The primary difference between an MRI (Magnetic Resonance Imaging) and an EEG (Electroencephalogram) lies in what they measure and when they provide information.
MRI vs. EEG: A Detailed Comparison
| Feature | MRI (Magnetic Resonance Imaging) | EEG (Electroencephalogram) |
|---|---|---|
| What it Measures | Brain structure and tissue. | Brain electrical activity. |
| Timing | Provides a static "snapshot" at one point in time. | Monitors brain function in real-time. |
| Use Cases | Examining the brain's anatomy for abnormalities or damage. | Diagnosing and monitoring conditions like seizures, dementia, and epilepsy. |
| Information Provided | Structural information: size, shape, and any abnormalities. | Functional information: brain activity patterns and changes over time. |
Key Distinctions Explained
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MRI (Magnetic Resonance Imaging): This imaging technique uses strong magnetic fields and radio waves to create detailed images of the organs and tissues within the body. In the context of the brain, an MRI provides a static view of its structure. Thus, an MRI can only provide information about structures and tissues at one point in time.
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EEG (Electroencephalogram): An EEG is a non-invasive test that measures and records the electrical activity of the brain using small, metal discs (electrodes) attached to the scalp. Unlike an MRI, an EEG shows how the brain functions in real-time. An EEG is most often used when a doctor wants to see how the brain is functioning in real-time. This includes diagnosing and monitoring conditions such as seizures, dementia, or epilepsy.
Practical Applications
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MRI Examples:
- Detecting brain tumors.
- Identifying structural abnormalities after a stroke.
- Assessing damage from traumatic brain injury.
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EEG Examples:
- Monitoring brain activity during a seizure.
- Evaluating sleep disorders.
- Assessing brain function in patients with suspected dementia.
