Siemens Symphony: image artifacts with normal QA
What happened
Artifacts on images on a Siemens Symphony while QA and the standard test tools report normal results. The engineers suspected the gradient system or the proton frequency.
What was checked
- QA and the standard test tools were run and passed, so the basic image-quality parameters were not the obvious source of the problem.
- Attention moved to the gradient path: the mechanical fastening of the gradient cables was inspected at the point where the round cable transitions to the busbar on the gradient cylinder.
- The focus was the condition of the hardware at that transition, since micro-movement there can pass electrical tests and still corrupt images.
Cause
In this case the cause is reported as probable: loosened fastening of the gradient cables at the cable-to-busbar transition on the gradient cylinder. Vibration and thermal cycling can work such hardware loose over time, and the resulting micro-movement of the cables can show up as image artifacts even when QA and test tools stay within limits — a similar case was resolved exactly this way.
The cause is probable and was not fully confirmed.
What was done
The fix in the similar case was to re-tighten and restore the fastening of the gradient cables at the cable-to-busbar transition, working to the torques and layout given in the manufacturer's service documentation. Since the outcome here is probable rather than confirmed, verify the result with a full quality check before returning the system to clinical use.
Safety
De-energise and lock out the gradient chain before touching any cable run — it carries high peak currents and stored energy — and keep magnet-room discipline throughout: no ferromagnetic tools or loose hardware anywhere near the bore.
Lesson: When images degrade but QA stays clean, look at mechanical integrity first — loose gradient cable hardware is a classic hidden source of artifacts.
Covered in the course: MRI Service — Level 2: Fault-Finding →
Written from an anonymised case shared by service engineers. It is not a manufacturer instruction and grants no authorisation. Independent note; names are trademarks of their owners.