while filling super conducted MRI machine with liguid helium,you should pay more attention to such problems First is the machine of the liguid helium remained in the machine to prevent quench;The second is to prevent ice blockage,and the last is in assuranse to use high purity helium gas While filling super conducted MRI machine with liguid helium,you should pay more attention to such problems First is the machine of the liguid helium remained in the machine to prevent quench;The second is to prevent ice blockage,and the last is in assuranse to use High purity helium gas