In MRI the commonly field used is -

In MR examination, a large static magnetic field is applied. Field strengths for clinical equipment can vary between 0.2 and 7 T Most commonly used current MRI machines in diagnostic use are of 1.1 and 1.5T. Hence the single best answer would be 1.1 T The field strength of the magnet will influence the quality of the MR image regarding: * chemical shift aifacts * the signal to noise ratio (SNR) * motion sensitivity and susceptibility aifacts.