Final Table-Gantry Alignment - GE CT-9800 Technical Publications

GE MEDICAL SYSTEMS
Rev. 1
16. Press the MOVE TO SCAN button, until movement stops.
17. Check that the phantom has advanced 31 cm and that the internal reference planes coincide with the
marks made on the phantom ± 1.5mm Axial, ± 3mm Sagital and Coronal.
Tilt the gantry ± 20
18.
19. Switch the alignment lights OFF.
20 Should any out of tolerance occur, refer to System Chapter 6 for adjustments.
9-3 Final Table Gantry Alignment
This procedure assumes alignment lights are aligned. Verify that the correct table to gantry alignment is correct
as follows.
Center the 35 cm poly phantom using standard system software to ± 0.25mm.
1.
2. Press the LIGHTS button on the table, verify the alignment lights are ON.
3. Verify that the sagittal and coronal beam are coincident with the center lines on the phantom.
4. Mark the intersections of the internal axial with sagittal and coronal beams on the edge of the phantom.
5. Move the phantom out of the gantry 31cm.
6. Verify that the intersection of the beams do coincide with the marks on the phantom.
The accuracy requirements are:
Internal and external axial
Sagittal and coronal
°
ensure axial beam does not walk along the coronal beam.
± 1.5mm
± 3mm
4-9-2
CT 9800 QUICK SYSTEM
Direction 18000