[Insight-users] DICOM Image spacing with GDCMImageIO

[Mathieu Malaterre]

On Sun, Jan 18, 2009 at 5:30 PM, C. A. Cois <cacois.itk at gmail.com> wrote:
> I'm using GDCMImageIO to read in some 3D dicom data in ITK.  Its a single
> file dicom format, so I'm using the reader alone without the series reader.
> ITK reads it in with stats:
> Input Image Size: [ 384 384 130 ]
> Input Image Spacing: [ 0.9375 0.9375 1.88 ]
> The size is correct, 384x384 and 130 frames. The spacing, however, I am
> concerned about.  Images along both axes requiring inter-frame spacing look
> stretched.  I looked in the header (pasted below) and can't find any spacing
> information, and certainly no reference to any numbers in [0.9375 0.9375
> 1.88]. I see:
> (0018|0088) Spacing Between Slices = 0.93999999761581
>
> but as I understand it field (0028|0030) should contain pixel spacing, but
> it is empty. So, my question is two-fold:
> 1. Where is ITK getting [ 0.9375 0.9375 1.88 ]?  I am fairly certain this is
> incorrect.

I am fairly certain this is correct :)

How much are you ready to bet ?

This is a "Enhanced MR Image Storage" object. You need to check in the
Sequence to find the Pixel Spacing tag (it is thus not at the root
level).

You can get gdcminfo (from GDCM 2.X dist). Simply type:

  gdcminfo my_input_image.dcm

and it will gives you a nice concise presentation of the properties of
the image.

-- 
Mathieu