GE CT-9800

GE MEDICAL SYSTEMS CT 9800 QUICK SYSTEM
Rev. 12 Direction 18000
6-9A-23
9A-8 HiLight CBF Alignment (Requires a cold tube)
This procedure aligns the center of the body filter coincident with ISO alignment.
Refer to Illustration 6-9A-14 for the procedure flow.
NOTE: Verify that the Tube Unit is “cold”; i.e., that it has had no more than 25 kilojoules exposure
[KV•mA•Sec/1000] within the last 30 minutes. Wait a minimum of 90 minutes from the completion of
a generator cal or other high technic exposures. Each exposure in this procedure adds 12.8kj of heat
to the tube, exposures should be made no faster than one every 5 minutes. Tube warm-up is not
recommended prior to this procedure.
1. Use the calibration scan ISOCAL from Section 9A-6, Step 1.
2. Generate a CBF scan. This should be CTDS default scan #7; “CBF SCAN”.
Enter CTDS
• (DC) Data Collection
• (9 ) Select Default
• (7 ) Default #7; ”CBF SCAN”
• (N) Cal phantom type
• (N) Reduced F.O.V.
• (1) Number of Scans
• (CBF) Enter run description
• (CR) Enter to proceed
Perform the scan and record the exam number.
3. Enter alignment program in CTDS
Enter CTDS
• (AL) Alignment
• (2) Center Body Filter
• (xx) Select Exam # recorded in step 2.
• (yy) Enter ISOCAL for calibration filename
• (zz) Enter value of ISOCENTER from Section 9A-6.
The program will calculate CBF and display it along with recommendations for moving the collimator
if
CBF is outside specifications. Exit the Alignment program.