class_docstr: Wrapper for Enhanced MR Storage SOP Class
  
  Tested with Philips' Enhanced DICOM implementation.
  
  The specification for the Enhanced MR image IOP / SOP began life as `DICOM
  supplement 49 <ftp://medical.nema.org/medical/dicom/final/sup49_ft.pdf>`_,
  but as of 2016 it is part of the standard. In particular see:
  
  * `A.36 Enhanced MR Information Object Definitions
    <http://dicom.nema.org/medical/dicom/current/output/pdf/part03.pdf#sect_A.36>`_;
  * `C.7.6.16 Multi-Frame Functional Groups Module
    <http://dicom.nema.org/medical/dicom/current/output/pdf/part03.pdf#sect_C.7.6.16>`_;
  * `C.7.6.17 Multi-Frame Dimension Module
    <http://dicom.nema.org/medical/dicom/current/output/pdf/part03.pdf#sect_C.7.6.17>`_.
  
  Attributes
  ----------
  is_multiframe : boolean
      Identifies `dcmdata` as multi-frame
  frames : sequence
      A sequence of ``dicom.dataset.Dataset`` objects populated by the
      ``dicom.dataset.Dataset.PerFrameFunctionalGroupsSequence`` attribute
  shared : object
      The first (and only) ``dicom.dataset.Dataset`` object from a
      ``dicom.dataset.Dataset.SharedFunctionalgroupSequence``.
  
  Methods
  -------
  image_shape(self)
  image_orient_patient(self)
  voxel_sizes(self)
  image_position(self)
  series_signature(self)
  get_data(self)
docstr: Get i, j, k voxel sizes
docstr_tok: ["Get","i",",","j",",","k","voxel","sizes"]
code: def voxel_sizes(self):
      """Get i, j, k voxel sizes"""
      try:
          pix_measures = self.shared.PixelMeasuresSequence[0]
      except AttributeError:
          try:
              pix_measures = self.frames[0].PixelMeasuresSequence[0]
          except AttributeError:
              raise WrapperError("Not enough data for pixel spacing")
      pix_space = pix_measures.PixelSpacing
      try:
          zs = pix_measures.SliceThickness
      except AttributeError:
          zs = self.get("SpacingBetweenSlices")
          if zs is None:
              raise WrapperError("Not enough data for slice thickness")
      # Ensure values are float rather than Decimal
      return tuple(map(float, list(pix_space) + [zs]))
  
imports: import operator
  import warnings
  import numpy
  from nibabel.optpkg import optional_package
  from ..onetime import auto_attr
  from ..openers import ImageOpener
  from .None import csareader
  from .dwiparams import B2q, nearest_pos_semi_def, q2bg
label_desc: Use image node_id 4 for calling the MultiframeWrapper obj's underlying member method code with example usage: obj.voxel_sizes() and returns: tuple