used For?
A CT scan is done using an X-ray machine. It takes the details of cross sectional X-ray images and three dimensional image of your particular part of the body, when we combine and look together. It is quick but gives less detail than the MRI for soft tissues. A CT scan is used for:
- Emergencies like internal bleeding, bone fractures, bowel blockages, brain hemorrhage, or blood clots.
- Locating tumors in certain organs
- Monitoring the cancer which is spread to other areas of the body.
What to Expect During an MRI and a CT Scan?
There are a lot of things which we expect from the MRI and CT scans. So, let’s find out:
MRI Scan
At the start, when you are getting an MRI, you should tell your technician or your doctor that you have any implants like pacemakers or stimulators. You have to tell because MRI uses strong magnets and not all metals are compatible for use and for implantation; they use another type of magnet. It is a painless procedure, so you don’t have to worry about anything.
Before starting the test, they make you drink the solution or inject it into your vein. Then you have to change into the clothes which they provide like medical scrubs (top and pants) or a hospital gown. Mainly, an MRI takes 25 to 40 minutes to complete, but sometimes it takes 90 minutes. It depends on which body part require to takes the images and if it needs to retake the images.
During the procedure, you have to lie still and straight without any movement till you are told. Because if you move when the machine is taking the images, then it will be blurry and the technician has to take the photos again. A technician will tell you that how much time it will take to complete.
He will tell you when you can move or shift and when you have to hold your breath for some time. When the scan starts, it makes loud thumping noises which is not good for your ears to listen. So, the technician offers you the earplugs or headphones and plays your favourite songs.
CT Scan
In this, your doctor injected the contrast fluid inside your body and if it is digestive tract, then you have to drink that contrast. Put on the medical scrubs or a hospital gown and you have to lie down on the table during the CT scan. Then the table moves inside the CT machine which looks like a ring shap which is so large. It moves in a circular motion and scanner rotates around the patient, which sends the X-ray beam from different angles. It takes the cross sectional pictures of the inside of your body. This machine creates less volume than MRI machines and it also takes less time than an MRI. This machine takes the cross sectional images of a certain body part from different angles. The images are in 2D forms and then it send to a computer which they transform in 3D images.
CT Scan vs MRI: Key Differences
Here, you will know the difference between MRI and CT scans:
| Feature | MRI | CT Scan |
| Full Form | Magnetic Resonance Imaging | Computer Tomography |
| Technology | Radio Waves and Magnetic Field | X-rays and Computers |
| Radiation | No Radiation, No Ionising | Yes, Uses ionizing Radiation |
| Speed | 30 to 90 Minutes (Slow) but it can take 10 minutes with the help of AI tools | 10 to 15 Minutes (Fast) |
| Image Quality | Superior for Soft Tissues | Good for High Density |
| Cost | Most Expensive | Less Expensive |
| Use | Less uses | Common Uses |
| Best For Diagnostic Capabilities | Soft tissues, Brain, Joints, Nerves, Spinal Cord, Tumors, Vascular Disorder, Multiple Sclerosis, Neurological Conditions, Breast Cancer, | Bones, Lung Issues, Emergencies, Trauma, Cancer Staging, Brain Hemorrhage, Fractures, Tumors |
| Noise and Comfort | Noisier, Narrow Tube | Quieter, Faster |
| Contraindications | Metal Implant, Pacemaker | Allergies to Iodine Contrast |
| Contrast Agent | Gadolinium Based | Iodine Based |
| Emergency Application | Rarely use | Preferred as First Time |
Advantages and Disadvantages of MRI
There are a lot of advantages and disadvantages of an MRI, which you will get to know:
Advantages
- It produces more detailed images
- They don’t use radiation
- MRI images help to identify the issues.
- MRI produces a clear image.
Disadvantages
- It creates loud noises.
- Before the scan, you have to remove the jewellery, metal objects, and the clothes which contain metal.
- Medical and metal implants can interfere and can be harmful.
- Claustrophobic patients can feel uncomfortable in the machine.
- It is necessary for you to control your breathing during the procedure.
Advantages and Disadvantages of CT Scans
There are a lot of advantages and disadvantages of a CT scan, which you will get to know:
Advantages
- It is used in an emergency situation.
- A CT scan helps to identify the issues in the soft tissues.
- Only the affected part enters the machine, so you will not feel claustrophobic.
Disadvantages
- It involves a small dose of ionising radiation which can increase the small risk of developing cancer.
- This is not for pregnant women unless it is an emergency.
- A CT scan doesn’t provide clear and full details compared to an MRI.
Risks and Benefits of CT scan and MRI
There are so many risks and benefits for the CT scan and the MRI. So at first, we will know what the risks are:
CT Scan Risks
- It can harm the unborn babies.
- The ionizing radiation is based on which scan it is and how often this scan is used.
- Use of dyes can have a bad impact or reaction on the body.
MRI Scan Risks
- It can react to the metallic implant due to the magnetic field.
- Loud noise can cause hearing problems.
- May increase the body temperature.
- Anxiety and claustrophobia.
- Use of dyes can creat the compilation to the people who have kidney disease.
Benefits
- MRI and CT scans can see the internal body structures.
- A CT scan can provide pictures of tissues, organs and skeletal structures.
- An MRI scan pictures of abnormal tissues.
- MRI gives the details in the images.
CT Scan vs MRI: Which is Better for Conditions and Injuries?
There are a lot of conditions and injuries which is require in the CT scan or an MRI.
MRI
MRI is an expert in spotting the sports injuries and musculoskeletal conditions that include:
- Achilles tendon ruptures
- ACL injury
- Cartilage loss
- Joint inflammation
- Meniscal tears
- Nerve compression
- Rotator cuff tears
- Spinal injuries
- Sprains and strains
CT Scan
A CT scan is an expert in spotting:
- Bone fractures that are not visible on X-ray
- Blood clots
- Organ injuries
So, CT scan and MRI, both are not better. They are perfect and useful in their own way. They tell or picturise the things which other don’t.
How do Doctors Decide Which Scan to Use?
If the doctors are not sure of the condition or cause of your symptoms, then they suggest a CT scan. After the CT scan result, when the doctors are sure about the condition, they suggest the MRI test. So that they can see the infected part of the body in a clear way. Apart from this, your doctor mostly recommends that you get an MRI or a CT scan based on your symptoms. If the doctors need a more detailed image of your soft tissue, ligaments, or organs, then also they will suggest an MRI. If the doctor needs a normal image of an area like your internal organs, a fracture or head trauma, then a CT scan will be highly recommended.
It also depends on the patient and their particular type of cancer or breast conditions and everyone has their unique case. When the doctor wants to check a bony structure, a CT scan is a good option for that. But if they’re trying to distinguish between normal tissue and cancerous tissue, an MRI is a better choice. Rather than this, a CT scan is fast and it is used when doctors need to make quick decisions. An MRI is slow and it is used when doctors need to see in detail and deeply into the injury.
Conclusion
At the end of the blog, we hope that you understand the difference between an MRI and a CT scan. The procedure of MRI can take 30 to 90 minutes, but with new AI technology, some advanced technologies may reduce MRI scan time, but duration varies depending on the case. In an MRI you can’t move your body because it can create a blurred picture. However, in a CT scan you don’t have to face this problem because it takes less time, and many more. There are so many advantages and disadvantages, risks, and benefits of MRI and CT scans. At last, we come to the conclusion that neither MRI nor CT scans is better. In their own way, they are the best and most useful.
Note: You should go and see the doctor for any problems you are facing and they will suggest to you the CT or MRI scans according to your symptoms. This blog is for gaining the knowledge of MRI and CT scans.
