An MRI scan uses a strong magnet and radio waves, not X-rays, to create detailed pictures inside your body. Learn what it shows, how it works and how to prepare.
An MRI (Magnetic Resonance Imaging) scan is a painless test that uses a strong magnet and radio waves to take detailed pictures of organs, soft tissue, bones and nerves. It does not use X-rays or ionising radiation.
How Does an MRI Scan Work?
Your body contains a lot of water, and water has hydrogen atoms. Inside the MRI machine, a strong magnet lines up these atoms. Short bursts of radio waves then knock them out of line. When they return, they send signals that a computer turns into clear images. Different tissues send different signals, so the doctor can tell normal tissue from abnormal tissue.
Body areaCommon reasons for MRIWhat MRI shows wellBrain and spineHeadache, stroke, nerve pain, weaknessBrain tissue, spinal cord, discsJointsKnee, shoulder or hip pain after injuryLigaments, cartilage, tendonsAbdomen and pelvisLiver, uterus, prostate problemsSoft organs and massesHeart and vesselsHeart muscle disease, blood vessel problemsHeart structure and blood flowWhen Is an MRI Scan Advised?
- Unexplained headaches, dizziness or seizures. See MRI brain scan.
- Back pain with leg pain or numbness. See MRI for sciatica and slipped disc.
- Knee or shoulder injuries in sports or daily life.
- Checking tumours, cysts or unclear lumps found on ultrasound or CT.
- Looking at the prostate, uterus or ovaries in more detail.
- Planning surgery or checking treatment results.
MRI vs CT Scan: A Quick Comparison
MRI gives better detail of soft tissue and uses no radiation, but it takes longer. CT is faster and better for bones, lungs and emergencies. Your doctor picks the test that suits your problem. Read MRI vs CT scan for more.
How to Prepare for an MRI Scan
- Remove jewellery, watches, hearing aids, hair clips and belts.
- Tell the staff about a pacemaker, metal implant, cochlear implant, surgical clips or any metal fragments. See MRI safety with implants.
- Fasting for 4 to 6 hours may be needed for abdomen or pelvis scans.
- Tell the team if you are pregnant or have kidney disease, especially if contrast is planned.
- If you feel nervous in closed spaces, read MRI and claustrophobia tips.
Full details are in MRI scan preparation.
What Happens During the Scan?
You lie on a table that slides into a tunnel-shaped machine. The scanner makes loud knocking sounds, so you get earplugs or headphones. You must stay still. A scan usually takes 20 to 45 minutes, and some take up to an hour. You can talk to the technologist through an intercom. Learn the steps in MRI scan procedure and why MRI is noisy.
Is MRI With Contrast Needed?
Sometimes a contrast dye (gadolinium) is injected to make certain areas clearer, such as tumours or inflammation. Many scans are done without it. Your doctor decides. See MRI with contrast.
Getting Your MRI Report
A radiologist studies the images and writes a report, usually within 24 to 48 hours. Bring your old scans for comparison, because it helps the radiologist spot changes. See how to read your MRI report.
Practical Tips for a Smooth MRI
Arrive 15 minutes early so that the safety form can be filled calmly. Use the toilet before the scan, because lying still for 30 to 45 minutes is easier with an empty bladder. If you have a tattoo, dental implant or old surgery, mention it, since some metals can cause heating or blur the image. Wear comfortable clothes without zips. Bring your previous MRI, CT or ultrasound reports, as the radiologist compares them to see if a problem has grown, shrunk or stayed the same.
Frequently Asked Questions
What is an MRI scan used for?
It is used to see soft tissues, the brain, spine, joints, abdomen, pelvis and heart in great detail.
Is MRI harmful?
No. MRI does not use ionising radiation. It is considered safe when metal safety checks are followed.
Is MRI painful?
No. You only lie still. The loud noise is the main discomfort, and earplugs help.
How long does an MRI scan take?
Most scans take 20 to 45 minutes. Scans with contrast or many body parts may take longer.
Can I eat before an MRI?
For brain, spine and joint scans you can eat normally. Abdomen and pelvis scans may need 4 to 6 hours of fasting.
Who should not have an MRI?
People with some pacemakers, cochlear implants or metal in the eye may not be able to. Always inform the staff.
Is MRI safe in pregnancy?
MRI without contrast is generally considered safe when needed. See MRI during pregnancy.
What if I feel scared inside the machine?
Tell the technologist. You can use a call button, and the scan can be paused or calming steps can be used.
How much does an MRI cost?
Cost depends on the body part and whether contrast is used. See MRI scan cost factors in Delhi.
Book Your Test at Ganesh Diagnostic
Ganesh Diagnostic & Imaging Centre in Rohini, Delhi offers this test with trained radiology staff and clear reports. You can book an appointment online, check our branches across Delhi NCR, contact us for current rates, or explore all our services.
This article is for general information only. It does not replace advice from your doctor. Always follow your doctor's instructions for your test.
