I have fMRI data from a VE Siemens system and after running dcm2niix I get a “BandwidthPerPixelPhaseEncode” value in the .json but do not know how it’s found or calculated. Tried looking in the dicoms themselves and online but still not finding a satisfactory answer. This value wasn’t directly set at the console. Thanks!
dcm2niix uses DICOM tag 0019,1028 for V* and DICOM tag 0021,1153 XA*. You can see validation datasets here. For example, consider series 7 func-bold_task-fa_run-1 where the PDF reports Bandwidth 2298 Hz/Px which is stored in the DICOM as (0018,0095) DS [2298] PixelBandwidth in the READOUT direction. The private DICOM tag (0021,1153) FD 28.934999999999999 reports the BandwidthPerPixelPhaseEncode in milliseconds. Given that 2298 Hz is 0.43ms, and there are 64 columns, one expects 64 * 0.43 = 27.52ms plus the dwell time.
Thank you so much Dr. Rorden, this is very very helpful.
-Sam