MR Diffusion Weighted Images – Simultaneous Multi-Slice (SMS) @ Siemens Using DWI SMS with grappa 2 and sms 2 means total pat factor of 4. Another example grappa 2 and sms 3 means total pat factor of 6. In other words, you need to be careful having enough phase oversampling / fov phase % in your phase direction or else you get these pat factor artifacts as seen in the images (red arrow). Second image have more phase oversampling to overcome this issue. #smagnetic #siemens #mri #SMS