FSE and GRE Artifact

SYSTEM: MR 0.35T Ovation

Hospital: Daqing Oilfield General hospital

PROBLEM/SYMPTOM

The images of FRFSE and GRE protocols has ghost and sometimes low SNR images appear in one series. But SE protocol images are normal.

Please look attach images.

TROUBLESHOOTING HISTORY/HINT

1. These artifacts only occur in the image of FRFSE and GRE protocols, but SE protocol

images never appear . Do Head SPT Quick check, head SNR is marginal(about 8.2).

2. Checked the RF door, lighting power, TCU power, PAC power supply and magnet Display , all ok.

3. Swapped the gradient amplifiers, filters on SRU and cables, the artifact still occurs in the Same protocols.   Page 3 of 3

4. Test below parts in another site, all ok. the gradient PSU, TYMEII , SCA, IPG II, UCERD, RF Amp, RFI, MSHS and Head coil

5. Check DD diode property, DD cables and HV, all normal.

6. Disable the RF signal output of UCERD, the artifact disappeared.

7. Swap Receiver and receive cables and bypass MA, the problem still be there.

8. Disassemble Body coil, place it outside of magnet, connect all cables and scan again, artifacts still exist.

9. We check power supply and ground and find the ground connector on the PP (Magnet Room) is very loose. We tighten it and scan again, head SNR improved

(Head SNR: 8.9)

ROOT CAUSE/SOLUTION

Finally we find that someone connect 1 wire from 1 of 3 live wires of MR equipment power

supply outside of the MR Department without permission. After remove the wire and scan again, system comes normal and head SNR is 9.3.

So the power supply quality will affect image quality.