Tesla
Unit of magnetic field strength. 1 T = 10,000 Gauss. Named for Nikola Tesla. Clinical MRI field strengths span:
- 0.2–0.3T — dedicated extremity / open low-field (Esaote O-scan, Hitachi Airis II).
- 0.55T — recent low-field re-emergence (Siemens MAGNETOM Free.Max).
- 1.2T — premium open (Hitachi Oasis).
- 1.5T — workhorse clinical standard (Aera, Symphony, Ingenia 1.5T, Signa Voyager).
- 3T — premium clinical (Prisma, Vida, Ingenia 3T, Signa Premier).
- 5T — recent commercial (UIH uMR Jupiter).
- 7T — research / FDA-cleared specialty.
Why it matters to buyers: Field strength drives image quality and scan speed. Higher field = better signal-to-noise per unit time, finer spatial resolution, and stronger advanced applications (DTI, fMRI, MR spectroscopy). Trade-offs: more artifacts (susceptibility, B1 inhomogeneity, chemical shift), higher cost, larger 5-gauss footprint, and stricter implant-compatibility constraints. 3T is mandatory for serious advanced neuro / cardiac / prostate work; 1.5T is sufficient for the bulk of routine imaging.
Why it matters to engineers: Magnet specs (field strength, bore size, homogeneity, ramp current) are the physical foundation everything else builds on. Helium boil-off, cold-head service interval, and quench risk scale with field strength on conventional superconducting magnets. Sealed-bore / zero-boil-off magnets at 1.5T are now broadly deployed; 3T sealed-bore is becoming standard.