Siemens Magnetom Aero 1.5T: knee coil reports no resonance, scans abort
What happened
Reported in the case: when a knee study was started, the system reported no resonance from the knee coil and the scan stopped. The behaviour depended on movement — wiggling the cable or the adapter could trigger it.
What was checked
- The engineers ran the study on a phantom while wiggling the coil cable, to see whether the fault followed movement of the cable.
- They then wiggled and shook the table and the coil adapter to reproduce the vibration-dependent contact and localise the fault inside the adapter.
Cause
The engineers found a poor ground contact inside the coil adapter: the joint was breaking intermittently under vibration, so the system stopped seeing a properly resonating coil and aborted the study.
What was done
The adapter was disassembled, the ground contact was cleaned and the joint was re-soldered. After reassembly the fault no longer reproduced, and the study ran normally — reported as solved in this case.
Safety
MRI safety: the static magnetic field is always on — never take ferromagnetic tools or loose metal parts into the magnet room, and service the adapter outside the exam room where possible.
Lesson: An intermittent no-resonance or coil-loss message can come from a simple mechanical contact fault in the adapter, so reproduce it on a phantom by moving cables and connectors before blaming the coil or the system.
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.