Modes

Overview

A mode can be thought of as a viewer app configured to perform a specific task, such as tracking measurements over time, 3D segmentation, a guided radiological workflow, etc. Addition of modes enables application with many applications as each mode become a mini app configuration behind the scene.

Upon initialization the viewer will consume extensions and modes and build up the route desired, these can then be accessed via the study list, or directly via url parameters.

OHIF-v3 architecture can be seen in the following:

Note: Templates are now a part of “extensions” Routes are configured by modes and/or app

As mentioned, modes are tied to a specific route in the viewer, and multiple modes/routes can be present within a single application. This allows for tremendously more flexibility than before you can now:

• Simultaneously host multiple viewers with for different use cases from within the same app deploy.
• Make radiological viewers for specific purposes/workflows, e.g.:
  • Tracking the size of lesions over time.
  • PET/CT fusion workflows.
  • Guided review workflows optimized for a specific clinical trial.
• Still host one single feature-rich viewer if you desire.

Anatomy

A mode configuration has a route name which is dynamically transformed into a viewer route on initialization of the application. Modes that are available to a study will appear in the study list.

The mode configuration specifies which extensions the mode requires, which LayoutTemplate to use, and what props to pass to the template. For the default template this defines which side panels will be available, as well as what viewports and which displaySets they may hang.

Mode's config is composed of three elements:

• id: the mode id
• modeFactory: the function that returns the mode specific configuration
• extensionDependencies: the list of extensions that the mode requires

that return a config object with certain properties, the high-level view of this config object is:

modes/example/src/index.js

function modeFactory() {
  return {
    id: '',
    version: '',
    displayName: '',
    onModeEnter: () => {},
    onModeExit: () => {},
    validationTags: {},
    isValidMode: () => {},
    routes: [
      {
        path: '',
        init: () => {},
        layoutTemplate: () => {},
      },
    ],
    extensions: extensionDependencies,
    hangingProtocol: [],
    sopClassHandlers: [],
    hotkeys: [],
  };
}

const mode = {
  id,
  modeFactory,
  extensionDependencies,
};

export default mode;

Property	Description
id	unique mode id used to refer to the mode
displayName	actual name of the mode being displayed for each study in the study summary panel
onModeEnter	hook is called when the mode is entered by the specified route
onModeExit	hook is called when the mode exited
validationTags	validationTags
isValidMode	Checks if the mode is valid for a study
routes	route config which defines the route address, and the layout for it
extensionDependencies	extensions needed by the mode
hanging protocol	list of hanging protocols that the mode should have access to
sopClassHandlers	list of SOPClass modules needed by the mode
hotkeys	hotkeys

Consuming Extensions

As mentioned in the Extensions section, in OHIF-v3 developers write their extensions to create re-usable functionalities that later can be used by modes. Now, it is time to describe how the registered extensions will get utilized for a workflow mode via its id.

Each mode has a list of its extensions dependencies which are the the extension name and version number. In addition, to use a module element you can use the ${extensionId}.${moduleType}.${element.name} schema. For instance, if a mode requires the left panel with name of AIPanel that is added by the myAIExtension via the following getPanelModule code, it should address it as myAIExtension.panelModule.AIPanel inside the mode configuration file. In the background OHIF will handle grabbing the correct panel via ExtensionManager.

extensions/myAIExtension/getPanelModule.js

import PanelAI from './PanelAI.js';

function getPanelModule({
  commandsManager,
  extensionManager,
  servicesManager,
}) {
  const wrappedAIPanel = () => {
    return (
      <PanelAI
        commandsManager={commandsManager}
        servicesManager={servicesManager}
      />
    );
  };

  return [
    {
      name: 'AIPanel',
      iconName: 'list-bullets',
      iconLabel: '',
      label: 'AI Panel',
      isDisabled: studies => {}, // optional
      component: wrappedAIPanel,
    },
  ];
}

Now, let's look at a simplified code of the basic viewer mode which consumes various functionalities from different extensions.

const extensionDependencies = {
  '@ohif/extension-default': '^3.0.0',
  '@ohif/extension-cornerstone': '^3.0.0',
  '@ohif/extension-measurement-tracking': '^3.0.0',
};

const id = 'viewer';
const version = '3.0.0';

function modeFactory({ modeConfiguration }) {
  return {
    id,
    // ...
    routes: [
      {
        // ...
        layoutTemplate: ({ location, servicesManager }) => {
          return {
            id: ohif.layout,
            props: {
              leftPanels: ['@ohif/extension-measurement-tracking.panelModule.seriesList'],
              rightPanels: ['@ohif/extension-measurement-tracking.panelModule.trackedMeasurements'],
              viewports: [
                {
                  namespace: '@ohif/extension-measurement-tracking.viewportModule.cornerstone-tracked',
                  displaySetsToDisplay: ['@ohif/extension-default.sopClassHandlerModule.stack'],
                },
              ],
            },
          };
        },
      },
    ],
    extensions: extensionDependencies,
    hangingProtocol: ['@ohif/extension-default.hangingProtocolModule.petCT'],
    sopClassHandlers: ['@ohif/extension-default.sopClassHandlerModule.stack'],
    // ...
  };
}

const mode = {
  id,
  modeFactory,
  extensionDependencies,
}

export default mode

Routes

routes config is an array of route settings, and the overall look and behavior of the viewer at the designated route is defined by the layoutTemplate and init functions for the route. We will learn more about each of the above properties inside the route documentation

HangingProtocols

Currently, you can pass your defined hanging protocols inside the hangingProtocols property of the mode's config. If you specify the hanging protocol explicitly by its name (only string and not array), it will be THE hanging protocol that the mode runs with. However, if you specify an array of hanging protocols, they will get ranked based on the displaySetSelector requirements and the winner will be the hanging protocol that the mode runs with.

SopClassHandlers

Mode's configuration also accepts the sopClassHandler modules that have been added by the extensions. This information will get used to initialize DisplaySetService with the provided SOPClass modules which handles creation of the displaySets.

Hotkeys

hotkeys is another property in the configuration of a mode that can be defined to add the specific hotkeys to the viewer on the mode route. Additionally, the name under which the hotkeys are stored can be configured as hotkeyName. This allows user customization of the mode specific hotkeys.

// default hotkeys
import { utils } from '@ohif/ui';

const { hotkeys } = utils;

const myHotkeys = [
  {
    commandName: 'setToolActive',
    commandOptions: { toolName: 'Zoom' },
    label: 'Zoom',
    keys: ['z'],
    isEditable: true,
  },
  {
    commandName: 'scaleUpViewport',
    label: 'Zoom In',
    keys: ['+'],
    isEditable: true,
  },
]

function modeFactory() {
  return {
    id: '',
    id: '',
    displayName: '',
    /*
    ...
    */
    hotkeys: {
      // The name in preferences to use for this set of hotkeys
      // Allows defining different sets for different modes
      name: 'custom-hotkey-name',
      // And the actual custom values here.
      hotkeys:[..hotkeys.defaults.hotkeyBindings, ...myHotkeys]
    },
  }
}

// exports

Registration

Similar to extension registration, viewer will look inside the pluginConfig.json to find the modes to register.

platform/viewer/pluginConfig.json

// Simplified version of the `pluginConfig.json` file
{
  "extensions": [
    {
      "packageName": "@ohif/extension-cornerstone",
      "version": "3.0.0"
    },
    // ...
  ],
  "modes": [
    {
      "packageName": "@ohif/mode-longitudinal",
      "version": "0.0.1"
    }
  ]
}

Important

You SHOULD NOT directly register modes in the pluginConfig.json file. Use the provided cli to add/remove/install/uninstall modes. Read more here

The final registration and import of the modes happen inside a non-tracked file pluginImport.js (this file is also for internal use only).