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What This Guide Helps With
Addresses unavailable patient-table or positioning movement caused by controls, obstructions, emergency states, accessories, positioning, or system readiness conditions.
Step-by-Step Troubleshooting
1. Protect the Patient Before Testing Motion
If a patient is on the table and motion is unreliable, stop nonessential movement and follow the approved patient-removal workflow. Do not continue troubleshooting motion while a patient depends on the system.
Maintain MRI-compatible equipment and Zone IV controls throughout the response.
Expected outcome: The patient is safe and table motion can be evaluated without clinical dependency.
2. Confirm Which Motion Is Unavailable
Determine whether the complaint involves longitudinal table travel, table height, positioning controls, a specific control location, or all patient-positioning movement.
Ask whether the problem is constant or occurs only at a particular table position.
Expected outcome: The affected movement and control location are clearly identified.
3. Inspect for Physical Obstruction
Visually inspect around the patient table, bore entrance, floor path, cables, pads, straps, coils, positioning aids, and nearby equipment.
Remove only items that can be safely repositioned without disturbing scanner hardware.
Expected outcome: The table path and positioning area are clear of external obstructions.
If an obstruction was preventing motion and normal movement returns after removal, proceed to final verification.
4. Check Emergency and Safety Controls
Inspect accessible emergency-stop or motion-stop controls and verify that no obvious safety control has been activated.
Do not bypass a stop circuit or defeat an interlock.
Expected outcome: No externally activated safety control is preventing movement.
5. Verify Scanner Readiness
Confirm that the MRI has completed startup and is not displaying a general system-not-ready condition. Positioning motion may be intentionally unavailable when another subsystem is faulted or initialization is incomplete.
Expected outcome: The scanner is otherwise in a normal state that should permit positioning.
If the system itself is not ready, troubleshoot the broader readiness problem instead of forcing table movement.
6. Inspect Accessible Table Controls
Test only approved user-accessible table controls with the table unloaded when practical. Compare operation from available control locations if the system provides more than one approved control point.
Look for damaged buttons, stuck controls, contamination, or obvious physical damage.
Expected outcome: Controls respond normally or the issue is isolated to a specific external control interface.
If one accessible control works and another does not, remove the scanner from clinical use until the defective positioning control is evaluated if that control is required for safe operation.
7. Check Accessories and Patient-Positioning Items
Verify that coils, pads, supports, straps, cables, and other accessories are installed and routed so they do not interfere with table travel or create tension during movement.
Expected outcome: No accessory or cable routing problem restricts table motion.
8. Test Motion Through a Safe Limited Range
With no patient dependent on the equipment, test the affected positioning function through an appropriate safe range using normal controls.
Stop immediately for binding, grinding, unexpected movement, hesitation, or abnormal sound.
Expected outcome: Table or positioning movement is smooth, controlled, repeatable, and stops normally when commanded.
If normal motion is restored and repeatable, troubleshooting can stop after final verification.
9. Perform Final Functional Verification
Verify all clinically required positioning controls involved in the complaint operate normally. Confirm there is no unexpected motion, obstruction, persistent message, or control failure.
Expected outcome: The table can be positioned reliably using normal controls and the scanner remains ready for use.
If achieved, troubleshooting is complete.
10. Escalate Persistent Motion Problems
If the table will not move, moves unpredictably, binds, generates unusual noise, or repeatedly becomes unavailable without an external cause, stop testing.
Do not access internal drive assemblies, motor controls, or restricted service functions.
Expected outcome: The scanner is removed from service for qualified evaluation.
If the Problem Persists
Common external obstruction, control, accessory, readiness, and positioning causes have been ruled out. The remaining problem may involve table-drive hardware, motion sensors, interlocks, control electronics, system configuration, or another service-level condition.
The MRI system should be:
- Removed from service
- Labeled Out of Service
- Sent for repair or bench/system evaluation as appropriate
- Evaluated using appropriate Canon service documentation and approved test equipment
- Repaired or configured only by qualified personnel
After repair, verify controlled table movement, stopping behavior, positioning functionality, scanner readiness, and any manufacturer-required safety checks before clinical return.
Knowing when to stop external troubleshooting is proper troubleshooting.
Clinical Use Tip
Never test unreliable table motion with a patient on the scanner when the patient can first be safely transferred to another verified workflow.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"MRI staff reported the patient table would not advance into the scanner bore."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found a positioning accessory and cable were interfering with the table travel path."
Resolution
What action was taken.
Example:
"Corrected the accessory and cable routing, verified smooth table travel with normal controls, and confirmed the scanner remained clinically ready."
Helpful Details to Include (If Known)
- Specific motion affected
- Table position when failure occurred
- Control location tested
- Obstruction found
- Coil or accessory setup
- Cable routing condition
- Emergency-control status
- Unusual sound or binding
- Results after correction
- Final table and scanner status
Final Thought
Protect the patient first, eliminate obstruction and control problems before suspecting internal motion hardware, and stop testing whenever movement becomes unpredictable or mechanically abnormal. Verify the complete positioning function before return to service and document the event clearly.
That is successful troubleshooting.