Many people think that MRI ( Magnetic Resonance Imaging ) and CT Scan ( Computed Tomography ) are the same examination because both are used to see the condition of internal organs. In fact, both have significant differences, both in terms of how they work, their functions, and the imaging results produced. What are the differences between the two?
What is CT Scan and MRI?
CT Scan ( Computed Tomography Scan ) is a medical examination that uses X-rays and computer technology to produce detailed images of structures inside the body, such as bones, organs, and blood vessels. This process works by taking pictures from different angles and combining them into a three-dimensional image. CT Scans are usually used to detect injuries, tumors, internal bleeding, or problems with certain organs, such as the lungs and liver.
While MRI ( Magnetic Resonance Imaging ) is an imaging technique that uses a strong magnetic field and radio waves to produce detailed images of soft tissues, such as the brain, nerves, muscles, and ligaments. Unlike CT Scan, MRI does not use radiation so it is safer for long-term examination. MRI is often used to detect disorders of the brain, spinal cord, joints, and diseases of internal organs such as the heart and liver.
Difference Between CT Scan and MRI
Although often considered the same, CT Scan and MRI are actually two different things. Here are the differences:
1. Working Principle
CT scans use X-rays to take pictures of the body from multiple angles, while MRIs use magnetic fields and radio waves to produce more detailed images of soft tissue.
2. Type of Network Analyzed
CT scans are better at detecting abnormalities in bones, lungs, and internal organs with fast, clear images. Meanwhile, MRI is superior in showing details of soft tissues such as the brain, nerves, muscles, and ligaments.
3. Examination Time
CT scans are usually quicker, taking only a few minutes to produce images, while MRIs can take longer, around 30 to 60 minutes, depending on the area being examined.
4. Radiation
CT Scan uses X-rays that contain ionizing radiation, so it is not recommended for repeated examinations. In contrast, MRI does not use radiation, so it is safer for patients, especially for long-term examinations.
5. Patient Comfort
When undergoing an MRI, patients must lie in a narrow room with quite noisy machine sounds, which can cause discomfort, especially for those with claustrophobia. CT Scan is more open and less claustrophobic for patients.
6. Costs
MRI is generally more expensive than CT Scan because the technology used is more complex and requires a longer examination time.
Get to Know the Functions of CT Scan and MRI
CT Scan and MRI are two medical imaging methods that doctors use to see the condition of the body's internal organs without the need for surgery. Although both provide images of the inside of the body, their functions are slightly different.
1. CT Scan Function
- Detecting bone injuries and fractures.
- Diagnosing tumors, cancer, and their spread.
- Examining internal organs such as the lungs, liver and kidneys.
- Detecting internal bleeding or stroke.
- Assisting in guiding medical procedures, such as biopsies.
2. MRI function
- Analyzing the brain and spinal cord (e.g. stroke, tumor, or multiple sclerosis ).
- Evaluate the condition of joints, muscles and ligaments, especially for sports injuries.
- Diagnosing problems with the heart and blood vessels.
- Examine internal organs such as the liver, kidneys, or uterus in high detail.
- Detecting nerve and other soft tissue disorders.
Preparation Before CT Scan and MRI
Before undergoing a CT Scan or MRI, there are several preparations that need to be made so that the scanning process runs smoothly and the results are more accurate.
Preparation Before CT Scan:
- Patients may be asked to fast for 4–6 hours before the examination.
- Avoid jewelry and metal accessories such as necklaces, earrings, or metal buttons must be removed because they can interfere with the imaging results.
- Inform your doctor about your health condition.
- Wear special hospital clothing for comfort during the examination.
Preparation Before MRI:
- MRI uses a strong magnetic field, so jewelry, watches, credit cards, or electronic devices must be removed.
- Inform your doctor if you have any metal implants such as pacemakers, joint implants, or metal objects in your body because they may affect the examination.
- Some MRI examinations, especially those using contrast, may require the patient to fast for several hours.
- If you feel anxious about being in a confined space, your doctor may give you a mild sedative before the procedure.
- As with CT scans, patients may be asked to wear special clothing to avoid interference from certain materials in regular clothing.
Before undergoing an examination, discuss it first with your doctor to get directions that suit your health condition.
Which is Better Between CT Scan and MRI?
Both CT Scan and MRI have their own advantages, depending on the medical condition being examined. CT Scan is better for detecting bone abnormalities, accident injuries, internal bleeding, and lung and other internal organ diseases because the process is fast and the results are clear. Meanwhile, MRI is superior in showing details of soft tissues, such as the brain, nerves, muscles, and ligaments, making it more suitable for diagnosing nerve disorders, joint injuries, or complex internal diseases. In addition, MRI is safer because it does not use radiation but the examination takes longer and costs more than CT Scan.
To ensure the right choice according to your health condition, you should consult a doctor first. The doctor will help determine the type of examination that best suits your medical needs so that the results are more optimal and accurate.
Article written by dr. Ardra Christian Tana, Sp.Rad (Radiology Specialist Doctor, EMC Alam Sutera Hospital).