• Object ID: 00000018WIA30D20870GYZ
  • Topic ID: id_40026932 Version: 1.3
  • Date: Nov 23, 2021 11:33:00 AM

Field strength and bore comparisons

For an example of 1.5T spatial gradient see Figure 1.

For an example of 3.0T spatial gradient see Figure 2.

Since the main magnetic field doubles between 1.5T and 3.0T, the spatial gradient of the field will approximately double, given similar magnet designs.

Therefore, the SG exposure approximately doubles for 3.0T compared to 1.5T, for similar locations within the bore.

60 versus 70 cm

Since the magnet designs are similar for 60 cm and 70 cm scanners, the spatial gradient is similar at most locations, relative to the center of the magnet. However, a 70 cm system has a larger bore, and can reach higher SG contours. Therefore, the SG near the bore walls of a 70 cm system are higher than those for a 60 cm system.

This difference is approximately 20%.

Figure 1. Spatial gradients for a 1.5T magnet
Table 1. Image legend
NumberDescription
1Spatial gradient (G/cm) (blue lines)
2Bore wall (bold green lines)
3Area inside enclosures
Figure 2. Spatial gradients for a 3.0T magnet
Table 2. Image legend
NumberDescription
1Spatial gradient (G/cm) (blue lines)
2Bore wall (bold green lines)
3Area inside enclosures