What does Tesla actually mean?
Tesla (T) is the unit of magnetic field strength. A 3.0T MRI scanner produces a magnetic field twice as strong as a 1.5T scanner. In practice, higher field strength gives a better signal-to-noise ratio, which can be spent either on sharper images or on a shorter scan time.
Why field strength matters for preventive imaging
- Small lesions — findings in the liver, pancreas and prostate are often easier to characterise at 3T.
- Brain — subtle white matter changes and microbleeds may become visible earlier at 3T.
- Scan time — a full body protocol typically takes 45 to 60 minutes at 3T, and up to 90 minutes at 1.5T.
When is 1.5T enough?
For many standard orthopaedic questions, such as the knee or shoulder, 1.5T is perfectly adequate. It can also be the better option for patients with certain implants, because more devices are tested and approved at that field strength.
Field strength is only one factor. Coil technology, the protocol chosen and the experience of the reporting radiologist matter just as much for the quality of your result.