A Brain MRI is one of the most informative tests in modern medicine. Unlike a CT scan, it uses no radiation. Unlike an EEG or a clinical neurological exam, it shows the brain itself in fine detail. In Guwahati, the most common reasons doctors order a Brain MRI are persistent headaches that have changed in character, suspected stroke, dizziness, head injury, and unexplained behaviour or memory changes.
Brain MRI vs CT scan: which one did your doctor ask for
A CT scan is fast and good at picking up bleeding, fractures, and large strokes. It uses X-rays, so it carries a small radiation dose. A Brain MRI is slower (25 to 45 minutes) but shows soft tissue in much more detail. It picks up small strokes, areas of inflammation, early tumours, and small bleeds that a CT can miss. If your doctor has written "MRI Brain" on the prescription, do not substitute it with a CT. Ask the doctor or the centre to confirm if you are unsure.
When a Brain MRI is the right test
Doctors in Guwahati typically refer for a Brain MRI in these situations: a headache that has changed pattern over weeks or is worse in the morning; sudden weakness or numbness on one side of the body; recent loss of vision in one eye; recurrent dizziness or balance problems; new seizures; suspected pituitary issues like vision changes with hormonal symptoms; head injury where symptoms persist after a normal CT scan; and follow-up of known conditions like a brain tumour or multiple sclerosis.
How to prepare
A plain Brain MRI needs no fasting and no special preparation. Wear comfortable clothes without metal zippers. Remove jewellery, hairpins, dentures, hearing aids, and any removable metal items. Tell the technician if you have a pacemaker, cochlear implant, surgical clips in the brain, an artificial heart valve, or metal in the body from previous injury or surgery. If your doctor has asked for a contrast scan, fast for 4 hours and bring a recent kidney function test.
What happens during the scan
You lie on a sliding table that moves into the scanner. The technician gives you earplugs because the machine is loud. The scan takes 25 to 45 minutes for a plain Brain MRI and 35 to 55 minutes if contrast is used. You must lie still during the scan. There is a panic button you can press if you feel uncomfortable. Some centres in Guwahati now offer wide-bore machines that are easier for claustrophobic patients.
Getting the report
Most centres in Guwahati deliver the signed Brain MRI report within 24 hours, often the same day. A typical report has three sections: technique, findings, and impression. The impression is the radiologist's summary. If you find medical terms confusing, take the report to your referring doctor for interpretation. Do not rely on internet searches for individual phrases, since context matters.
Common findings explained
Two findings frequently mentioned in Brain MRI reports cause unnecessary worry. The first is "small vessel ischaemic changes", which are tiny age-related changes in the deep white matter of the brain. They are very common after age 50 and usually do not need treatment by themselves. The second is "incidental cyst" or "small T2 hyperintensity", which often refers to a benign finding that does not affect daily life. Always discuss these findings with the doctor who knows your full clinical picture.