MR imaging: info structure in raw data

The info structure is being developed during the entire process of the MR simulation. Each step of the simulation/experiment creates different part of the info structure and/or read informations from other parts of the structure. The info structure consists mainly by the following fields:

  • info.pulseSequence: it holds information regarding the pulse sequence itself, such as:
    • Nx
    • Ny
    • FOVx
    • FOVy
    • dt
    • rBW
    • kspace: this is the most important part of info.pulseSequence since it holds details on how the reconstruction will be/has been performed.
      • Column #1: holds the unique id number of the acquisition (ACQ) object
      • Column #2: holds the time (in μs) of the onset of the ACQ object
      • Column #3: holds the duration (in μs) of the ACQ object
      • Column #4: holds the delay (in μs) of the ACQ object in the block where it belongs
      • Column #5: holds the dwell time (in μs) of the ACQ object
      • Column #6: holds the ISMRMRD encoding counter "kspace_encode_step_1" ("encode step 1" in Bruker, "Frame" in GE, "e1" in Philips and "Line" in Siemens)
      • Column #7: holds the ISMRMRD encoding counter "kspace_encode_step_2" ("encode step 2" in Bruker, "e2" in Philips and "Partition" in Siemens)
      • Column #8: holds the ISMRMRD encoding counter "Average" ("encode step 2" in Bruker, "e2" in Philips and "Partition" in Siemens)
      • Column #9: holds the ISMRMRD encoding counter "Slice" ("Slice" in Bruker, GE and SIEMENS and "Location" in Philips)
      • Column #10: holds the ISMRMRD encoding counter "Contrast" ("Echo" in Bruker, GE, Philips and Siemens)
      • Column #11: holds the ISMRMRD encoding counter "Phase" ("Cardiac Phase" in Philips and "Phase" in Siemens)
      • Column #12: holds the ISMRMRD encoding counter "Repetition" ("Repetition" in Bruker, GE and SIEMENS and "Dynamic Scan" in Philips)
      • Column #13: holds the ISMRMRD encoding counter "Set" ("Row" in Philips and "Set" in Siemens)
      • Column #14: holds the ISMRMRD encoding counter "Segment" ("Segment" in Siemens)
      • Column #15: holds the frequency offset (in Hz) of the ACQ object
      • Column #16: holds the phase offset (in rad) of the ACQ object
      • Column #17: holds the index of the Mx_per_timestep and My_per_timestep where the acquired data for that specific kspace line start
      • Column #18: holds the index of the Mx_per_timestep and My_per_timestep where the acquired data for that specific kspace line stop
  • info.anatomicalModel: it holds information regarding the anatomical model itself.
  • info.reconstruction: it holds information regarding the reconstruction of the acquired simulated data. Part of this structure is being built during the development of the pulse sequence. The info.reconstruction.ismrmrd.header holds the ismrmrd xml header that will be used during the reconstruction process. It follows the structure of the ismrmrd xml schema (ISMRMRD xml schema). 
  • info.simulation: it holds details of the simulation process
  • info.coreMRI: it holds information of the coreMRI system, such as version of the coreMRI framework, etc