diff --git a/extensions/dicom-sr/src/constants/scoordTypes.js b/extensions/dicom-sr/src/constants/scoordTypes.js
new file mode 100644
index 000000000..9120d71d3
--- /dev/null
+++ b/extensions/dicom-sr/src/constants/scoordTypes.js
@@ -0,0 +1,7 @@
+export default {
+  POINT: 'POINT',
+  MULTIPOINT: 'MULTIPOINT',
+  POLYLINE: 'POLYLINE',
+  CIRCLE: 'CIRCLE',
+  ELLIPSE: 'ELLIPSE',
+};
diff --git a/extensions/dicom-sr/src/constants/toolNames.js b/extensions/dicom-sr/src/constants/toolNames.js
new file mode 100644
index 000000000..ba11ac0ef
--- /dev/null
+++ b/extensions/dicom-sr/src/constants/toolNames.js
@@ -0,0 +1,5 @@
+const TOOL_NAMES = {
+  DICOM_SR_DISPLAY_TOOL: 'DICOMSRDisplayTool',
+};
+
+export default TOOL_NAMES;
diff --git a/extensions/dicom-sr/src/getSopClassHandlerModule.js b/extensions/dicom-sr/src/getSopClassHandlerModule.js
index 7947531c9..c8ff65d73 100644
--- a/extensions/dicom-sr/src/getSopClassHandlerModule.js
+++ b/extensions/dicom-sr/src/getSopClassHandlerModule.js
@@ -1,5 +1,8 @@
 import id from './id';
-import { utils } from '@ohif/core';
+import { utils, classes } from '@ohif/core';
+import addMeasurement from './utils/addMeasurement.js';
+
+const { ImageSet } = classes;
 
 const sopClassHandlerName = 'dicom-sr';
 
@@ -9,8 +12,6 @@ const sopClassUids = [
   '1.2.840.10008.5.1.4.1.1.88.33', //COMPREHENSIVE_SR:
 ];
 
-const scoordTypes = ['POINT', 'MULTIPOINT', 'POLYLINE', 'CIRCLE', 'ELLIPSE'];
-
 const CodeNameCodeSequenceValues = {
   ImagingMeasurementReport: '126000',
   ImageLibrary: '111028',
@@ -20,6 +21,10 @@ const CodeNameCodeSequenceValues = {
   TrackingUniqueIdentifier: '112040',
 };
 
+const RELATIONSHIP_TYPE = {
+  INFERRED_FROM: 'INFERRED FROM',
+};
+
 /**
  * Basic SOPClassHandler:
  * - For all Image types that are stackable, create
@@ -29,16 +34,23 @@ const CodeNameCodeSequenceValues = {
  * @param {SeriesMetadata} series The series metadata object from which the display sets will be created
  * @returns {Array} The list of display sets created for the given series object
  */
-function getDisplaySetsFromSeries(instances) {
+function _getDisplaySetsFromSeries(
+  instances,
+  servicesManager,
+  extensionManager
+) {
   // If the series has no instances, stop here
   if (!instances || !instances.length) {
     throw new Error('No instances were provided');
   }
 
+  const { DisplaySetService } = servicesManager.services;
+  const dataSources = extensionManager.getDataSources();
+  const dataSource = dataSources[0];
+
   const instance = instances[0];
 
   const { StudyInstanceUID, SeriesInstanceUID, SOPInstanceUID } = instance;
-
   const { ConceptNameCodeSequence, ContentSequence } = instance;
 
   if (
@@ -51,10 +63,6 @@ function getDisplaySetsFromSeries(instances) {
     return [];
   }
 
-  const referencedImages = _getReferencedImagesList(ContentSequence);
-
-  const measurements = _getMeasurements(ContentSequence, SOPInstanceUID);
-
   const displaySet = {
     plugin: id,
     Modality: 'SR',
@@ -63,13 +71,141 @@ function getDisplaySetsFromSeries(instances) {
     SeriesInstanceUID,
     StudyInstanceUID,
     SOPClassHandlerId: `${id}.sopClassHandlerModule.${sopClassHandlerName}`,
-    referencedImages,
+    referencedImages: _getReferencedImagesList(ContentSequence),
+    measurements: _getMeasurements(ContentSequence),
   };
 
+  console.log(DisplaySetService);
+
+  // Check currently added displaySets and add measurements if the sources exist.
+  DisplaySetService.activeDisplaySets.forEach(activeDisplaySet => {
+    _checkIfCanAddMeasurementsToDisplaySet(
+      displaySet,
+      activeDisplaySet,
+      dataSource
+    );
+  });
+
+  // Subscribe to new displaySets as the source may come in after.
+  DisplaySetService.subscribe(
+    DisplaySetService.EVENTS.DISPLAY_SETS_ADDED,
+    newDisplaySets => {
+      // If there are still some measurements that have not yet been loaded into cornerstone,
+      // See if we can load them onto any of the new displaySets.
+      newDisplaySets.forEach(newDisplaySet => {
+        _checkIfCanAddMeasurementsToDisplaySet(
+          displaySet,
+          newDisplaySet,
+          dataSource
+        );
+      });
+    }
+  );
+
   return [displaySet];
 }
 
-function getSopClassHandlerModule() {
+function _checkIfCanAddMeasurementsToDisplaySet(
+  srDisplaySet,
+  newDisplaySet,
+  dataSource
+) {
+  let unloadedMeasurements = srDisplaySet.measurements.filter(
+    measurement => measurement.loaded === false
+  );
+
+  if (unloadedMeasurements.length === 0) {
+    // All already loaded!
+    return;
+  }
+
+  if (!newDisplaySet instanceof ImageSet) {
+    // This also filters out _this_ displaySet, as it is not an ImageSet.
+    return;
+  }
+
+  const { sopClassUids, images } = newDisplaySet;
+
+  // Check if any have the newDisplaySet is the correct SOPClass.
+  unloadedMeasurements = unloadedMeasurements.filter(measurement =>
+    measurement.coords.some(coord =>
+      sopClassUids.includes(coord.ReferencedSOPSequence.ReferencedSOPClassUID)
+    )
+  );
+
+  if (unloadedMeasurements.length === 0) {
+    // New displaySet isn't the correct SOPClass, so can't contain the referenced images.
+    return;
+  }
+
+  const SOPInstanceUIDs = [];
+
+  unloadedMeasurements.forEach(measurement => {
+    const { coords } = measurement;
+
+    coords.forEach(coord => {
+      const SOPInstanceUID =
+        coord.ReferencedSOPSequence.ReferencedSOPInstanceUID;
+
+      if (!SOPInstanceUIDs.includes(SOPInstanceUID)) {
+        SOPInstanceUIDs.push(SOPInstanceUID);
+      }
+    });
+  });
+
+  const imageIdsForDisplaySet = dataSource.getImageIdsForDisplaySet(
+    newDisplaySet
+  );
+
+  for (let i = 0; i < images.length; i++) {
+    if (!unloadedMeasurements.length) {
+      // All measurements loaded.
+      break;
+    }
+
+    const image = images[i];
+    const { SOPInstanceUID } = image;
+    if (SOPInstanceUIDs.includes(SOPInstanceUID)) {
+      const imageId = imageIdsForDisplaySet[i];
+
+      for (let j = unloadedMeasurements.length - 1; j >= 0; j--) {
+        const measurement = unloadedMeasurements[j];
+        if (_measurmentReferencesSOPInstanceUID(measurement, SOPInstanceUID)) {
+          addMeasurement(
+            measurement,
+            imageId,
+            newDisplaySet.displaySetInstanceUID
+          );
+
+          unloadedMeasurements.splice(j, 1);
+        }
+      }
+    }
+  }
+}
+
+function _measurmentReferencesSOPInstanceUID(measurement, SOPInstanceUID) {
+  const { coords } = measurement;
+
+  for (let j = 0; j < coords.length; j++) {
+    const coord = coords[j];
+    const { ReferencedSOPInstanceUID } = coord.ReferencedSOPSequence;
+
+    if (ReferencedSOPInstanceUID === SOPInstanceUID) {
+      return true;
+    }
+  }
+}
+
+function getSopClassHandlerModule({ servicesManager, extensionManager }) {
+  const getDisplaySetsFromSeries = instances => {
+    return _getDisplaySetsFromSeries(
+      instances,
+      servicesManager,
+      extensionManager
+    );
+  };
+
   return [
     {
       name: sopClassHandlerName,
@@ -79,10 +215,7 @@ function getSopClassHandlerModule() {
   ];
 }
 
-function _getMeasurements(
-  ImagingMeasurementReportContentSequence,
-  SOPInstanceUID
-) {
+function _getMeasurements(ImagingMeasurementReportContentSequence) {
   const ImagingMeasurements = ImagingMeasurementReportContentSequence.find(
     item =>
       item.ConceptNameCodeSequence.CodeValue ===
@@ -101,7 +234,7 @@ function _getMeasurements(
     MeasurementGroups
   );
 
-  let allMeasurements = [];
+  let measurements = [];
 
   Object.keys(mergedContentSequencesByTrackingUniqueIdentifiers).forEach(
     trackingUniqueIdentifier => {
@@ -110,13 +243,15 @@ function _getMeasurements(
           trackingUniqueIdentifier
         ];
 
-      const measurements = _processMeasurement(mergedContentSequence);
+      const measurement = _processMeasurement(mergedContentSequence);
 
-      if (measurements) {
-        allMeasurements = allMeasurements.concat(measurements);
+      if (measurement) {
+        measurements.push(measurement);
       }
     }
   );
+
+  return measurements;
 }
 
 function _getMergedContentSequencesByTrackingUniqueIdentifiers(
@@ -172,8 +307,6 @@ function _getMergedContentSequencesByTrackingUniqueIdentifiers(
 }
 
 function _processMeasurement(mergedContentSequence) {
-  debugger;
-
   if (
     mergedContentSequence.some(
       group => group.ValueType === 'SCOORD' || group.ValueType === 'SCOORD3D'
@@ -182,34 +315,134 @@ function _processMeasurement(mergedContentSequence) {
     return _processTID1410Measurement(mergedContentSequence);
   }
 
+  return _processNonGeometricallyDefinedMeasurement(mergedContentSequence);
+}
+
+function _processTID1410Measurement(mergedContentSequence) {
+  // Need to deal with TID 1410 style measurements, which will have a SCOORD or SCOORD3D at the top level,
+  // And non-geometric representations where each NUM has "INFERRED FROM" SCOORD/SCOORD3D
+  // TODO -> Look at RelationshipType => Contains means
+
+  const graphicItem = mergedContentSequence.find(
+    group => group.ValueType === 'SCOORD'
+  );
+
+  if (!graphicItem) {
+    console.warn(
+      `graphic ValueType ${graphicItem.ValueType} not currently supported, skipping annotation.`
+    );
+    return;
+  }
+
   const NUMContentItems = mergedContentSequence.filter(
     group => group.ValueType === 'NUM'
   );
 
-  const measurements = [];
+  const measurement = {
+    loaded: false,
+    labels: [],
+    coords: [_getCoordsFromSCOORDOrSCOORD3D(graphicItem)],
+  };
 
   NUMContentItems.forEach(item => {
-    debugger;
+    const { ConceptNameCodeSequence, MeasuredValueSequence } = item;
 
-    const { ContentSequence, MeasuredValueSequence } = item;
-
-    // GET -> REPRESENTATION, REFERNECED IMAGE, measurement value
+    if (MeasuredValueSequence) {
+      measurement.labels.push(
+        _getLabelFromMeasuredValueSequence(
+          ConceptNameCodeSequence,
+          MeasuredValueSequence
+        )
+      );
+    }
   });
 
-  // Need to deal with TID 1410 style measurements, which will have a SCOORD or SCOORD3D at the top level,
-  // And non-geometric representations where each NUM has "INFERRED FROM" SCOORD/SCOORD3D
-
-  // TODO -> Look at RelationshipType => Contains means
-
-  return [];
+  return measurement;
 }
 
-function _processTID1410Measurement(mergedContentSequence) {
-  // TODO
-  console.error('TODO => Process TID1410Measurement');
-  debugger;
+function _processNonGeometricallyDefinedMeasurement(mergedContentSequence) {
+  const NUMContentItems = mergedContentSequence.filter(
+    group => group.ValueType === 'NUM'
+  );
 
-  return [ß];
+  const measurement = {
+    loaded: false,
+    labels: [],
+    coords: [],
+  };
+
+  NUMContentItems.forEach(item => {
+    const {
+      ConceptNameCodeSequence,
+      ContentSequence,
+      MeasuredValueSequence,
+    } = item;
+
+    const { ValueType } = ContentSequence;
+
+    if (!ValueType === 'SCOORD') {
+      console.warn(
+        `Graphic ${ValueType} not currently supported, skipping annotation.`
+      );
+
+      return;
+    }
+
+    const coords = _getCoordsFromSCOORDOrSCOORD3D(ContentSequence);
+
+    if (coords) {
+      measurement.coords.push(coords);
+    }
+
+    if (MeasuredValueSequence) {
+      measurement.labels.push(
+        _getLabelFromMeasuredValueSequence(
+          ConceptNameCodeSequence,
+          MeasuredValueSequence
+        )
+      );
+    }
+  });
+
+  return measurement;
+}
+
+function _getCoordsFromSCOORDOrSCOORD3D(item) {
+  const { ValueType, RelationshipType, GraphicType, GraphicData } = item;
+
+  if (RelationshipType !== RELATIONSHIP_TYPE.INFERRED_FROM) {
+    console.warn(
+      `Relationshiptype === ${RelationshipType}. Cannot deal with NON TID-1400 SCOORD group with RelationshipType !== "INFERRED FROM."`
+    );
+
+    return;
+  }
+
+  const coords = { ValueType, GraphicType, GraphicData };
+
+  // ContentSequence has length of 1 as RelationshipType === 'INFERRED FROM'
+  if (ValueType === 'SCOORD') {
+    const { ReferencedSOPSequence } = item.ContentSequence;
+
+    coords.ReferencedSOPSequence = ReferencedSOPSequence;
+  } else if (ValueType === 'SCOORD3D') {
+    const { ReferencedFrameOfReferenceSequence } = item.ContentSequence;
+
+    coords.ReferencedFrameOfReferenceSequence = ReferencedFrameOfReferenceSequence;
+  }
+
+  return coords;
+}
+
+function _getLabelFromMeasuredValueSequence(
+  ConceptNameCodeSequence,
+  MeasuredValueSequence
+) {
+  const { CodeMeaning } = ConceptNameCodeSequence;
+  const { NumericValue, MeasurementUnitsCodeSequence } = MeasuredValueSequence;
+  const { CodeValue } = MeasurementUnitsCodeSequence;
+
+  return { label: CodeMeaning, value: `${NumericValue} ${CodeValue}` }; // E.g. Long Axis: 31.0 mm
 }
 
 function _getReferencedImagesList(ImagingMeasurementReportContentSequence) {
diff --git a/extensions/dicom-sr/src/index.js b/extensions/dicom-sr/src/index.js
index 533c06381..17e7a43a1 100644
--- a/extensions/dicom-sr/src/index.js
+++ b/extensions/dicom-sr/src/index.js
@@ -1,6 +1,7 @@
 import React from 'react';
 import getSopClassHandlerModule from './getSopClassHandlerModule';
 import id from './id.js';
+import init from './init';
 
 const Component = React.lazy(() => {
   return import('./OHIFCornerstoneSRViewport');
@@ -23,6 +24,10 @@ export default {
    */
   id,
 
+  preRegistration({ servicesManager, configuration = {} }) {
+    init({ servicesManager, configuration });
+  },
+
   /**
    *
    *
diff --git a/extensions/dicom-sr/src/init.js b/extensions/dicom-sr/src/init.js
new file mode 100644
index 000000000..5734103f0
--- /dev/null
+++ b/extensions/dicom-sr/src/init.js
@@ -0,0 +1,21 @@
+import cornerstoneTools from 'cornerstone-tools';
+import DICOMSRDisplayTool from './tools/DICOMSRDisplayTool';
+
+import TOOL_NAMES from './constants/toolNames';
+
+const defaultConfig = {
+  TOOL_NAMES: {
+    DICOM_SR_DISPLAY_TOOL: 'DICOMSRDisplayTool',
+  },
+};
+
+/**
+ * @param {object} configuration
+ */
+export default function init({ configuration = {} }) {
+  const conifg = Object.assign({}, defaultConfig, configuration);
+
+  TOOL_NAMES.DICOM_SR_DISPLAY_TOOL = conifg.TOOL_NAMES.DICOM_SR_DISPLAY_TOOL;
+
+  cornerstoneTools.addTool(DICOMSRDisplayTool);
+}
diff --git a/extensions/dicom-sr/src/tools/DICOMSRDisplayTool.js b/extensions/dicom-sr/src/tools/DICOMSRDisplayTool.js
new file mode 100644
index 000000000..ff0a2eab6
--- /dev/null
+++ b/extensions/dicom-sr/src/tools/DICOMSRDisplayTool.js
@@ -0,0 +1,123 @@
+import { importInternal, getToolState, toolColors } from 'cornerstone-tools';
+
+import TOOL_NAMES from '../constants/toolNames';
+import SCOORD_TYPES from '../constants/scoordTypes';
+
+// Cornerstone 3rd party dev kit imports
+const draw = importInternal('drawing/draw');
+const drawJoinedLines = importInternal('drawing/drawJoinedLines');
+const drawCircle = importInternal('drawing/drawCircle');
+const drawEllipse = importInternal('drawing/drawEllipse');
+const getNewContext = importInternal('drawing/getNewContext');
+const BaseTool = importInternal('base/BaseTool');
+
+/**
+ * @class DICOMSRDisplayTool - Renders DICOMSR data in a read only manner (i.e. as an overlay).
+ * @extends cornerstoneTools.BaseTool
+ */
+export default class DICOMSRDisplayTool extends BaseTool {
+  constructor(props = {}) {
+    const defaultProps = {
+      mixins: ['enabledOrDisabledBinaryTool'],
+      name: TOOL_NAMES.DICOM_SR_DISPLAY_TOOL,
+    };
+
+    const initialProps = Object.assign(defaultProps, props);
+
+    super(initialProps);
+  }
+
+  renderToolData(evt) {
+    const eventData = evt.detail;
+    const { element } = eventData;
+
+    const toolState = getToolState(element, this.name);
+
+    if (!toolState) {
+      return;
+    }
+
+    const options = {
+      color: toolColors.setToolColor(),
+      lineWidth: 2,
+      handleRadius: 6,
+    };
+
+    for (let i = 0; i < toolState.data.length; i++) {
+      const data = toolState.data[i];
+
+      Object.keys(data).forEach(GraphicType => {
+        const renderableData = data[GraphicType];
+
+        switch (GraphicType) {
+          case SCOORD_TYPES.POINT:
+          case SCOORD_TYPES.MULTIPOINT:
+            renderPointOrMultipoint(renderableData, eventData, options);
+            break;
+          case SCOORD_TYPES.POLYLINE:
+            renderPolyLine(renderableData, eventData, options);
+            break;
+          case SCOORD_TYPES.CIRCLE:
+            renderCircle(renderableData, eventData, options);
+            break;
+          case SCOORD_TYPES.ELLIPSE:
+            renderEllipse(renderableData, eventData, options);
+            break;
+        }
+      });
+    }
+  }
+
+  renderPolyLine(renderableData, eventData, options) {
+    const { element } = eventData;
+    const context = getNewContext(eventData.canvasContext.canvas);
+
+    renderableData.forEach(points => {
+      draw(context, context => {
+        drawJoinedLines(context, element, points[0], points, options);
+      });
+    });
+  }
+
+  renderPointOrMultipoint(renderableData, eventData, options) {
+    const context = getNewContext(eventData.canvasContext.canvas);
+
+    renderableData.forEach(points => {
+      draw(context, context => {
+        drawHandles(context, eventData, points, options);
+      });
+    });
+  }
+
+  renderCircle(renderableData, eventData, options) {
+    const { element } = eventData;
+
+    const context = getNewContext(eventData.canvasContext.canvas);
+
+    renderableData.forEach(circle => {
+      const { center, radius } = circle;
+
+      drawCircle(context, element, center, radius, options);
+    });
+  }
+
+  renderEllipse(renderableData, eventData, options) {
+    const { element } = eventData;
+
+    const context = getNewContext(eventData.canvasContext.canvas);
+
+    renderableData.forEach(ellipse => {
+      const { corner1, corner2 } = ellipse;
+
+      drawEllipse(
+        context,
+        element,
+        corner1,
+        corner2,
+        options,
+        'pixel',
+        0 // TODO -> Work our the initial rotation and add it here so we render appropriately rotated ellipses.
+      );
+    });
+  }
+}
diff --git a/extensions/dicom-sr/src/utils/addMeasurement.js b/extensions/dicom-sr/src/utils/addMeasurement.js
new file mode 100644
index 000000000..402082113
--- /dev/null
+++ b/extensions/dicom-sr/src/utils/addMeasurement.js
@@ -0,0 +1,135 @@
+import cornerstoneTools from 'cornerstone-tools';
+import TOOL_NAMES from '../constants/toolNames';
+import SCOORD_TYPES from '../constants/scoordTypes';
+import { cornerstone } from '../../../../platform/core/src';
+
+const globalImageIdSpecificToolStateManager =
+  cornerstoneTools.globalImageIdSpecificToolStateManager;
+
+export default function addMeasurement(
+  measurement,
+  imageId,
+  displaySetInstanceUID
+) {
+  console.log('== ADD MEASUREMENT TO CST ==');
+  console.log(measurement);
+  console.log(imageId);
+  console.log('============================');
+
+  // TODO -> GET TRACKING UID AND ADD IT TO TOOL DATA AND ALSO THE MEASUREMENT ENTRY.
+  // TODO -> Render rotated ellipse .
+
+  debugger;
+
+  const toolName = TOOL_NAMES.DICOM_SR_DISPLAY_TOOL;
+
+  const measurementData = {};
+
+  measurement.coords.forEach(coord => {
+    const { GraphicType, GraphicData } = coord;
+
+    if (measurementData[GraphicType] === undefined) {
+      measurementData[GraphicType] = [];
+    }
+
+    const renderableData = _getRenderableData(GraphicType, GraphicData);
+
+    measurementData[GraphicType].push(renderableData);
+  });
+
+  const toolState = globalImageIdSpecificToolStateManager.saveToolState();
+
+  if (toolState[imageId] === undefined) {
+    toolState[imageId] = {};
+  }
+
+  const imageIdToolState = toolState[imageId];
+
+  // If we don't have tool state for this type of tool, add an empty object
+  if (imageIdToolState[toolName] === undefined) {
+    imageIdToolState[toolName] = {
+      data: [],
+    };
+  }
+
+  const toolData = imageIdToolState[toolName];
+
+  toolData.data.push(measurementData);
+
+  measurement.loaded = true;
+  measurement.imageId = imageId;
+  measurement.displaySetInstanceUID = displaySetInstanceUID;
+  debugger;
+}
+
+function _getRenderableData(GraphicType, GraphicData) {
+  let renderableData;
+
+  switch (GraphicType) {
+    case SCOORD_TYPES.POINT:
+    case SCOORD_TYPES.MULTIPOINT:
+    case SCOORD_TYPES.POLYLINE:
+      renderableData = [];
+
+      for (let i = 0; i < GraphicData.length; i += 2) {
+        renderableData.push({ x: GraphicData[i], y: GraphicData[i + 1] });
+      }
+      break;
+    case SCOORD_TYPES.CIRCLE:
+      const center = { x: GraphicData[0], y: GraphicData[1] };
+      const onPerimeter = { x: GraphicData[2], y: GraphicData[3] };
+
+      const radius = cornerstoneMath.point.distance(center, onPerimeter);
+
+      renderableData = {
+        center,
+        radius,
+      };
+      break;
+    case SCOORD_TYPES.ELLIPSE:
+      console.warn('ROTATED ELLIPSE NOT YET SUPPORTED!');
+
+      const majorAxis = [
+        { x: GraphicData[0], y: GraphicData[1] },
+        { x: GraphicData[2], y: GraphicData[3] },
+      ];
+      const minorAxis = [
+        { x: GraphicData[4], y: GraphicData[5] },
+        { x: GraphicData[6], y: GraphicData[7] },
+      ];
+
+      // Calculate two opposite corners of box defined by two axes.
+
+      const minorAxisLength = cornerstoneMath.point.distance(
+        minorAxis[0],
+        minorAxis[1]
+      );
+
+      const minorAxisDirection = {
+        x: (minorAxis[1].x - minorAxis[0].x) / minorAxisLength,
+        y: (minorAxis[1].y - minorAxis[0].y) / minorAxisLength,
+      };
+
+      const halfMinorAxisLength = minorAxisLength / 2;
+
+      // First end point of major axis + half minor axis vector
+      const corner1 = {
+        x: majorAxis[0].x + minorAxisDirection.x * halfMinorAxisLength,
+        y: majorAxis[0].y + minorAxisDirection.y * halfMinorAxisLength,
+      };
+
+      // Second end point of major axis - half of minor axis vector
+      const corner2 = {
+        x: majorAxis[1].x - minorAxisDirection.x * halfMinorAxisLength,
+        y: majorAxis[1].y - minorAxisDirection.y * halfMinorAxisLength,
+      };
+
+      renderableData = {
+        corner1,
+        corner2,
+      };
+      break;
+  }
+
+  return renderableData;
+}
diff --git a/platform/core/src/extensions/ExtensionManager.js b/platform/core/src/extensions/ExtensionManager.js
index 4e0fda85f..af11f1cf4 100644
--- a/platform/core/src/extensions/ExtensionManager.js
+++ b/platform/core/src/extensions/ExtensionManager.js
@@ -17,9 +17,12 @@ export default class ExtensionManager {
       this.modules[moduleType] = [];
     });
     this.dataSourceMap = {};
+    this.defaultDataSourceName = appConfig.defaultDataSourceName;
+    this.activeDataSource = undefined;
+  }
 
-    console.log('modules map');
-    console.log(this.modulesMap);
+  setActiveDataSource(dataSourceName) {
+    this.activeDataSource = dataSourceName;
   }
 
   /**
@@ -137,6 +140,10 @@ export default class ExtensionManager {
   };
 
   getDataSources = dataSourceName => {
+    if (dataSourceName === undefined) {
+      dataSourceName = this.activeDataSource;
+    }
+
     // Note: this currently uses the data source name, which feels weird...
     return this.dataSourceMap[dataSourceName];
   };
diff --git a/platform/viewer/public/config/default.js b/platform/viewer/public/config/default.js
index 1b22769f0..4aa619bd2 100644
--- a/platform/viewer/public/config/default.js
+++ b/platform/viewer/public/config/default.js
@@ -23,4 +23,5 @@ window.config = {
       },
     },
   ],
+  defaultDataSourceName: 'dicomweb',
 };
diff --git a/platform/viewer/src/appInit.js b/platform/viewer/src/appInit.js
index 973bb7603..f553eaa22 100644
--- a/platform/viewer/src/appInit.js
+++ b/platform/viewer/src/appInit.js
@@ -13,6 +13,8 @@ import {
   // redux as reduxOHIF,
 } from '@ohif/core';
 
+// TODO -> this feels bad.
+
 /**
  * @param {object|func} appConfigOrFunc - application configuration, or a function that returns application configuration
  * @param {object[]} defaultExtensions - array of extension objects
diff --git a/platform/viewer/src/routes/Mode/Mode.jsx b/platform/viewer/src/routes/Mode/Mode.jsx
index 50d29fb1e..371aa4c0d 100644
--- a/platform/viewer/src/routes/Mode/Mode.jsx
+++ b/platform/viewer/src/routes/Mode/Mode.jsx
@@ -27,12 +27,15 @@ export default function ModeRoute({
       : [StudyInstanceUIDs];
 
   const { extensions, sopClassHandlers } = mode;
-  // TODO:
-  // - Check query/params for specific dataSource
-  //     - If provided, query for that dataSource instance
-  //     - If not provided, select default datasource
-  // - Update `extensionManager` to have a method to retrieve the default source
-  const dataSources = extensionManager.getDataSources(dataSourceName);
+
+  if (dataSourceName === undefined) {
+    dataSourceName = extensionManager.defaultDataSourceName;
+  }
+
+  extensionManager.setActiveDataSource(dataSourceName);
+
+  const dataSources = extensionManager.getDataSources();
+
   const dataSource = dataSources[0];
   const route = mode.routes[0];
 
diff --git a/platform/viewer/src/routes/buildModeRoutes.js b/platform/viewer/src/routes/buildModeRoutes.js
index a4822e4cd..bd63e3076 100644
--- a/platform/viewer/src/routes/buildModeRoutes.js
+++ b/platform/viewer/src/routes/buildModeRoutes.js
@@ -68,6 +68,30 @@ export default function buildModeRoutes(
         exact: true,
       });
     });
+
+    const defaultDataSourceName = extensionManager.defaultDataSourceName;
+
+    // Add default DataSource route.
+    const path = `/${mode.id}`;
+
+    // TODO move up.
+    const component = ({ location }) => (
+      <ViewModelProvider>
+        <ModeRoute
+          location={location}
+          mode={mode}
+          dataSourceName={defaultDataSourceName}
+          extensionManager={extensionManager}
+          servicesManager={servicesManager}
+        />
+      </ViewModelProvider>
+    );
+
+    routes.push({
+      path,
+      component,
+      exact: true,
+    });
   });
 
   return routes;
diff --git a/platform/viewer/src/routes/index.js b/platform/viewer/src/routes/index.js
index 8869837e9..8ba005b10 100644
--- a/platform/viewer/src/routes/index.js
+++ b/platform/viewer/src/routes/index.js
@@ -29,8 +29,7 @@ const createRoutes = (
   const routes =
     buildModeRoutes(modes, dataSources, extensionManager, servicesManager) ||
     [];
-  // TODO: Shouldn't need to guard input routes with an empty array?
-  const allRoutes = [...(routes || []), ...bakedInRoutes];
+  const allRoutes = [...routes, ...bakedInRoutes];
 
   console.log(
     'Creating Routes: ',