(contributed by David Clunie; followup on April 30, 2015 QIICR bi-weekly meeting)

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://www.dropbox.com/s/hg42y1v15bfevyl/emr_diff_perf_profiles_2010.zip

and can perhaps copy them to somewhere permanent and publicly accessible (and share the link with the QIN folks who were asking about this too).

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/

Created on 30 Apr 2015, Last modified on 30 Apr 2015