DICOM PS3.17 2019c - Explanatory Information

F Chest CAD (Informative)

This Annex was formerly located in Annex M “Chest CAD (Informative)” in PS3.3 in the 2003 and earlier revisions of the Standard.

F.1 Chest CAD SR Content Tree Structure

The templates for the Chest CAD SR IOD are defined in Annex A “Structured Reporting Templates (Normative)” in PS3.16. Relationships defined in the Chest CAD SR IOD templates are by-value, unless otherwise stated. Content items referenced from another SR object instance, such as a prior Chest CAD SR, are inserted by-value in the new SR object instance, with appropriate original source observation context. It is necessary to update Rendering Intent, and referenced content item identifiers for by-reference relationships, within content items paraphrased from another source.

Top Levels of Chest CAD SR Content Tree

Figure F.1-1. Top Levels of Chest CAD SR Content Tree


The Document Root, Image Library, CAD Processing and Findings Summary, and Summaries of Detections and Analyses sub-trees together form the content tree of the Chest CAD SR IOD. See Annex E for additional explanation of the Summaries of Detections and Analyses sub-trees.

Example of CAD Processing and Findings Summary Sub-Tree of Chest CAD SR Content Tree

Figure F.1-2. Example of CAD Processing and Findings Summary Sub-Tree of Chest CAD SR Content Tree


The shaded area in Figure F.1-2 demarcates information resulting from Detection, whereas the unshaded area is information resulting from Analysis. This distinction is used in determining whether to place algorithm identification information in the Summary of Detections or Summary of Analyses sub-trees.

The identification of a lung nodule within a single image is considered to be a Detection, which results in a Single Image Finding. The temporal correlation of a lung nodule in two instances of the same view taken at different times, resulting in a Composite Feature, is considered Analysis.

Once a Single Image Finding or Composite Feature has been instantiated, it may be referenced by any number of Composite Features higher in the CAD Processing and Findings Summary sub-tree.

DICOM PS3.17 2019c - Explanatory Information