Magnetic Resonance Imaging
MRI uses powerful magnets and radio waves to produce detailed images of organs and soft tissues. Excellent for brain, spine, and joint imaging.
What is MRI?
MRI (Magnetic Resonance Imaging) is a non-invasive imaging technique that uses powerful magnetic fields and radio waves to create detailed images of organs and tissues. Unlike CT scans, MRI does not use ionizing radiation, making it safer for repeated imaging.
How it works: Your body is placed in a strong magnetic field which aligns hydrogen atoms in your tissues. Radio waves then disrupt this alignment, and as the atoms realign, they emit signals that are captured and processed into detailed images.
Common Uses of MRI
Brain and spinal cord imaging
Detect tumors, strokes, multiple sclerosis, and spinal disorders
Joint and musculoskeletal assessment
Evaluate torn ligaments, cartilage damage, and joint abnormalities
Cardiac imaging
Assess heart structure, function, and blood flow
Abdominal organ evaluation
Examine liver, kidneys, pancreas, and other abdominal organs
Breast cancer screening
Supplement mammography for high-risk patients
Sports and orthopedic injuries
Assess ACL, meniscus, and rotator cuff tears
Demyelinating and vascular brain disease
Characterize white matter lesions, aneurysms, and plaques
Advantages
- ✓No ionizing radiation exposure
- ✓Superior soft tissue contrast compared to CT
- ✓Can image in multiple planes without repositioning
- ✓Excellent for detecting subtle tissue changes
Limitations
- ⚠Longer scanning time compared to CT
- ⚠Loud noise during the procedure
- ⚠Not suitable for patients with certain metal implants or pacemakers
- ⚠Can cause claustrophobia due to enclosed space
- ⚠More expensive than CT or X-ray
Preparation & What to Expect
Before the Exam
Remove all metal objects including jewelry, watches, and hairpins. Inform your doctor if you have any metal implants, pacemakers, or claustrophobia. You may be given earplugs or headphones to reduce noise.
During the Exam
Remain as still as possible during the scan, which may last 15-90 minutes depending on the area being examined. You will hear loud knocking or thumping sounds.
After the Exam
You can usually resume normal activities immediately unless you were given a sedative for anxiety or claustrophobia.
Related Imaging Methods
For faster imaging or bone detail, consider CT. For real-time imaging without radiation, ultrasound is an option. Functional MRI (fMRI) can show brain activity.
CT
CT scans use X-rays to create detailed cross-sectional images of the body. They are particularly useful for detecting bone fractures, tumors, and internal bleeding.
Ultrasound
Ultrasound uses sound waves to create real-time images. Commonly used for pregnancy monitoring and examining organs like the heart, liver, and kidneys.
Browse MRI Terms
Explore common findings and terminology in MRI reports. Each term includes detailed explanations, clinical significance, and related lab tests to help you understand your imaging results. lab tests.
ACL Tear
Discontinuous or lax low-signal ACL fibers with abnormal orientation; bone contusions at lateral femoral condyle and posterolateral tibia.
Avascular Necrosis of the Femoral Head
Subchondral serpiginous low-signal rim with inner high-signal on T2 (double-line sign); marrow edema early.
Cerebral Aneurysm
Round or saccular outpouching from cerebral artery, typically at vessel bifurcations
Herniated Disc (Disc Herniation)
Disc material protruding beyond normal disc space margins
Lumbar Spinal Stenosis
Narrowed central canal with crowding of cauda equina; hypertrophic ligamentum flavum and facet arthropathy common.
Meniscus Tear
Linear high-signal cleft reaching articular surface within meniscus; displaced fragments may form a bucket-handle.
Multiple Sclerosis Plaques
Ovoid T2/FLAIR hyperintense lesions oriented perpendicular to ventricles; Dawson’s fingers; active plaques enhance with gadolinium.
Pituitary Adenoma
Iso- to hypointense sellar mass on T1 with variable enhancement; may expand sella or invade cavernous sinus.
Rotator Cuff Tear
Discontinuity or retraction of supraspinatus/infraspinatus tendon with fluid signal in defect; muscle atrophy or fatty change may be present.
White Matter Hyperintensities (WMH)
Bright areas in brain white matter on T2/FLAIR sequences
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