Information about phase-encoding using mrinfo


#1

Hello dear Mrtrix experts,

How can one find information about phase-encoding when the output of mrinfo is this:
Image: “dwi.mif”


Dimensions: 128 x 128 x 60 x 34
Voxel size: 1.75 x 1.75 x 2 x ?
Data strides: [ -1 -2 3 4 ]
Format: MRtrix
Data type: unsigned 16 bit integer (little endian)
Intensity scaling: offset = 0, multiplier = 1
Transform: 0.9958 -0.03817 -0.08324 -103.5
0.05144 0.9852 0.1636 -116.5
0.07576 -0.1671 0.983 24.54
EchoTime: 0.059779
FlipAngle: 90
RepetitionTime: 9.02153
command_history: mrconvert “/source/DICOM” “dwi.mif” (version=3.0_RC3-51-g52a2540d)
comments: Anonymous Female 1958 (ANONU9TT1D1LM) [MR] Reg - WIP DTI 32 tra SENSE
study: MR Kopf 3D nativ [ ORIGINAL PRIMARY M_SE M SE ]
DOS: 21/10/2017 22:48:30
dw_scheme: 0,0,0,0
[34 entries] 0.49999761581420898,0.49999761581420898,-0.70711016654968262,800

-0.70710676908493042,4.7632324751134547e-09,0.70710676908493042,800
-0,-0,0,800
mrtrix_version: 3.0_RC3-51-g52a2540d

Shouldn’t there also be a “PhaseEncodingDirection” line? If so, how come I cannot seem to get it with my data?

Best,
Sabina


#2

Hi Sabina,

Sorry for the delay in responding – ISMRM and all that…

Only if that information was present in the DICOM headers. Currently, it seems only Siemens actually store that information – at least in a format that we can decipher. I’m guessing your data are not Siemens…?

If they are Siemens, I note that this seems to be a WIP, so probably not a product sequence? Also, the data appear to have been anonymised, which can remove some critical information depending on how paranoid your anonymisation program is…

Hope this helps,
Donald.