Skip to main content
Version: Version 3.0 🚧



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.


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

export default function mode() {  return {    id: '',    displayName: '',    onModeEnter: () => {},    onModeExit: () => {},    validationTags: {},    isValidMode: () => {},    routes: [      {        path: '',        init: () => {},        layoutTemplate: () => {},      },    ],    extensions: [],    hangingProtocols: [],    sopClassHandlers: [],    hotkeys: [],  };}
idunique mode id used to refer to the mode
displayNameactual name of the mode being displayed for each study in the study summary panel
onModeEnterhook is called when the mode is entered by the specified route
onModeExithook is called when the mode exited
isValidModeChecks if the mode is valid for a study
routesroute config which defines the route address, and the layout for it
extensionsextensions needed by the mode
hanging protocollist of hanging protocols that the mode should have access to
sopClassHandlerslist of SOPClass modules needed by the mode

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.

To use a module element you can use the ${extensionId}.${moduleType}.${} 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.

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 longitudinal mode which consumes various functionalities from different extensions. Note that, you don't need to have org.ohif.extensionName, this is a pattern we chose to name our OHIF-maintained extensions, you can simply have extensionName as the id for yours and refer to it inside your modes.

export default function mode({ modeConfiguration }) {  return {    /*    ...    */    routes: [      {        /*       ...       */        layoutTemplate: ({ location, servicesManager }) => {          return {            id: ohif.layout,            props: {              leftPanels: [                'org.ohif.measurement-tracking.panelModule.seriesList',              ],              rightPanels: [                'org.ohif.measurement-tracking.panelModule.trackedMeasurements',              ],              viewports: [                {                  namespace:                    'org.ohif.measurement-tracking.viewportModule.cornerstone-tracked',                  displaySetsToDisplay: [                    'org.ohif.default.sopClassHandlerModule.stack',                  ],                },                {                  namespace: 'org.ohif.dicom-sr.viewportModule.dicom-sr',                  displaySetsToDisplay: [                    'org.ohif.dicom-sr.sopClassHandlerModule.dicom-sr',                  ],                },              ],            },          };        },      },    ],    extensions: [      'org.ohif.default',      'org.ohif.cornerstone',      'org.ohif.measurement-tracking',      'org.ohif.dicom-sr',    ],    hangingProtocols: ['org.ohif.default.hangingProtocolModule.petCT'],    sopClassHandlers: [      'org.ohif.default.sopClassHandlerModule.stack',      'org.ohif.dicom-sr.sopClassHandlerModule.dicom-sr',    ],    /*...*/  };}


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


Currently extensions property in the mode config is used to add contextModule of the mentioned extensions to the list of contexts and provide them through out the app. Since extensions are registered by the ExtensionManager, modes have access to the them even if they have not been referred in the mode config file inside extensions property. Read more about extension registration

const { extensions } = mode;
extensions.forEach(extensionId => {  const allRegisteredModuleIds = Object.keys(extensionManager.modulesMap);  const moduleIds = allRegisteredModuleIds.filter(id =>    id.includes(`${extensionId}.contextModule.`)  );
  const modules =;  contextModules = contextModules.concat(modules);});


Currently, you can pass your defined hanging protocols inside the hangingProtocols property of the mode's config. This will get used inside the Mode.jsx to configure the HangingProtocolService.

const { hangingProtocols } = mode;
hangingProtocols.forEach(extentionProtocols => {  const { protocols } = extensionManager.getModuleEntry(extentionProtocols);  HangingProtocolService.addProtocols(protocols);});


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

const { sopClassHandlers } = mode;
DisplaySetService.init(extensionManager, sopClassHandlers);


hotkeys is another property in the configuration of a mode that can be defined to add the specific hotkeys to the viewer at all routes.

// default hotkeysimport { 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,  },]
export default function mode() {  return {    id: '',    displayName: '',    /*    ...    */    hotkeys: [..hotkeys.defaults.hotkeyBindings, ...myHotkeys],  }}


Upon release modes will also be plugged into the app via configuration, but this is still an area which is under development/discussion, and they are currently pulled from the window in beta.

export default function mode() {  return {    id: 'viewer',    displayName: 'Basic Viewer',    onModeEnter: () => {      /**...**/    },    onModeExit: () => {      /**...**/    },    validationTags: {      /**...**/    },    isValidMode: () => {      /**...**/    },    routes: [      {        path: 'longitudinal',        init: () => {          /**...**/        },        layoutTemplate: () => {          /**...**/        },      },    ],    extensions: [      /**...**/    ],    hangingProtocols: [      /**...**/    ],    sopClassHandlers: [      /**...**/    ],    hotkeys: [      /**...**/    ],  };}
window.longitudinalMode = mode({});

and inside @ohif/viewer we have:

if (!appConfig.modes.length) {  appConfig.modes.push(window.longitudinalMode);  // appConfig.modes.push(window.segmentationMode);}