Материал: part17

XXX.3.2.3.2 Volumetric Presentation State Relationship Module Recommendations​

Table XXX.3.2-2. Volumetric Presentation State Relationship Module Recommendations​

Display applications may want to implement mechanisms for detecting when VPS SOP Instances reference exactly the same image​ instances within their Volumetric Presentation State Input Sequence item which creates the volume. This saves memory by loading​ the image instances that create the volume only once.​

TheVolumetricPresentationStatesprovidenomechanismtoexplicitlyspecifythesharingofavolumebymultipleVPSSOPinstances.​

XXX.3.2.3.3 Presentation View Description Module Recommendations​

Table XXX.3.2-3. Presentation View Description Module Recommendations​

XXX.3.3 Replacing Set of Derived Images with Multiple Volumetric Presentation States​

XXX.3.3.1 User Scenario​

In the clinical routine radiologists often create a set of derived images from Planar MPR views that cover a specific anatomic region.​ For example from a head scan a range of oblique transverse Planar MPR views are defined. These views are rendered into separate​ derived CT or Secondary Capture SOP Class instances for conveying the relevant information to the referring clinician.​

Figure XXX.3.3-1. Definition of a range of oblique transverse Planar MPR views on sagittal view of head​

scan for creation of derived images​

However, these derived images depicting the specific anatomy cannot be changed by the display application. The referring clinician​ cannot view other anatomy not shown by the derived images and cannot alter the orientation of the Planar MPR views.​

Alternatively, a set of Planar MPR VPS SOP Instances can be created to depict the slices through the volume. To indicate that these​ Volumetric Presentation State instances are sequentially related, the Presentation Sequence Collection UID (0070,1102) is used to​

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associatetheinstancestoshowtheinstancesaretobedisplayedinsequence,andeachVPSinstanceisgivenaPresentationSequence​ Position Index (0070,1103) value to indicate the order in which the instances occur in the collection (in this case, a spatial sequence).​ In this usage, no animation is specified and it is at the discretion of the display application how these views are to be presented, such​ as by frames in a light-box format or by a manual control stepping through the presentations in one display window.​

XXX.3.3.2 Encoding Outline​

For Planar MPR views that can be moved or rotated by the display application, no special encodings in the Planar MPR VPS SOP​ Instance are necessary.​

Figure XXX.3.3-2. One Volumetric Presentations States is created for each of the MPR views. The VPS​ Instances have the same value of Presentation Display Collection UID (0070,1101)​

In general, the individual VPS instances may have any orientation and be in any location.​

XXX.3.3.3 Encoding Details​

XXX.3.3.3.1 Volumetric Presentation State Identification Module Recommendations​

Table XXX.3.3-1. Volumetric Presentation State Identification Module Recommendations​

XXX.3.4 Replacing Set of Derived Images With Single VPS Using Crosscurve Animation​

XXX.3.4.1 User Scenario​

Another technique for depicting a set of derived images is to have a single Planar MPR VPS SOP Instance that describes an initial​ Planar MPR view, and specify cross-curve animation to generate the other related views. A straight-line curve is specified that begins​ at the center of the initial Planar MPR view and ends at the intended center of the last Planar MPR view of the set. A step size is​ specified to be the distance between the first and last points of the line divided by the number of desired slices minus one. A Recom-​ mended Animation Rate (0070,1A03) is specified if the creator wishes to provide a hint to the display application to scroll through the​ slices in the set, or could be omitted to leave the animation method to the discretion of the display application.​

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H

Curve

MPR view defined in this VPS Instance

A

Animation Step Size

Figure XXX.3.4-1. Additional MPR views are generated by moving the view that is defined in the VPS in​ Animation Step Size (0070,1A05) steps perpendicular along the curve​

XXX.3.4.2 Encoding Outline​

For this case, the curve is a straight line. In general, however, the curve may have any form such as a circular curve to create radial​ MPR views.​

XXX.3.4.3 Encoding Details​

XXX.3.4.3.1 Presentation Animation Module Recommendations​

Table XXX.3.4-1. Presentation Animation Module Recommendations​

XXX.3.5 Volumetric Annotations (example: Trajectory Planning)​

XXX.3.5.1 User Scenario​

The Planar MPR Volumetric Presentation State makes it easy for the receiving display application to enable the user to modify the​ initial view for viewing nearby anatomy. This requires that display relative annotations need to be removed when the initial view gets​ manipulated. Otherwise there would be the risk that the annotations point to the wrong anatomy.​

To give the display application more control over when to show annotations, the Planar MPR Volumetric Presentation State defines​ annotations described by coordinates in the VPS-RCS.​

Asanexample,duringinterventiontrajectoryplanningoneormorestraightlinesrepresentingthetrajectoriesofadevice(e.g.,needle)​ to be introduced during further treatment (e.g., cementoplasty, tumor ablation…) are drawn by the user on a planar MPR view.​

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Needle trajectory

Figure XXX.3.5-1. Needle trajectory on a Planar MPR view​

The Planar MPR VPS does not define how to render the text associated with the annotation or how to connect it to the graphical​ representation of the annotation. This is an implementation decision.​

The creating application derives the 3D coordinates of the needle trajectory from the Planar MPR view and creates a Planar MPR​ VPS SOP instance with the needle trajectory as Volumetric Graphic Annotation. When a user viewing the Presentation State manip-​ ulates the initial Planar MPR view, the display application could control the visibility of the needle trajectory based on the visibility of​ the part of the volume which is crossed by the needle trajectory (e.g., by fading the trajectory in and out, since the intersection of the​ graphic with the plane may only appear as one point). Annotation Clipping (0070,1907) controls whether the out-of-view portion of​ the 3D annotation is displayed or not; see Section C.11.28.1 “Annotation Clipping” in PS3.3 for details.​

For handling multiple annotations in different areas of the volume, applications might provide a list of the annotations which are refer-​ enced in the Presentation State. When a user selects one of the annotations the Planar MPR view could automatically be adjusted​ to optimally show the part of the volume containing the annotation.​

XXX.3.5.2 Encoding Outline​

TheVolumetricPresentationStateprovidestheVolumetricAnnotationSequence(0070,1901)fordefiningannotationsbycoordinates​

in the VPS-RCS.​

TheneedletrajectoryisencodedasalinedescribedbycoordinatesintheVPS-RCS.OptionallyaStructuredReportcanbereferenced​ in order to allow the display application to access additional clinical context.​

XXX.3.5.3 Encoding Details​

XXX.3.5.3.1 Volumetric Graphic Annotation Module Recommendations​

Table XXX.3.5-1. Volumetric Graphic Annotation Module Recommendations​

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The display application could make additional text from the referenced​ Structured Report concept separately available to the user (e.g., on​ mouse-over).​

XXX.3.6 Highlighting Areas of Interest in MPR View​

XXX.3.6.1 User Scenario​

Lung nodules in a volume have been classified by a Computer Aided Detection mechanism into different categories. E.g. small, me-​ dium, large. In planar MPR views the nodules are colorized according to their classification.​

Figure XXX.3.6-1. Planar MPR View with Lung Nodules Colorized by Category​

XXX.3.6.2 Encoding Outline​

The classification of the lung nodules is stored in one or multiple Segmentation IOD instances. For each lung nodule category one​ Segmentation marks the corresponding areas in the volume.​

Forexample,tocreateaPlanarMPRviewwhichshows3lungnodulecategoriesindifferentcolorsthePlanarMPRVPSIODinstance​ defines via the Volumetric Presentation State Display Module a volumetric pipeline with 4 inputs.​

Figure XXX.3.6-2. Planar MPR VPS Pipeline for Colorizing the Lung Nodule Categories​

The same volume data of the lung is used as input for all sub pipelines:​

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