Материал: part17

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​

ThetemplatesfortheChestCADSRIODaredefinedinAnnexA“StructuredReportingTemplates(Normative)”inPS3.16.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 obser-​ vation context. It is necessary to update Rendering Intent, and referenced content item identifiers for by-reference relationships,​ within content items paraphrased from another source.​

Document Root

(CONTAINER)

CONTAINS CONTAINS CONTAINS CONTAINS

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.​

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ANALYSES

CAD Processing and

Findings Summary

(CODE)

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

Tree​

TheshadedareainFigureF.1-2demarcatesinformationresultingfromDetection,whereastheunshadedareaisinformationresulting​ fromAnalysis.ThisdistinctionisusedindeterminingwhethertoplacealgorithmidentificationinformationintheSummaryofDetections​ 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.​

OnceaSingleImageFindingorCompositeFeaturehasbeeninstantiated,itmaybereferencedbyanynumberofCompositeFeatures​ higher in the CAD Processing and Findings Summary sub-tree.​

F.2 Chest CAD SR Observation Context Encoding​

•​Any content item in the Content tree that has been inserted (i.e., duplicated) from another SR object instance has a HAS OBS​ CONTEXT relationship to one or more content items that describe the context of the SR object instance from which it originated.​ This mechanism may be used to combine reports (e.g., Chest CAD SR 1, Chest CAD SR 2, Human).​

•​By-reference relationships within Single Image Findings and Composite Features paraphrased from prior Chest CAD SR objects​ need to be updated to properly reference Image Library Entries carried from the prior object to their new positions in the present​ object.​

TheCADProcessingandFindingsSummarysectionoftheSRDocumentContenttreeofaChestCADSRIODmaycontainamixture​ ofcurrentandpriorsingleimagefindingsandcompositefeatures.Thecontentitemsfromcurrentandpriorcontextsaretargetcontent​ items that have a by-value INFERRED FROM relationship to a Composite Feature content item. Content items that come from a​ context other than the Initial Observation Context have a HAS OBS CONTEXT relationship to target content items that describe the​ context of the source document.​

In Figure F.2-1, Composite Feature and Single Image Finding are current, and Single Image Finding (from Prior) is duplicated from​ a prior document.​

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Composite Feature

(CODE)

Source Document

Context Info

Figure F.2-1. Example of Use of Observation Context​

F.3 Chest CAD SR Examples​

The following is a simple and non-comprehensive illustration of an encoding of the Chest CAD SR IOD for chest computer aided de-​ tection results. For brevity, some mandatory content items are not included, such as several acquisition context content items for the​ images in the Image Library.​

F.3.1 Example 1: Lung Nodule Detection With No Findings​

A chest CAD device processes a typical screening chest case, i.e., there is one image and no nodule findings. Chest CAD runs lung​ nodule detection successfully and finds nothing.​

The chest radiograph resembles:​

PROJECTION CHEST

Figure F.3-1. Chest Radiograph as Described in Example 1​

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F.3.2Example2:LungNoduleDetectionWithFindingsandAnatomy/pathologyInterpretation​

A chest CAD device processes a screening chest case with one image, and a lung nodule detected. The chest radiograph resembles:​

PROJECTION CHEST

Figure F.3-2. Chest Radiograph as Described in Example 2​

The content tree structure in this example is complex. Structural illustrations of portions of the content tree are placed within the​ content tree table to show the relationships of data within the tree. Some content items are duplicated (and shown in boldface) to fa-​ cilitate use of the diagrams.​

Chest

CAD Report

CONTAINER

CONTAINS CONTAINS CONTAINS CONTAINS

Figure F.3-3. Content Tree Root of Example 2 Content Tree​

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