PP.3.2 2D Derived Images

PP.3.2 2D Derived Images (Current)
Prev	PP.3 3D Ultrasound Solutions in DICOM	Next

The 2D image types represent collections of frames that are related to or derived from the volume data, namely Render Views (projections), separate Multi-Planar Reconstruction (MPR) views, or sets of spatially-related source frames, either parallel or oblique (the cross-hatched images in Figure PP.3-1). The Ultrasound Image and Ultrasound Multi-frame Image IODs are used to represent these related or derived 2D images. The US Image Module for the Ultrasound Image Storage and Ultrasound Multi-frame Image Storage SOP Classes have defined terms for "3D Rendering" (render or MPR views) and "Spatially Related Frames" in value 4 of the Image Type (0008,0008) Attribute to specify that the object contains these views while maintaining backwards compatibility with Ultrasound review applications for frame-by-frame display, which may be displayed sequentially ("fly-through" or temporal) loop display or as a side-by-side ("light-box") display of spatially-related slices. Also, the optional Source Image Sequence (0008,2112) and Derivation Code Sequence (0008,9215) Attributes may be included to more succinctly specify the type of image contained in the instance and the 3D Volume Data set from which it was derived.

2D Derived image instances should be linked to the source 3D Volume Data set through established DICOM reference mechanisms. This is necessary to support the "Two-Stage Review" use case. Consider the following examples:

In the case of a 3D Volume Data set created from a set of spatially-related frames within the ultrasound scanner,
- the Enhanced US Volume instance should include
  1. Referenced Image Sequence (0008,1140) to the source Ultrasound Image and/or Multi-frame Image instances
  2. Referenced Image Purpose of Reference Code Sequence (0040,A170) using (121346, DCM, "Acquisition frames corresponding to volume")
- and the Ultrasound Image and/or Multi-frame Image instances should include:
  1. Referenced Image Sequence (0008,1140) to the 3D Volume Data set
  2. Referenced Image Purpose of Reference Code Sequence (0040,A170) using (121347, DCM, "Volume corresponding to spatially-related acquisition frames")
In the case of an Ultrasound Image or Ultrasound Multi-frame Image instance containing one or more of the spatially-related frames derived from a 3D volume data, the ultrasound image instance should include:
1. Source Image Sequence (0008,2112) referencing the Enhanced US Volume instance
2. Source Image Sequence Purpose of Reference Code Sequence (0040,A170) using (121322, DCM, "Source of Image Processing Operation")
3. Derivation Code Sequence (0008,9215) using (113091, DCM, "Spatially-related frames extracted from the volume")
In the case of separate MPR or 3D rendered views derived from a 3D Volume Data set, the image instance(s) should include:
1. Source Image Sequence (0008,2112) referencing the Enhanced US Volume instance
2. Source Image Sequence Purpose of Reference Code Sequence (0040,A170) using (121322, DCM, "Source of Image Processing Operation")
3. Derivation Code Sequence (0008,9215) using CID 7203 “Image Derivation” code(s) describing the specific derivation operation(s)