Object ID: 00000018WIA30F10970GYZ
Topic ID: id_40023094 Version: 1.5
Date: May 4, 2022 1:42:41 AM

Wide bore systems cradle restrictions

The graphic prescription cannot always be acquired due to insufficient cradle scan range. The cradle cannot advance to isocenter if the landmark is less than 23 cm from the edge of the cradle. Below are two examples: feet first head prescription and a head first, lower leg prescription.

Wide bore systems with a stationary table considerations

For a lower leg scan with a head first position, there is a landmark limitation tick mark on the table that is 53.3 cm from the foot end of the table.

Figure 1. Blue line indicates landmark limitation

If the landmark is over the limitation tick mark, then a message may be posted indicating that the scan cradle could not go far enough into the bore to complete the scan.

Figure 2. An example of graphic Rx with patient head first and alignment light positioned at inferior edge of coil

Wide bore systems with a mobile table considerations

For a head scan with a feet first position, the alignment light is positioned at the extreme superior edge of the landmark position, which is approximately 23 cm from the edge of the cradle.

Figure 3. Alignment light at extreme superior edge of landmark position

If the graphic Rx slices are positioned at the superior end of the FOV, then a message may be posted indicating that the scan cradle could not go far enough into the bore to complete the scan.

Figure 4. Three examples of graphic Rx with patient feet first and alignment light positioned at superior edge of coil

Table 1. Image legend
Number	Description
1	Entire brain graphic prescription does not present a problem.
2	Orbit graphic prescription does not present a problem.
3	Scan prescription centered at the top of the head presents a problem and an error message is posted indicating that the scan table cannot go into the bore far enough to complete the requested prescription. Feet first positioning in this scenario cannot be completed.

For a lower leg scan with a head first position, the alignment light is positioned at the inferior edge of the landmark position, which is approximately 23 cm from the edge of the cradle.

Figure 5. Alignment light at extreme inferior edge of landmark position

If the graphic Rx slices are positioned at the inferior end of the FOV, then a message may be posted indicating that the scan cradle could not go far enough into the bore to complete the scan.

Figure 6. An example of graphic Rx with patient head first and alignment light positioned at inferior edge of coil