Magnetic Resonance Imaging (MRI)
A single solution for all the production measurement needs
Metrolab’s Magnetic Field Camera is the only instrument able to cover nearly all the magnetic measurement needs of MRI magnet production.
MRI – Production
High precisionPrecision is how closely multiple measurements will be clustered. Also called reproducibility or repeatability. In everyday speech, often confused with... More magnetic measurements in a factory environment represent a tremendous challenge, as even the distant passing of large iron objects such as an overhead crane or a fork-lift cause major field distortions. Only rapid, precise and reliable measurements allow technicians to recognize and avoid such spurious effects.
Mapping and shimming: over 1000 points in a few minutes!
MRI magnets use iron shims and shim coils to compensate for field inhomogeneities. An accurate field map is crucial to compute the exact compensation required. After shimmingIn magnet production, the process of making a magnetic field more homogeneous, by placing pieces of iron (shims) in the... More, the field is remapped to verify the results, and, if needed, the entire process is repeated.
Using a single-point teslameterSee magnetometer. More, shimmingIn magnet production, the process of making a magnetic field more homogeneous, by placing pieces of iron (shims) in the... More is extremely tedious at best. At worst, it will never converge. The Magnetic Field Camera simultaneously measures up to 32 points, and is now standardA standard is the internationally agreed-upon physical representation of a unit. For example, a caesium clock is the standard for... More equipment for nearly all the world’s MRI magnet manufacturers.
Ramping: exactly at the specified field!
When a superconducting magnetAn electromagnet built with superconducting wire. To remain superconducting, the coil has to be maintained at cryogenic temperatures, so it... More is first “turned on,” current is injected until the specified field has been attained. The power supply can then be removed, and the field is maintained by the current that continues to circulate in the superconducting coils. The Magnetic Field Camera allows this point to be determined with great precisionPrecision is how closely multiple measurements will be clustered. Also called reproducibility or repeatability. In everyday speech, often confused with... More.
Decay monitoring: when the field is stable – no sooner, no later!
Due to small shifts of the conductors in the strong magnetic field, a new superconducting magnetAn electromagnet built with superconducting wire. To remain superconducting, the coil has to be maintained at cryogenic temperatures, so it... More needs time to “settle down.” The extreme resolutionResolution measures the ability of a magnetometer to distinguish ("resolve") two nearly identical field values. Related to precision, but not to... More and stability of the Magnetic Field Camera allows this very slight decayFor superconducting magnets, decay refers to the infinitesimally small and slow loss of current and corresponding decrease in magnetic field.... More to be observed in real time. Further measurements can be performed only when the field is stable – sooner would invalidate the measurements, and later unnecessarily prolongs the production time.
A full complement of tools
For situations where the field needs to be monitored over a wide rangeThe range of a probe is defined by the minimum and maximum field strength it can measure. On an instrument,... More, or if several magnets need to be monitored at the same time, Metrolab recommends the use of one of its single-point NMRNuclear Magnetic Resonance. A resonance phenomenon seen when you irradiate a sample in a magnetic field with an RF field.... More teslameters. For quick trouble-shooting, inside and outside the boreThe centre of a solenoidal magnet, where the magnetic field is concentrated. More, Metrolab’s hand-held three-axisThe magnetic field is a three-dimensional vector quantity. A single Hall element only measures one component. A three-axis Hall instrument has... More magnetometerAn instrument to measure magnetic flux density (B) or magnetic field intensity (H). More is the perfect companion for the high-precision NMRNuclear Magnetic Resonance. A resonance phenomenon seen when you irradiate a sample in a magnetic field with an RF field.... More systems.