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Manufacturer
Model
What This Guide Helps With
Table movement, height, cradle, or positioning errors caused by obstructions, controls, accessories, power, or mechanical table issues.
Step-by-Step Troubleshooting
1. Ensure Patient Safety First
Stop scanning immediately if table movement is abnormal, delayed, noisy, or uncontrolled.
Action:
- Remove the patient from the table if it is safe to do so.
- Use proper patient transfer assistance if the table cannot move normally.
- Do not continue scanning until table motion is verified.
Expected outcome: Patient is safe and not dependent on a questionable table movement system.
2. Verify the Reported Table Problem
Confirm exactly what motion is failing.
Action:
- Identify whether the issue involves table up/down movement.
- Identify whether the issue involves cradle in/out movement.
- Identify whether the issue involves table not indexing.
- Identify whether the issue involves table not moving to scan position.
- Identify whether the issue involves incorrect displayed table position.
- Identify whether the issue involves the table stopping mid-travel.
- Identify whether the issue involves a positioning error at the console.
- Identify whether the issue involves a gantry/table interlock message.
Expected outcome: The failure mode is clearly identified before troubleshooting continues.
3. Check for Physical Obstructions
External obstructions are a common cause of table movement errors.
Action:
- Inspect around the table base, cradle, gantry opening, floor area, patient accessories, straps, sheets, cables, IV lines, and positioning aids.
- Verify nothing is caught under the table, between the table and gantry, or along the cradle travel path.
Expected outcome: Table path is clear.
If an obstruction is found, remove it, retest table movement, and stop if the issue is resolved.
4. Confirm the Emergency Stop Is Not Activated
A pressed emergency stop can prevent table or gantry motion.
Action:
- Check all accessible emergency stop buttons near the scanner, gantry, operator area, and table area.
- Reset only if the area is safe and site procedure allows.
Expected outcome: Emergency stop circuit is reset and table movement is restored if that was the cause.
5. Check Table Controls at the Gantry
Determine whether the issue is isolated to one control point.
Action:
- Test table movement using the gantry/table control panel.
- Check if buttons respond normally.
- Look for stuck, damaged, or contaminated buttons.
Expected outcome: Table responds correctly from local controls.
If local controls work but console controls do not, the issue may involve console command, communication, or software control rather than the table drive itself.
6. Check Console Table Commands
Verify whether the table responds from the operator console.
Action:
- Attempt normal table positioning from the console.
- Observe if the command is ignored, delayed, or generates an error message.
- Compare console position display with actual table location.
Expected outcome: Console commands and actual table movement agree.
If the table moves locally but not from the console, document the difference and escalate for service evaluation.
7. Verify Patient Load and Table Setup
Excessive weight, uneven loading, or improper setup can affect table movement.
Action:
- Confirm the patient and accessories are within the site-approved table weight limit.
- Check that the patient is centered and not creating excessive side load.
- Remove unnecessary accessories or positioning devices if safe.
Expected outcome: Table is not overloaded or mechanically restricted.
8. Inspect Table Accessories and Cradle Interface
Improperly seated accessories may interfere with travel or positioning.
Action:
- Check head holders, pads, extension boards, straps, immobilization devices, and tabletop attachments.
- Verify accessories are fully seated, locked, and not extending into the gantry or travel path.
Expected outcome: Accessories are installed correctly and do not interfere with motion.
9. Listen for Abnormal Mechanical Sounds
Noise can help separate obstruction issues from mechanical drive problems.
Action:
- With no patient on the table, attempt limited table movement if safe.
- Listen for grinding, clicking, slipping, binding, or motor strain.
- Stop testing immediately if movement sounds abnormal.
Expected outcome: Table movement is smooth and controlled.
If abnormal noise is present, remove the scanner from service and escalate. Do not repeatedly cycle the table.
10. Check Table Position Display and Alignment Behavior
Positioning errors may occur when the system cannot confirm table location.
Action:
- Observe whether the displayed table position changes when the table moves.
- Check if the system reports position mismatch, table not ready, or unable to reach scan position.
- Verify the table returns to expected home or scan position when commanded.
Expected outcome: Displayed position matches actual table movement.
If actual movement and displayed position do not match, suspect encoder, sensor, calibration, or table control issues requiring service.
11. Perform a Safe System Reset
A software or communication fault may temporarily affect table positioning.
Action:
- Remove the patient.
- Follow site-approved CT shutdown and restart procedure.
- Allow the scanner, console, and table control system to restart fully.
- Retest table motion without a patient.
Expected outcome: Table movement returns to normal if the issue was a temporary control fault.
If the issue returns, continue escalation.
12. Verify Environmental or Floor Conditions
Floor obstruction or table base interference can cause movement problems.
Action:
- Inspect for floor damage, debris, loose covers, fluid, or items near the table base.
- Confirm nothing is contacting the table pedestal or restricting vertical travel.
Expected outcome: Table base and floor area are clean, dry, and unobstructed.
13. Check for Repeated Positioning Error During Scanning
Determine whether the table only fails during scan setup or indexing.
Action:
- Run only site-approved non-patient movement checks.
- Observe whether the table reaches scout, scan, or index positions correctly.
- Note whether the error occurs before scan, during table indexing, or after scan completion.
Expected outcome: Error timing is documented clearly for service.
If the table cannot reliably position for scanning, do not return the scanner to clinical use.
If the Problem Persists
If the table still does not move correctly, stops unexpectedly, reports position errors, or displays incorrect table location after external checks, common user-accessible causes have been ruled out.
The issue may involve the table drive assembly, motor control system, position encoder, limit sensors, interlock circuit, cabling, calibration, or internal control electronics.
The CT scanner should be:
- Removed from service
- Labeled Out of Service
- Reported to the imaging supervisor and service provider
- Sent for repair or bench/service evaluation according to site process
Knowing when to stop is proper troubleshooting. Repeated table movement attempts can worsen mechanical damage and may create patient safety risk.
Clinical Use Tip
Do not troubleshoot table movement problems with a patient on the table unless the action is necessary for safe patient removal. Move the patient to another scanner or imaging option first when possible. A CT table that cannot reliably move or report position accurately should not be used for patient imaging.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"CT staff reported the GE Revolution CT table would not move to the selected scan position and displayed a positioning error."
Cause
What was observed during troubleshooting.
Example:
"Physical obstructions and emergency stop status were checked; table movement remained inconsistent with no patient on the table."
Resolution
What action was taken.
Example:
"Scanner was removed from service, labeled Out of Service, and escalated for service evaluation of the table positioning system."
Helpful Details to Include (If Known)
- Outlet or room power status checked
- Emergency stop status
- Exact table motion affected
- Whether movement failed from gantry controls, console controls, or both
- Any error message displayed
- Whether the table moved with no patient present
- Patient load or accessory setup at time of failure
- Obstructions found or ruled out
- Unusual noises, binding, vibration, or motor strain
- Whether actual table position matched console display
- Whether system reset changed the behavior
- Final scanner status
Final Thought
CT table movement problems should be approached carefully because they directly affect patient safety, scan accuracy, and collision risk. Start with simple external causes such as obstructions, emergency stops, accessories, and control response. If the table remains unreliable, stop troubleshooting and escalate. Clear CCR documentation helps service teams understand whether the failure is mechanical, control-related, or position-feedback related.
That is successful troubleshooting.