Data module shows all data sets loaded into the scene and allows modification of basic properties and perform common operations on all kinds of data, without switching to other modules.
Subject Hierarchytab shows selected nodes in a freely editable folder structure.
Transform Hierarchytab shows data organized by what transforms are applied to them.
All Nodestab shows all nodes in simple list. This is intended for advanced users and troubleshooting.
In Subject Hierarchy, DICOM data is automatically added as patient-study-series hierarchy. Non-DICOM data can be parsed if loaded from a local directory structure, or can be manually organized in tree structure by creating DICOM-like hierarchy or folders.
Subject hierarchy provides features for the underlying data nodes, including cloning, bulk transforming, bulk show/hide, type-specific features, and basic node operations such as delete or rename. Additional plugins provide other type-specific features and general operations, see Subject hierarchy labs page.
Subject hierarchy view
Overview all loaded data objects in the same place, types indicated by icons
Organize data in folders or patient/subject trees
Visualize and bulk-handle lots of data nodes loaded from disk
Easy show/hide of branches of displayable data
Transform whole study (any branch)
Export DICOM data (edit DICOM tags)
Lots of type-specific functionality offered by the plugins
Transform hierarchy view
Manage transformation chains/hierarchies
All nodes view
Developer tool for debugging problems
Create new Subject from scratch
Right-click on the empty area and select ‘Create new subject’
Create new folder
Right-click on an existing item or the empty area and select ‘Create new folder’. Folder type hierarchy item can be converted to Subject or Study using the context menu
Right-click on the node and select ‘Rename’, or double-click the name of a node
Apply transform on node or branch
Double-click the cell of the node or branch to transform in the transform column (same icon as Transforms module), then set the desired transform. If the column is not visible, check the ‘Transforms’ checkbox under the tree. An example can be seen in the top screenshot at Patient 2
Panels and their use
Subject hierarchy tab
Contains all the objects in the Subject hierarchy in a tree representation.
Nodes can be drag&dropped under other nodes, thus re-arranging the tree
New folder or subject can be added by right-clicking the
Sceneitem at the top
Data loaded from DICOM are automatically added to the tree of patient, study, series
Non-DICOM data also appears automatically in Subject hierarchy. There are multiple ways to organize them in hierarchy:
Create hierarchy from loaded directory structureaction in the context menu of the scene (right-click on empty area, see screenshot below). This organizes the nodes according to the local file structure they have been loaded from.
Drag&drop manually under a hierarchy node
Legacy model and annotation hierarchies from old scenes are imported as subject hierarchy
Operations (accessible in the context menu of the nodes by right-clicking them):
Common for all nodes:
Show/hide node or branch: Click on the eye icon
Delete: Delete both data node and SH node
Rename: Rename both data node and SH node
Clone: Creates a copy of the selected node that will be identical in every manner. Its name will contain a
Edit properties: If the role of the node is specified (i.e. its icon is not a question mark), then the corresponding module is opened and the node selected (e.g. Volumes module for volumes)
Create child…: Create a node with the specified type
Transform node or branch: Double-click the cell of the node or branch to transform in the
Applied transformcolumn, then set the desired transform. If the column is not visible, check the ‘Transforms’ checkbox under the tree. An example can be seen in the top screenshot at ‘Day 2’ study
Operations for specific node types:
Volumes: icon, Edit properties and additional information in tooltip
‘Register this…’ action to select fixed image for registration. Right-click the moving image to initiate registration
‘Segment this…’ action allows segmenting the volume, for example, in the Segment Editor module
‘Toggle labelmap outline display’ for labelmaps
Models: icon, Edit properties and additional information in tooltip
SceneViews: icon, Edit properties and Restore scene view
Transforms: icon, additional tooltip info, Edit properties, Invert, Reset to identity
Highlights: when an item is selected, the related items are highlighted. Meaning of colors:
Green: Items referencing the current item directly via DICOM or node references
Yellow: Items referenced by the current item directly via DICOM or node references
Light yellow: Items referenced by the current item recursively via node references
Subject hierarchy item information section: Displays detailed information about the selected subject hierarchy item.
Transform hierarchy tab
Nodes: The view lists all transformable nodes of the scene as a hierarchical tree that describes the relationships between nodes. Nodes are graphical objects such as volumes or models that control the displays in the different views (2D, 3D). To rename an item, double click with the left button on any item (but the scene) in the list. A right click pops up a menu containing different actions: “Insert Transform” creates an identity linear transform node and applies it on the selected node. “Edit properties” opens the module of the node (e.g. “Volumes” for volume nodes, “Models” for model nodes, etc.). “Rename” opens a dialog to rename the node. “Delete” removes the node from the scene. Internal drag-and-drops are supported in the view, while moving a node position within the same parent has no effect, changing the parent of a node has a different meaning depending on the current scene model.
Show MRML ID’s: Show/hide in the tree view a second column containing the node ID of the nodes. Hidden by default
Show hidden nodes: Show/hide the hidden nodes. By default, only the main nodes are shown
All nodes tab
List of all nodes in the scene. Supports Edit properties, Rename, Delete.
Common section for all tabs
Filter: Hide all the nodes not matching the typed string. This can be useful to quickly search for a specific node. Please note that the search is case sensitive
MRML node information: Attribute list of the currently selected node. Attributes can be edited (double click in the “Attribute value” cell), added (with the “Add” button) or removed (with the “Remove” button).
Information for developers
Code snippets accessing and manipulating subject hierarchy items can be found in the script repository.
Implementing new plugins: Plugins are the real power of subject hierarchy, as they provide support for data node types, and add functionality to the context menu items. To create a C++ plugin, implement a child class of qSlicerSubjectHierarchyAbstractPlugin, for Python plugin see below. Many examples can be found in Slicer core and in the SlicerRT extension, look for folders named SubjectHierarchyPlugins.
Writing plugins in Python:
Role plugins: add support for new data node types
Defines: ownership, icon, tooltip, edit properties, help text (in the yellow question mark popup), visibility icon, set/get display visibility, displayed node name (if different than name of the node object)
Existing plugins in Slicer core: Markups, Models, SceneViews, Charts, Folder, Tables, Transforms, LabelMaps, Volumes
Function plugins: add feature in right-click context menu for certain types of nodes
Defines: list of context menu actions for nodes and the scene, types of nodes for which the action shows up, functions handling the defined action
Existing plugins in Slicer core: CloneNode, ParseLocalData, Register, Segment, DICOM, Volumes, Markups, Models, Annotations, Segmentations, Segments, etc.
End-user advocate: Ron Kikinis (SPL, NA-MIC)
Csaba Pinter (PerkLab, Queen’s University)
Julien Finet (Kitware)
Alex Yarmarkovich (Isomics)
Nicole Aucoin (SPL, BWH)
This work is part of the National Alliance for Medical Image Computing (NAMIC), funded by the National Institutes of Health through the NIH Roadmap for Medical Research, Grant U54 EB005149. This work was also funded by An Applied Cancer Research Unit of Cancer Care Ontario with funds provided by the Ministry of Health, Canada