Getting all occurencies of a dicom tag in a multiframe dicom

[zeinsalah]

Hi,

considering a multiframe dicom,

1. Is it allowed for slices to have different slices distancies? i.e., is it allowed that sliced are not uniformly distanced?

2. Is it possible to search and get all occurrences of the DCM_ImagePositionPatient from the multiframe dicom? i.e. positions of all slices, e.g. in a vector.
I am using findAndGetOFStringArray(DCM_ImagePositionPatient, value, OFTrue) to get such a tag, but I think it returns the first found occurrence.

Much thanks,

Zein

[Michael Onken]

Hi Zein,

you can use DcmItem's findAndGetElements() method which returns the resulting elements not in a vector but in a stack. Use pop() on the stack until it's empty to access each of the results.

Best,
Michael

[Rich in Soquel]

RE: your 1st question (just in case it's still open)
"1. Is it allowed for slices to have different slices distancies? i.e., is it allowed that sliced are not uniformly distanced?"

If the question is whether such variable spacing can be represented in DICOM, then yes, in at least two different ways:

If the Slice Location Vector tag (0018,2005) is present, then it provides a location (position) for each frame in a multiframe image.

With IVUS or IVOCT modality images, ifa pullback rate if specified, then commonly a Frame Time Vector (0018,1065) gives the time of acquisition of each frame which when multiplied by the pullback rate gives the position of each frame.