Background
contributed by David Clunie; followup on April 30, 2015 QIICR bi-weekly meeting; data uploaded to http://goo.gl/xb1IjG
Comments on the availability of enhanced multiframe DWI datasets
One publicly available example is at:
ftp://medical.nema.org/MEDICAL/Dicom/DataSets/WG16/Philips/EnhancedMR/Brain/
Look in Series 801; there is a DWI with B values of 0 and
I.e., each frame has an
(0x0018,0x9117) MRDiffusionSequence
with either:
(0x0018,0x9087) DiffusionBValue = 0 (0x0018,0x9075) DiffusionDirectionality = NONE
or
(0x0018,0x9087) DiffusionBValue = 1000 (0x0018,0x9075) DiffusionDirectionality = ISOTROPIC
Note also that the type of (inherent) contrast is specified too; in the:
(0x0018,0x9226) MRImageFrameTypeSequence
you will find:
(0x0008,0x9209) AcquisitionContrast = DIFFUSION
Another publicly available set of samples can be found at:
ftp://ftp.ihe.net/Connectathon/samples/RAD-profiles/DIFF_samples/
but these are less useful as a reference since: – the Philips images do not contain useful pixel data – the Hitachi images have a lot of issues with respect to the functional group encoding (try validating them), but do have pixel data
I also have some of Philips diffusion images that have directionality encoded; these are from an IHE test set, are are of a phantom, so are not restricted in their use, but I don’t think there is a public URL for them. Anyway, you can get them from:
https://drive.google.com/open?id=0BzGsmNN8MvZqcG5oSllNMEw5VDA&authuser=0
The image with the directionality contains for the non B0 frames, in
(0x0018,0x9117) MRDiffusionSequence
the attributes:
(0x0018,0x9087) DiffusionBValue = 800 (0x0018,0x9075) DiffusionDirectionality = DIRECTIONAL (0x0018,0x9076) DiffusionGradientDirectionSequence
and in turn DiffusionGradientDirectionSequence
contains:
(0x0018,0x9089) DiffusionGradientOrientation = -1\0\0
or
(0x0018,0x9089) DiffusionGradientOrientation = 0\-1\0
or
(0x0018,0x9089) DiffusionGradientOrientation = 0\0\1
PS. You can find the corresponding “singe frame” (“legacy”) style images for the first case at:
ftp://medical.nema.org/MEDICAL/Dicom/DataSets/WG16/Philips/ClassicSingleFrame/Brain/