The RF sub system is the source of MRI proton excitation energy,
its efficiency directly affects the MRI relax signal. RF receiver
receive MRI relax signal, a good receiving coil can improve the SNR
of image.
The RF sub system is similar as highway lane, the more lanes, the
faster flow of vehicles. Vice versa, the more the RF system
channels, the faster parallel acquisition, thus the system can
process the greater the amount of data in the same time, reduce the
imaging time. Bstar-150 suing 8 / 16 channel radio frequency
receiving, combined with the latest parallel sampling technology,
using the DDC digital direct sampling, can short the scan time and
get excellent image quality.
Gradient sub system
Gradient sub system directly determines the spatial encoding of MRI
system, it produces the signal information, at the same time it can
perform GR series sequence scanning, it is the foundation of MRI
system’s spatial resolution ability, gradient sub system also
directly affect the scanning image thin slice scanning.
The linearity of gradient system of MRI system determine the
accuracy of spatial location information, ensuring that in any
acquisition, the image distortion is limited.
Gradient switching rate is an important factor of MRI scanning
speed. Bstar-150 using the self-shielding gradient coil and high
duty cycle gradient amplifier system, together with eddy
elimination technology and design, can avoid the eddy current
between the metal shielding layers, raise up the spatial encoding
ability of the magnetic resonance signal and make the scan more
precise, ensure high resolution image quality.
During superconducting MRI scans, the noise is much bigger than
permanent MRI systems, and staying in a closed environment, the
patient is easy to fall into tension. Bstar-150’s gradient sub
system adopts special hardware noise reduction design technology,
the gradient noise is reduced to 2/3, provide patients with
friendly scanning environment.
The gradient system is equipped with automatic detection function,
if the temperature is too high, the system can intelligently stop
the scanning, to protection of hardware from being damaged.
The system use water chiller to produce a stable running condition.
Comparison between Helium free 1.5T magnet and Traditional 1.5T magnet
| | BASDA Helium free 1.5T magnet | Traditional 1.5T magnet |
| Magnet character |
| 1 | Year launched in market | 2020 | before 2000 |
| 2 | Helium capacity | 0 | 800-2000L |
| 3 | Cooling method | Coils connect to cold head directly, no helium | Coils merge in liquid helium |
| 4 | Min. shielding room height | 2500mm | >2900mm |
| 5 | Magnet service tower | Highly integrated | Discrete |
| 6 | Inner pressure after quench | Normal pressure | Very high pressure(danger) |
| 7 | Restore from quench | <2.5 days, automatic | >10 days, site engineer necessary |
| 8 | Maintenance cost | Lose 0 liquid helium when quench | Lose ALL(800L-2000L) liquid helium when quench |
| 9 | Cost after quench | 0 dollar | 125,000 dollar |
| 10 | Local helium supplier | No need | Necessary |
| 11 | Liquid helium refill period | Never | Need refill in around 3-5 years |
| 12 | Magnet control | Inteligent "One touch" | Operator can not control |
| 13 | User experience | Relax | Always worry for power cut and liquid helium |
| 14 | Magnet transportation | All ways(by sea or land or air) | By sea or land only |
| System performance |
| 15 | Power consumption | 45kW | 50-75kW |
| 16 | Field Strength | 1.5T | 1.5T |
| 17 | Shielding Method | Active | Active |
| 18 | Shimming Method and Type | Active + Passive + Dynamic | Active + Passive + Dynamic |
| 19 | Magnet stability | ≤0.1ppm/h | 0.1ppm/h-0.5ppm/h |
| 20 | Homogeneity (10cm DSV, VRMS) | ≤0.01ppm | 0.01ppm-0.05ppm |
| 21 | Length of magnet(exclude cover) | 157cm | 140cm-1750cm |
| 22 | Inner diameter of magnet | 600mm | 600mm-700mm |
| 23 | 5 Gauss fringe field(X,Y,Z axis) | ≤2.5m x 2.5m x 4.0m | Around 3m x 3m x 4.5m |
| 24 | Self shielding design | Yes | Yes |
