A knee MRI scan uses strong magnets and radio waves to create detailed images of the inside of your knee without using radiation.
Here's a breakdown of how it works:
- Magnetic Field: You lie inside a large, cylindrical MRI machine that contains powerful magnets. These magnets create a strong magnetic field around your knee.
- Radio Waves: Radio waves are then emitted from the machine. These waves interact with the hydrogen atoms in the water molecules within your knee's tissues (bones, cartilage, ligaments, tendons, and muscles).
- Signal Detection: The hydrogen atoms respond to the radio waves by emitting their own signals. These signals are detected by the MRI machine's sensors.
- Computer Processing: The MRI machine's computer processes these signals to create cross-sectional images, or "slices," of your knee. These slices can be viewed individually or combined to create a 3D image.
- Image Interpretation: A radiologist then interprets these images to diagnose any injuries, diseases, or other conditions affecting the knee joint.
Key Aspects:
- No Radiation: Unlike X-rays or CT scans, MRI uses magnetic fields and radio waves, so there's no exposure to ionizing radiation.
- Detailed Images: MRI provides excellent detail of soft tissues like ligaments and cartilage, making it very effective for diagnosing knee injuries.
- Multiple Planes: Images can be taken in different planes (axial, sagittal, coronal) to provide a comprehensive view of the knee.
Why is this useful?
Knee scans are used to diagnose a wide range of knee problems, including:
- Ligament tears (e.g., ACL, MCL)
- Meniscus tears
- Cartilage damage
- Arthritis
- Bone fractures
- Infections
- Tumors
In summary, a knee MRI scan uses magnetic fields and radio waves to generate detailed images of the knee joint, allowing doctors to diagnose various conditions without the use of radiation.
