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Asset Type
Manufacturer
Model
What This Guide Helps With
Table motion, height, indexing, or alignment issues caused by obstruction, setup, power, interlock, or positioning faults.
Step-by-Step Troubleshooting
1. Ensure Patient Safety First
Do not troubleshoot table movement issues with a patient on the table unless movement is required for immediate patient safety.
Action:
- Stop the scan or setup process.
- Move the patient to another CT system or safe patient surface if table movement is unreliable.
- Confirm the table is not unexpectedly moving, lowering, or locked in an unsafe position.
Expected outcome: Patient is safe and the CT table is not being operated under unsafe conditions.
2. Verify the Reported Table Issue
Confirm exactly what the table is doing before deeper troubleshooting.
Action:
- Ask whether the issue involves vertical movement, horizontal movement, indexing accuracy, table alignment, docking, or table motion during scan setup.
- Observe whether the problem occurs from the gantry controls, operator console, table-side controls, or all controls.
- Note any displayed error messages, warnings, or interlock indicators.
Expected outcome: The failure mode is clearly identified instead of treated as a general table problem.
3. Check for Physical Obstruction Around the Table
External obstruction is one of the first things to rule out.
Action:
- Inspect around the table base, cradle, floor track area, side covers, foot end, and gantry opening.
- Remove linens, positioning aids, straps, cables, IV tubing, stools, trash cans, or other items that may restrict table travel.
- Confirm nothing is caught between the moving tabletop and fixed table structure.
Expected outcome: Table moves normally if the issue was caused by obstruction. If resolved, return the system to service after confirming normal movement and stop troubleshooting.
4. Check Emergency Stop and Safety Interlocks
A pressed emergency stop or active safety interlock can prevent table movement.
Action:
- Inspect all accessible emergency stop buttons at the gantry, console, and room locations.
- Reset any activated emergency stop according to site procedure.
- Check for open covers, panel interlocks, collision detection messages, or safety-related warnings.
Expected outcome: Table movement returns if a safety stop or interlock was active. If resolved, verify normal table motion before clinical use and stop troubleshooting.
5. Confirm CT System Power and Ready State
The table may not move if the scanner is not fully initialized or ready.
Action:
- Verify the CT system, gantry, operator console, and table are powered on.
- Confirm the system is not stuck in startup, shutdown, service mode, scan abort, or error recovery.
- Review console messages for table-related or gantry communication warnings.
Expected outcome: Table controls respond once the CT system reaches a normal ready state.
6. Test Table Movement From Multiple Control Points
This helps separate a local control issue from a larger table drive or system issue.
Action:
- Try table movement from the gantry/table controls.
- Try movement from the operator console if available.
- Compare vertical, horizontal, and indexing functions separately.
- Do not force movement or repeatedly command the table if it stalls, binds, or makes abnormal noise.
Expected outcome:
- If one control point fails but another works, suspect a local control, keypad, switch, or communication issue.
- If all control points fail, suspect a table drive, power, interlock, or system-level issue.
7. Inspect Table Accessories and Patient Positioning Devices
Incorrectly installed accessories can interfere with table travel or alignment.
Action:
- Check head holders, arm boards, body cradles, immobilization devices, extension boards, and positioning pads.
- Confirm accessories are fully seated and compatible with the table setup.
- Remove nonessential accessories and retest table movement if safe.
Expected outcome: Table movement or alignment returns to normal if an accessory was interfering with travel or positioning.
8. Check Table Load and Patient Positioning Conditions
Excessive load, uneven weight distribution, or positioning near travel limits can affect movement.
Action:
- Confirm the table is not overloaded beyond site-approved operating limits.
- Make sure weight is centered and the tabletop is not being side-loaded.
- If safe, return the table toward a neutral position and retest movement without unnecessary load.
Expected outcome: Table movement improves if the issue was related to loading, imbalance, or travel limit conditions.
9. Verify Table Position, Home, and Indexing Behavior
Alignment issues may be caused by the table not returning to a known position.
Action:
- Check whether the system recognizes table position correctly.
- Attempt normal table home, zero, or reset functions available to the operator workflow.
- Compare indicated table position with the actual physical position.
- Watch for inconsistent indexing, incorrect displayed position, or failure to stop at expected locations.
Expected outcome:
- If the table position corrects after normal reset/home operation, verify accuracy before returning to use.
- If displayed position does not match actual movement, remove the scanner from service.
10. Check for Gantry-to-Table Alignment Problems
Poor alignment can affect patient centering, scan setup, and image accuracy.
Action:
- Inspect table alignment relative to the gantry opening and laser positioning references.
- Confirm the tabletop is not visibly skewed, shifted, loose, or misaligned.
- Verify the table docks or aligns normally with the scan plane.
- Do not perform patient scanning if table position accuracy is questionable.
Expected outcome: Table alignment appears stable and consistent. If alignment is visibly off or inconsistent, escalate for service evaluation.
11. Listen for Abnormal Mechanical Sounds
Noise can indicate mechanical binding, drive strain, worn components, or obstruction.
Action:
- Operate the table only briefly and safely.
- Listen for grinding, clicking, slipping, squealing, banging, or motor strain.
- Stop testing immediately if movement is jerky, uneven, or worsening.
Expected outcome:
- Smooth, quiet movement suggests the issue may have been external or intermittent.
- Abnormal sound with movement suggests mechanical or drive-related failure requiring repair.
12. Perform a Controlled System Restart Only If Safe
A software or communication fault may temporarily prevent table control.
Action:
- Confirm no patient is on the table.
- Follow site procedure to restart the CT system.
- After restart, verify table movement, position readback, alignment, and console status.
- Do not restart during an active clinical emergency unless directed by site protocol.
Expected outcome: Table movement returns if the issue was a temporary software or communication fault. If resolved, perform functional checks before clinical use and stop troubleshooting.
If the Problem Persists
If table movement or alignment issues continue after checking obstruction, emergency stops, interlocks, power state, accessories, load conditions, controls, and basic reset behavior, common external causes have been ruled out.
The issue may involve the table drive, position sensors, encoder feedback, control electronics, communication path, alignment hardware, or internal calibration. The CT scanner should be:
- Removed from service
- Labeled Out of Service
- Sent for repair, vendor service, or bench/system evaluation
Knowing when to stop is proper troubleshooting. Do not continue scanning if table motion or position accuracy is unreliable.
Clinical Use Tip
Do not troubleshoot table movement problems while a patient is on the table unless the action is needed to safely remove the patient. A table that moves unpredictably, fails to stop correctly, or reports incorrect position can create patient safety and image accuracy risks. Move the patient to a backup device or safe patient surface first so therapy continuity and patient care are maintained.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"CT staff reported the Canon Aquilion table would not move horizontally during patient setup and the table position did not appear to match the console display."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found no external obstruction, emergency stop activation, accessory interference, or power issue, but table indexing remained inconsistent after restart."
Resolution
What action was taken.
Example:
"Scanner was removed from service, labeled Out of Service, and escalated to CT service/vendor support for table motion and position feedback evaluation."
Helpful Details to Include (If Known)
- Whether the issue involved vertical, horizontal, or indexing movement
- Whether the table failed from gantry controls, console controls, or both
- Any table, gantry, or interlock messages displayed
- Emergency stop status
- Whether physical obstruction was found
- Accessories installed during the failure
- Patient load or positioning conditions
- Unusual sounds during table movement
- Whether the table position display matched actual table position
- Whether restart or home/reset restored function
- Final device status
Final Thought
CT table issues should be handled carefully because table position directly affects patient safety, scan setup, and image accuracy. Start with visible and external causes first, verify whether the problem is control-related or mechanical, and escalate when movement or alignment cannot be trusted. Clear CCR documentation helps show what was checked and why the scanner was removed from service.
That is successful troubleshooting.