diff --git a/Packages/viewerbase/client/components/studyBrowser/thumbnailEntry/thumbnailEntry.js b/Packages/viewerbase/client/components/studyBrowser/thumbnailEntry/thumbnailEntry.js
index 29e96d280..21c7bff6a 100644
--- a/Packages/viewerbase/client/components/studyBrowser/thumbnailEntry/thumbnailEntry.js
+++ b/Packages/viewerbase/client/components/studyBrowser/thumbnailEntry/thumbnailEntry.js
@@ -185,8 +185,7 @@ function thumbnailDragEndHandler(e, target) {
     }
 
     // Rerender the viewport using the drag and drop data
-    rerenderViewportWithNewSeries(element, OHIF.viewer.dragAndDropData);
-    Session.get('UseHangingProtocol', false);
+    WindowManager.loadSeriesInViewport(OHIF.viewer.dragAndDropData, element);
     return false;
 }
 
diff --git a/Packages/viewerbase/client/components/viewer/hangingProtocolButtons/hangingProtocolButtons.html b/Packages/viewerbase/client/components/viewer/hangingProtocolButtons/hangingProtocolButtons.html
index 3c243fb05..a1d931e0a 100644
--- a/Packages/viewerbase/client/components/viewer/hangingProtocolButtons/hangingProtocolButtons.html
+++ b/Packages/viewerbase/client/components/viewer/hangingProtocolButtons/hangingProtocolButtons.html
@@ -1,6 +1,6 @@
 <template name="hangingProtocolButtons">
     <button id="previousPresentationGroup" type="button"
-            class="imageViewerCommand btn btn-sm btn-default"
+            class="btn btn-sm btn-default"
             data-container="body"
             data-toggle="tooltip"
             data-placement="bottom"
@@ -9,7 +9,7 @@
         <span class="fa fa-step-backward"></span>
     </button>
     <button id="nextPresentationGroup" type="button"
-            class="imageViewerCommand btn btn-sm btn-default"
+            class="btn btn-sm btn-default"
             data-container="body"
             data-toggle="tooltip"
             data-placement="bottom"
diff --git a/Packages/viewerbase/client/components/viewer/hangingProtocolButtons/hangingProtocolButtons.js b/Packages/viewerbase/client/components/viewer/hangingProtocolButtons/hangingProtocolButtons.js
index 7bdeff472..b3580815f 100644
--- a/Packages/viewerbase/client/components/viewer/hangingProtocolButtons/hangingProtocolButtons.js
+++ b/Packages/viewerbase/client/components/viewer/hangingProtocolButtons/hangingProtocolButtons.js
@@ -1,7 +1,7 @@
 Template.hangingProtocolButtons.helpers({
     isNextAvailable: function() {
         var presentationGroup = Session.get('WindowManagerPresentationGroup');
-        var numPresentationGroups = WindowManager.getNumPresentationGroups();
+        var numPresentationGroups = Session.get('WindowManagerNumPresentationGroups');
         return presentationGroup < numPresentationGroups;
     },
     isPreviousAvailable: function() {
@@ -9,3 +9,14 @@ Template.hangingProtocolButtons.helpers({
         return presentationGroup > 1;
     }
 });
+
+Template.hangingProtocolButtons.events({
+    'click #previousPresentationGroup': function(e) {
+        $(e.currentTarget).tooltip('hide');
+        WindowManager.previousPresentationGroup();
+    },
+    'click #nextPresentationGroup': function(e) {
+        $(e.currentTarget).tooltip('hide');
+        WindowManager.nextPresentationGroup();
+    }
+});
\ No newline at end of file
diff --git a/Packages/viewerbase/client/components/viewer/imageViewerViewport/imageViewerViewport.js b/Packages/viewerbase/client/components/viewer/imageViewerViewport/imageViewerViewport.js
index a80462407..6270de08c 100644
--- a/Packages/viewerbase/client/components/viewer/imageViewerViewport/imageViewerViewport.js
+++ b/Packages/viewerbase/client/components/viewer/imageViewerViewport/imageViewerViewport.js
@@ -138,13 +138,35 @@ function loadSeriesIntoViewport(data, templateData) {
 
         // If there is a saved object containing Cornerstone viewport data
         // (e.g. scale, invert, window settings) in the input data, apply it now.
-        //
-        // Otherwise, display the loaded image in the viewport element with the
-        // default viewport settings.
-        if (data.viewport) {
+
+        // Check if there are default viewport settings for this modality
+        enabledElement.image = image;
+        enabledElement.viewport = cornerstone.getDefaultViewport(enabledElement.canvas, image);
+        var modalityViewport = getModalityDefaultViewport(series, enabledElement, image.imageId);
+
+        // If no default viewport settings or modality-specific settings exists,
+        // display the loaded image in the viewport element with no loaded viewport
+        // settings.
+        if (modalityViewport) {
+            cornerstone.displayImage(element, image, modalityViewport);
+
+            // Mark that this element should not be fit to the window in the resize listeners
+            enabledElement.fitToWindow = false;
+
+            // Resize the canvas to fit the current viewport element size.
+            cornerstone.resize(element, false);
+
+        } else if (data.viewport) {
             cornerstone.displayImage(element, image, data.viewport);
+
+            // Resize the canvas to fit the current viewport element size.
+            cornerstone.resize(element, true);
         } else {
             cornerstone.displayImage(element, image);
+
+            // Resize the canvas to fit the current viewport element size. Fit the displayed
+            // image to the canvas dimensions.
+            cornerstone.resize(element, true);
         }
 
         // Remove the data for this viewport from the ViewportLoading object
@@ -155,10 +177,6 @@ function loadSeriesIntoViewport(data, templateData) {
         // (e.g. hide the progress text box)
         endLoadingHandler(element);
 
-        // Resize the canvas to fit the current viewport element size. Fit the displayed
-        // image to the canvas dimensions.
-        cornerstone.resize(element, true);
-
         // Remove the 'empty' class from the viewport to hide any instruction text
         element.classList.remove('empty');
 
diff --git a/Packages/viewerbase/client/components/viewer/imageViewerViewports/imageViewerViewports.js b/Packages/viewerbase/client/components/viewer/imageViewerViewports/imageViewerViewports.js
index c9d175031..b4572f309 100644
--- a/Packages/viewerbase/client/components/viewer/imageViewerViewports/imageViewerViewports.js
+++ b/Packages/viewerbase/client/components/viewer/imageViewerViewports/imageViewerViewports.js
@@ -1,6 +1,10 @@
 ViewerWindows = new Meteor.Collection(null);
 ViewerWindows._debugName = 'ViewerWindows';
 
+Template.imageViewerViewports.onCreated(function() {
+   WindowManager.init();
+});
+
 Template.imageViewerViewports.helpers({
     height: function() {
         var viewportRows = this.viewportRows || 1;
@@ -136,10 +140,9 @@ var savedSeriesData,
     savedViewportColumns;
 
 Template.imageViewerViewports.events({
-    'CornerstoneMouseDoubleClick .imageViewerViewport': function(e) {
-        var container = $('.viewerMain').get(0);
+    'dblclick .imageViewerViewport': function(e) {
         var data;
-        var contentId = this.contentId || $('#viewer').parents('.tab-pane.active').attr('id');
+        var contentId = Session.get('activeContentId');
 
         // If there is more than one viewport on screen
         // And one of them is double-clicked, it should be rendered alone
@@ -159,8 +162,7 @@ Template.imageViewerViewports.events({
             };
 
             // Render the imageViewerViewports template with these settings
-            $('#imageViewerViewports').remove();
-            UI.renderWithData(Template.imageViewerViewports, data, container);
+            WindowManager.updateWindows(data);
 
             // Remove the 'zoomed' class from any viewports
             $('.imageViewerViewport').removeClass('zoomed');
@@ -191,8 +193,7 @@ Template.imageViewerViewports.events({
             };
 
             // Render the imageViewerViewports template with these settings
-            $('#imageViewerViewports').remove();
-            UI.renderWithData(Template.imageViewerViewports, data, container);
+            WindowManager.updateWindows(data);
 
             // Add the 'zoomed' class to the lone remaining viewport
             $('.imageViewerViewport').eq(0).addClass('zoomed');
diff --git a/Packages/viewerbase/client/components/viewer/layoutChooser/layoutChooser.js b/Packages/viewerbase/client/components/viewer/layoutChooser/layoutChooser.js
index 88a9e00dd..a2c6b08e2 100644
--- a/Packages/viewerbase/client/components/viewer/layoutChooser/layoutChooser.js
+++ b/Packages/viewerbase/client/components/viewer/layoutChooser/layoutChooser.js
@@ -33,8 +33,6 @@ Template.layoutChooser.events({
         highlightCells(evt.currentTarget);
     },
     'click .layoutChooser table td': function(evt) {
-        $('#imageViewerViewports').remove();
-
         var currentCell = $(evt.currentTarget);
         var rowIndex = currentCell.closest('tr').index();
         var columnIndex = currentCell.index();
@@ -42,10 +40,9 @@ Template.layoutChooser.events({
         // Add 1 because the indices start from zero
         var data = {
             viewportRows: rowIndex + 1,
-            viewportColumns: columnIndex + 1,
+            viewportColumns: columnIndex + 1
         };
         
-        var container = $(".viewerMain").get(0);
-        UI.renderWithData(Template.imageViewerViewports, data, container);
+        WindowManager.setLayout(data);
     }
 });
\ No newline at end of file
diff --git a/Packages/viewerbase/lib/dicomHP.js b/Packages/viewerbase/lib/dicomHP.js
new file mode 100644
index 000000000..cf263af40
--- /dev/null
+++ b/Packages/viewerbase/lib/dicomHP.js
@@ -0,0 +1,273 @@
+
+/**
+ * This is a temporary function which will return a hardcoded hanging protocol as a JavaScript object
+ * The purpose of this is to act as a stub until we are actually parsing DICOM Hanging Protocol files,
+ * since Orthanc doesn't seem to support them yet.
+ *
+ * Soon we will be using instanceDataToJsObject to produce this object from the HangingProtocol WADO
+ * instance
+ *
+ */
+function getMammoHangingProtocol() {
+    var tagValues = {
+        HangingProtocolStorage: '1.2.840.10008.5.1.4.38.1'
+    };
+
+    var protocol = {
+        sopClassUid: tagValues.HangingProtocolStorage,
+        sopInstanceUid: '1.2.840.113986.2.664566.21121125.85669.911', // A random Uid
+        hangingProtocolName: 'MammoCadProtocol',
+        hangingProtocolDescription: 'Mammography screening protocol',
+        hangingProtocolLevel: 'SITE',
+        hangingProtocolCreator: 'Erik',
+        hangingProtocolCreationDateTime: '20020101104200',
+        hangingProtocolDefinitionSequence: [{
+            modality: 'MG',
+            laterality: '',
+            procedureCodeSequence: {
+                codeValue: 98765,
+                codingSchemeDesignator: '99Local',
+                codingSchemeVersion: 1.5,
+                codeMeaning: 'Mammogram'
+            },
+            anatomicRegionSequence: {
+                codeValue: 'T-D1100',
+                codingSchemeDesignator: 'SNM3',
+                codeMeaning: 'BREAST'
+            },
+            reasonForRequestedProcedureCodeSequence: {
+                codeValue: 'I67.1',
+                codingSchemeDesignator: 'I10',
+                codeMeaning: 'Calcification'
+            }
+        }],
+        hangingProtocolUserIdentificationCodeSequence: [],
+        hangingProtocolUserGroupName: 'ABC Hospital',
+        numberOfPriorsReferenced: 1,
+        imageSetsSequence: [{
+            imageSetSelectorSequence: [{
+                ImageSetSelectorUsageFlag: 'NO_MATCH',
+                SelectorAttribute: '00180015',
+                SelectorValueNumber: '1',
+                SelectorAttributeVR: 'CS',
+                SelectorCSValue: 'BREAST'
+            }],
+            timeBasedImageSetsSequence: [{
+                ImageSetNumber: 1,
+                ImageSetSelectorCategory: 'RELATIVE_TIME',
+                RelativeTime: '0\0',
+                RelativeTimeUnits: 'MINUTES',
+                ImageSetLabel: 'Current MG Breast'
+            },
+                {
+                    ImageSetNumber: 2,
+                    ImageSetSelectorCategory: 'ABSTRACT_PRIOR',
+                    AbstractPriorValue: '1\\1',
+                    ImageSetLabel: 'Prior MG Breast'
+                }]
+        }],
+        // Skip Number of Screens for now,
+        // Skip Nominal Screen Definition Sequence for now,
+
+        // http://dicom.nema.org/medical/dicom/current/output/chtml/part03/sect_C.23.3.html
+        DisplaySetsSequence: [
+            {
+                // Left side image (R MLO Current)
+                ImageSetNumber: 1,
+                DisplaySetNumber: 1,
+                DisplaySetPresentationGroup: 1,
+                DisplaySetPresentationGroupDescription: 'Current Mediolateral only',
+                ImageBoxesSequence: [{
+                    DisplayEnvironmentSpatialPosition: '0\0.2\0.16667\0',
+                    ImageBoxNumber: 1,
+                    ImageBoxLayoutType: 'STACK'
+                }],
+                FilterOperationsSequence: [{
+                    SelectorAttributeVR: 'CS',
+                    SelectorCSValue: 'R CC',
+                    FilterByCategory: 'SERIES_DESCRIPTION',
+                    FilterByOperator: 'MEMBER_OF'
+                }]
+            }, {
+                // Right side image (L MLO Current)
+                ImageSetNumber: 1,
+                DisplaySetNumber: 1,
+                DisplaySetPresentationGroup: 1,
+                ImageBoxesSequence: [{
+                    ImageBoxNumber: 1,
+                    ImageBoxLayoutType: 'STACK'
+                }],
+                FilterOperationsSequence: [{
+                    SelectorAttributeVR: 'CS',
+                    SelectorCSValue: 'L CC',
+                    FilterByCategory: 'SERIES_DESCRIPTION',
+                    FilterByOperator: 'MEMBER_OF'
+                }]
+            },
+            {
+                // Left side image (R MLO Current)
+                ImageSetNumber: 1,
+                DisplaySetNumber: 1,
+                DisplaySetPresentationGroup: 2,
+                DisplaySetPresentationGroupDescription: 'Current Mediolateral only',
+                ImageBoxesSequence: [{
+                    DisplayEnvironmentSpatialPosition: '0\0.2\0.16667\0',
+                    ImageBoxNumber: 1,
+                    ImageBoxLayoutType: 'STACK'
+                }],
+                FilterOperationsSequence: [{
+                    SelectorAttributeVR: 'CS',
+                    SelectorCSValue: 'R MLO',
+                    FilterByCategory: 'SERIES_DESCRIPTION',
+                    FilterByOperator: 'MEMBER_OF'
+                }],
+                ReformattingOperationType: '',
+                ReformattingThickness: '',
+                ReformattingInterval: '',
+                ReformattingOperationInitialViewDirection: '',
+                SortingOperationsSequence: [],
+                DisplaySetPatientOrientation: '',
+                VOIType: ''
+            }, {
+                // Right side image (L MLO Current)
+                ImageSetNumber: 1,
+                DisplaySetNumber: 1,
+                DisplaySetPresentationGroup: 2,
+                ImageBoxesSequence: [{
+                    ImageBoxNumber: 1,
+                    ImageBoxLayoutType: 'STACK'
+                }],
+                FilterOperationsSequence: [{
+                    SelectorAttributeVR: 'CS',
+                    SelectorCSValue: 'L MLO',
+                    FilterByCategory: 'SERIES_DESCRIPTION',
+                    FilterByOperator: 'MEMBER_OF'
+                }]
+            }, {
+                // Testing purposes
+                // Left side image (R MLO Current)
+                ImageSetNumber: 1,
+                DisplaySetNumber: 1,
+                DisplaySetPresentationGroup: 3,
+                DisplaySetPresentationGroupDescription: 'Current Mediolateral only',
+                ImageBoxesSequence: [{
+                    DisplayEnvironmentSpatialPosition: '0\0.2\0.16667\0',
+                    ImageBoxNumber: 1,
+                    ImageBoxLayoutType: 'STACK'
+                }],
+                FilterOperationsSequence: [{
+                    SelectorAttributeVR: 'CS',
+                    SelectorCSValue: 'R MLO',
+                    FilterByCategory: 'SERIES_DESCRIPTION',
+                    FilterByOperator: 'MEMBER_OF'
+                }]
+            }, {
+                // Right side image (R CC Current)
+                ImageSetNumber: 1,
+                DisplaySetNumber: 1,
+                DisplaySetPresentationGroup: 3,
+                ImageBoxesSequence: [{
+                    ImageBoxNumber: 1,
+                    ImageBoxLayoutType: 'STACK'
+                }],
+                FilterOperationsSequence: [{
+                    SelectorAttributeVR: 'CS',
+                    SelectorCSValue: 'R CC',
+                    FilterByCategory: 'SERIES_DESCRIPTION',
+                    FilterByOperator: 'MEMBER_OF'
+                }]
+            }],
+        PartialDataDisplayHandling: 'MAINTAIN_LAYOUT',
+        SynchronizedScrollingSequence: [],
+        NavigationIndicatorSequence: []
+    };
+
+    return protocol;
+}
+
+function findSetsByPresentationGroup(DisplaySetsSequence, DisplaySetPresentationGroup) {
+    var presentationGroupSets = [];
+    DisplaySetsSequence.forEach(function(displaySet) {
+        if (displaySet.DisplaySetPresentationGroup === DisplaySetPresentationGroup) {
+            presentationGroupSets.push(displaySet);
+        }
+    });
+    return presentationGroupSets;
+}
+
+function findStudy(displaySet, studies) {
+    // Placeholder for now
+    return studies.find().fetch()[0].studyInstanceUid;
+}
+
+/**
+ * Uses the FilterOperationsSequence information to find
+ * the relevant series for display in this display set
+ *
+ * @param displaySet
+ * @param study
+ * @returns {String} The instance Uid of the series to be displayed
+ */
+function findSeries(displaySet, study) {
+    var categoryDictionary = {
+        SERIES_DESCRIPTION: 'seriesDescription'
+    };
+
+    // TODO=Put these inside a loop? We need to support multiple filter operations,
+    // not just one
+    var filterBy = displaySet.FilterOperationsSequence[0].FilterByCategory;
+    var selectorValue = displaySet.FilterOperationsSequence[0].SelectorCSValue;
+    var filterType = displaySet.FilterOperationsSequence[0].FilterByOperator;
+    var category = categoryDictionary[filterBy];
+
+    var seriesInstanceUid;
+    study.seriesList.forEach(function(series) {
+        // TODO = Add other FilterBy operators
+        if (filterType === 'MEMBER_OF') {
+            if (series[category] === selectorValue) {
+                seriesInstanceUid = series.seriesInstanceUid;
+                return false;
+            }
+        }
+    });
+
+    return seriesInstanceUid;
+}
+
+/**
+ * (Work in progress) Uses the information from a DICOM Hanging Protocol
+ * to identify and display studies and series in the image viewer
+ *
+ * @param hangingProtocol
+ * @param inputData
+ * @returns {Array} Array of viewport data to be displayed
+ */
+function applyDICOMHangingProtocol(hangingProtocol, inputData) {
+    log.info('applyDICOMHangingProtocol');
+    var presentationGroup = inputData.DisplaySetPresentationGroup || 1;
+    var studies = ViewerStudies;
+    var currentDisplaySets = findSetsByPresentationGroup(hangingProtocol.DisplaySetsSequence, presentationGroup);
+
+    var viewportData = {
+        viewports: []
+    };
+
+    currentDisplaySets.forEach(function(displaySet, index) {
+        // TODO= Find study information by image set properties and
+        // image set number of this display set
+        var ImageSetNumber = displaySet.ImageSetNumber;
+
+        studyInstanceUid = findStudy(displaySet, studies);
+
+        var study = ViewerStudies.findOne({studyInstanceUid: studyInstanceUid});
+        seriesInstanceUid = findSeries(displaySet, study);
+
+        viewportData.viewports[index] = {
+            seriesInstanceUid: seriesInstanceUid,
+            studyInstanceUid: studyInstanceUid,
+            currentImageIdIndex: 0
+        };
+    });
+
+    return viewportData;
+}
\ No newline at end of file
diff --git a/Packages/viewerbase/lib/hangingprotocols.js b/Packages/viewerbase/lib/hangingprotocols.js
new file mode 100644
index 000000000..9564a1660
--- /dev/null
+++ b/Packages/viewerbase/lib/hangingprotocols.js
@@ -0,0 +1,172 @@
+/**
+ * This is a temporary function which will return a hardcoded hanging protocol as a JavaScript object
+ */
+getMammoHangingProtocolObject = function() {
+    var protocol = {
+        // Need to expand this to allow real searches for studies
+        studiesNeeded: [
+            'current',
+            'prior'
+        ],
+        primaryModality: 'MG',
+        stages: [{
+            stage: 1,
+            rows: 2,
+            columns: 4,
+            viewports: [{
+                seriesDescription: 'RCC',
+                study: 'prior'
+            }, {
+                seriesDescription: 'LCC',
+                study: 'prior'
+            }, {
+                seriesDescription: 'RMLO',
+                study: 'prior'
+            }, {
+                seriesDescription: 'LMLO',
+                study: 'prior'
+            }, {
+                seriesDescription: 'RCC',
+                study: 'current'
+            }, {
+                seriesDescription: 'LCC',
+                study: 'current'
+            }, {
+                seriesDescription: 'RMLO',
+                study: 'current'
+            }, {
+                seriesDescription: 'LMLO',
+                study: 'current'
+            }
+            ]
+        }, {
+            stage: 2,
+            rows: 1,
+            columns: 2,
+            viewports: [{
+                seriesDescription: 'RCC',
+                study: 'current'
+            }, {
+                seriesDescription: 'LCC',
+                study: 'current'
+            }
+            ]
+        }, {
+            stage: 3,
+            rows: 1,
+            columns: 2,
+            viewports: [{
+                seriesDescription: 'RMLO',
+                study: 'current'
+            }, {
+                seriesDescription: 'LMLO',
+                study: 'current'
+            }
+            ]
+        }, {
+            stage: 4,
+            rows: 1,
+            columns: 2,
+            viewports: [{
+                seriesDescription: 'RCC',
+                study: 'current'
+            }, {
+                seriesDescription: 'RCC',
+                study: 'prior'
+            }
+            ]
+        }, {
+            stage: 5,
+            rows: 1,
+            columns: 2,
+            viewports: [{
+                seriesDescription: 'LCC',
+                study: 'current'
+            }, {
+                seriesDescription: 'LCC',
+                study: 'prior'
+            }
+            ]
+        }, {
+            stage: 6,
+            rows: 1,
+            columns: 2,
+            viewports: [{
+                seriesDescription: 'LMLO',
+                study: 'current'
+            }, {
+                seriesDescription: 'LMLO',
+                study: 'prior'
+            }
+            ]
+        }, {
+            stage: 7,
+            rows: 1,
+            columns: 2,
+            viewports: [{
+                seriesDescription: 'RMLO',
+                study: 'current'
+            }, {
+                seriesDescription: 'RMLO',
+                study: 'prior'
+            }
+            ]
+        }, {
+            stage: 8,
+            rows: 2,
+            columns: 4,
+            viewports: [{
+                seriesDescription: 'RCC',
+                study: 'prior',
+                options: {
+                    includeCADMarkers: true
+                }
+            }, {
+                seriesDescription: 'LCC',
+                study: 'prior',
+                options: {
+                    includeCADMarkers: true
+                }
+            }, {
+                seriesDescription: 'RMLO',
+                study: 'prior',
+                options: {
+                    includeCADMarkers: true
+                }
+            }, {
+                seriesDescription: 'LMLO',
+                study: 'prior',
+                options: {
+                    includeCADMarkers: true
+                }
+            }, {
+                seriesDescription: 'RCC',
+                study: 'current',
+                options: {
+                    includeCADMarkers: true
+                }
+            }, {
+                seriesDescription: 'LCC',
+                study: 'current',
+                options: {
+                    includeCADMarkers: true
+                }
+            }, {
+                seriesDescription: 'RMLO',
+                study: 'current',
+                options: {
+                    includeCADMarkers: true
+                }
+            }, {
+                seriesDescription: 'LMLO',
+                study: 'current',
+                options: {
+                    includeCADMarkers: true
+                }
+            }
+            ]
+        }]
+    };
+
+    return protocol;
+};
diff --git a/Packages/viewerbase/lib/modalityDefaultViewport.js b/Packages/viewerbase/lib/modalityDefaultViewport.js
new file mode 100644
index 000000000..4b4a04f89
--- /dev/null
+++ b/Packages/viewerbase/lib/modalityDefaultViewport.js
@@ -0,0 +1,14 @@
+var modalityViewportSettingsFunctions = {};
+getModalityDefaultViewport = function(series, enabledElement, imageId) {
+    var modality = series.modality;
+
+    if (!modalityViewportSettingsFunctions[modality]) {
+        return;
+    }
+
+    return modalityViewportSettingsFunctions[modality](series, enabledElement, imageId);
+};
+
+setModalityDefaultViewportFunction = function(modality, fn) {
+    modalityViewportSettingsFunctions[modality] = fn;
+};
\ No newline at end of file
diff --git a/Packages/viewerbase/lib/windowManager.js b/Packages/viewerbase/lib/windowManager.js
index 785a819fd..6cffd0796 100644
--- a/Packages/viewerbase/lib/windowManager.js
+++ b/Packages/viewerbase/lib/windowManager.js
@@ -1,169 +1,4 @@
-/**
- * This is a temporary function which will return a hardcoded hanging protocol as a JavaScript object
- */
-function getMammoHangingProtocolObject() {
-
-    var protocol = [{
-            stage: 1,
-            rows: 2,
-            columns: 4,
-            viewports: [{
-                    seriesDescription: 'RCC',
-                    study: 'prior'
-                }, {
-                    seriesDescription: 'LCC',
-                    study: 'prior'
-                }, {
-                    seriesDescription: 'RMLO',
-                    study: 'prior'
-                }, {
-                    seriesDescription: 'LMLO',
-                    study: 'prior'
-                }, {
-                    seriesDescription: 'RCC',
-                    study: 'current'
-                }, {
-                    seriesDescription: 'LCC',
-                    study: 'current'
-                }, {
-                    seriesDescription: 'RMLO',
-                    study: 'current'
-                }, {
-                    seriesDescription: 'LMLO',
-                    study: 'current'
-                }
-            ]
-        }, {
-            stage: 2,
-            rows: 1,
-            columns: 2,
-            viewports: [{
-                    seriesDescription: 'RCC',
-                    study: 'current'
-                }, {
-                    seriesDescription: 'LCC',
-                    study: 'current'
-                }
-            ]
-        }, {
-            stage: 3,
-            rows: 1,
-            columns: 2,
-            viewports: [{
-                    seriesDescription: 'RMLO',
-                    study: 'current'
-                }, {
-                    seriesDescription: 'LMLO',
-                    study: 'current'
-                }
-            ]
-        }, {
-            stage: 4,
-            rows: 1,
-            columns: 2,
-            viewports: [{
-                    seriesDescription: 'RCC',
-                    study: 'current'
-                }, {
-                    seriesDescription: 'RCC',
-                    study: 'prior'
-                }
-            ]
-        }, {
-            stage: 5,
-            rows: 1,
-            columns: 2,
-            viewports: [{
-                    seriesDescription: 'LCC',
-                    study: 'current'
-                }, {
-                    seriesDescription: 'LCC',
-                    study: 'prior'
-                }
-            ]
-        }, {
-            stage: 6,
-            rows: 1,
-            columns: 2,
-            viewports: [{
-                    seriesDescription: 'LMLO',
-                    study: 'current'
-                }, {
-                    seriesDescription: 'LMLO',
-                    study: 'prior'
-                }
-            ]
-        }, {
-            stage: 7,
-            rows: 1,
-            columns: 2,
-            viewports: [{
-                    seriesDescription: 'RMLO',
-                    study: 'current'
-                }, {
-                    seriesDescription: 'RMLO',
-                    study: 'prior'
-                }
-            ]
-        }, {
-            stage: 8,
-            rows: 2,
-            columns: 4,
-            viewports: [{
-                    seriesDescription: 'RCC',
-                    study: 'prior',
-                    options: {
-                        includeCADMarkers: true
-                    }
-                }, {
-                    seriesDescription: 'LCC',
-                    study: 'prior',
-                    options: {
-                        includeCADMarkers: true
-                    }
-                }, {
-                    seriesDescription: 'RMLO',
-                    study: 'prior',
-                    options: {
-                        includeCADMarkers: true
-                    }
-                }, {
-                    seriesDescription: 'LMLO',
-                    study: 'prior',
-                    options: {
-                        includeCADMarkers: true
-                    }
-                }, {
-                    seriesDescription: 'RCC',
-                    study: 'current',
-                    options: {
-                        includeCADMarkers: true
-                    }
-                }, {
-                    seriesDescription: 'LCC',
-                    study: 'current',
-                    options: {
-                        includeCADMarkers: true
-                    }
-                }, {
-                    seriesDescription: 'RMLO',
-                    study: 'current',
-                    options: {
-                        includeCADMarkers: true
-                    }
-                }, {
-                    seriesDescription: 'LMLO',
-                    study: 'current',
-                    options: {
-                        includeCADMarkers: true
-                    }
-                }
-            ]
-        }
-    ];
-
-    return protocol;
-}
+ViewerWindows = new Meteor.Collection(null);
 
 function findSeriesByDescription(seriesDescription, study) {
     var seriesInstanceUid;
@@ -182,335 +17,6 @@ function findSeriesByDescription(seriesDescription, study) {
     return seriesInstanceUid;
 }
 
-/**
- * (Work in progress) Uses the information from a DICOM Hanging Protocol
- * to identify and display studies and series in the image viewer
- *
- * @param hangingProtocol
- * @param inputData
- * @returns {Array} Array of viewport data to be displayed
- */
-function applyHangingProtocol(hangingProtocol, inputData) {
-    var presentationGroup = inputData.DisplaySetPresentationGroup || 1;
-    var studies = ViewerStudies;
-    var currentProtocolData = hangingProtocol[presentationGroup - 1];
-
-    var viewportData = {
-        viewports: [],
-        viewportRows: currentProtocolData.rows,
-        viewportColumns: currentProtocolData.columns
-    };
-
-    var currentStudy = ViewerStudies.find({}, {$sort: {studyDate: 1}}).fetch()[0];
-    var otherStudies = WorklistStudies.find({
-        patientId: currentStudy.patientId,
-        studyInstanceUid: {
-            $ne: currentStudy.studyInstanceUid
-        }
-    }, {$sort: {
-        studyDate: 1
-    }}).fetch();
-    var priorStudy = otherStudies[0];
-
-    currentProtocolData.viewports.forEach(function(viewport, index) {
-        if (viewport.study === 'current') {
-            study = currentStudy;
-        } else if (viewport.study === 'prior') {
-            study = currentStudy;
-            /*ViewerStudies.find({
-                studyInstanceUid: {
-                    $ne: currentStudy.studyInstanceUid
-                }
-            }, {$sort: {studyDate: 1}}).fetch()[0];*/
-        }
-        
-        seriesInstanceUid = findSeriesByDescription(viewport.seriesDescription, study);
-
-        viewportData.viewports[index] = {
-            seriesInstanceUid: seriesInstanceUid,
-            studyInstanceUid: study.studyInstanceUid,
-            currentImageIdIndex: 0,
-            options: viewport.options
-        };
-    });
-
-    return viewportData;
-}
-
-
-/**
- * This is a temporary function which will return a hardcoded hanging protocol as a JavaScript object
- * The purpose of this is to act as a stub until we are actually parsing DICOM Hanging Protocol files,
- * since Orthanc doesn't seem to support them yet.
- *
- * Soon we will be using instanceDataToJsObject to produce this object from the HangingProtocol WADO
- * instance
- *
- */
-function getMammoHangingProtocol() {
-    var tagValues = {
-        HangingProtocolStorage: '1.2.840.10008.5.1.4.38.1'
-    };
-
-    var protocol = {
-        sopClassUid: tagValues.HangingProtocolStorage,
-        sopInstanceUid: '1.2.840.113986.2.664566.21121125.85669.911', // A random Uid
-        hangingProtocolName: 'MammoCadProtocol',
-        hangingProtocolDescription: 'Mammography screening protocol',
-        hangingProtocolLevel: 'SITE',
-        hangingProtocolCreator: 'Erik',
-        hangingProtocolCreationDateTime: '20020101104200',
-        hangingProtocolDefinitionSequence: [{
-                modality: 'MG',
-                laterality: '',
-                procedureCodeSequence: {
-                    codeValue: 98765,
-                    codingSchemeDesignator: '99Local',
-                    codingSchemeVersion: 1.5,
-                    codeMeaning: 'Mammogram'
-                },
-                anatomicRegionSequence: {
-                     codeValue: 'T-D1100',
-                     codingSchemeDesignator: 'SNM3',
-                     codeMeaning: 'BREAST'
-                },
-                reasonForRequestedProcedureCodeSequence: {
-                    codeValue: 'I67.1',
-                    codingSchemeDesignator: 'I10',
-                    codeMeaning: 'Calcification'
-                }
-        }],
-        hangingProtocolUserIdentificationCodeSequence: [],
-        hangingProtocolUserGroupName: 'ABC Hospital',
-        numberOfPriorsReferenced: 1,
-        imageSetsSequence: [{
-            imageSetSelectorSequence: [{
-                ImageSetSelectorUsageFlag: 'NO_MATCH',
-                SelectorAttribute: '00180015',
-                SelectorValueNumber: '1',
-                SelectorAttributeVR: 'CS',
-                SelectorCSValue: 'BREAST'
-            }],
-            timeBasedImageSetsSequence: [{
-                ImageSetNumber: 1,
-                ImageSetSelectorCategory: 'RELATIVE_TIME',
-                RelativeTime: '0\0',
-                RelativeTimeUnits: 'MINUTES',
-                ImageSetLabel: 'Current MG Breast'
-            },
-            {
-                ImageSetNumber: 2,
-                ImageSetSelectorCategory: 'ABSTRACT_PRIOR',
-                AbstractPriorValue: '1\\1',
-                ImageSetLabel: 'Prior MG Breast'
-            }]
-        }],
-        // Skip Number of Screens for now,
-        // Skip Nominal Screen Definition Sequence for now,
-
-        // http://dicom.nema.org/medical/dicom/current/output/chtml/part03/sect_C.23.3.html
-        DisplaySetsSequence: [
-        {
-            // Left side image (R MLO Current)
-            ImageSetNumber: 1,
-            DisplaySetNumber: 1,
-            DisplaySetPresentationGroup: 1,
-            DisplaySetPresentationGroupDescription: 'Current Mediolateral only',
-            ImageBoxesSequence: [{
-                DisplayEnvironmentSpatialPosition: '0\0.2\0.16667\0',
-                ImageBoxNumber: 1,
-                ImageBoxLayoutType: 'STACK'
-            }],
-            FilterOperationsSequence: [{
-                SelectorAttributeVR: 'CS',
-                SelectorCSValue: 'R CC',
-                FilterByCategory: 'SERIES_DESCRIPTION',
-                FilterByOperator: 'MEMBER_OF'
-            }]
-        }, {
-            // Right side image (L MLO Current)
-            ImageSetNumber: 1,
-            DisplaySetNumber: 1,
-            DisplaySetPresentationGroup: 1,
-            ImageBoxesSequence: [{
-                ImageBoxNumber: 1,
-                ImageBoxLayoutType: 'STACK'
-            }],
-            FilterOperationsSequence: [{
-                SelectorAttributeVR: 'CS',
-                SelectorCSValue: 'L CC',
-                FilterByCategory: 'SERIES_DESCRIPTION',
-                FilterByOperator: 'MEMBER_OF'
-            }]
-        },
-            {
-            // Left side image (R MLO Current)
-            ImageSetNumber: 1,
-            DisplaySetNumber: 1,
-            DisplaySetPresentationGroup: 2,
-            DisplaySetPresentationGroupDescription: 'Current Mediolateral only',
-            ImageBoxesSequence: [{
-                DisplayEnvironmentSpatialPosition: '0\0.2\0.16667\0',
-                ImageBoxNumber: 1,
-                ImageBoxLayoutType: 'STACK'
-            }],
-            FilterOperationsSequence: [{
-                SelectorAttributeVR: 'CS',
-                SelectorCSValue: 'R MLO',
-                FilterByCategory: 'SERIES_DESCRIPTION',
-                FilterByOperator: 'MEMBER_OF'
-            }],
-            ReformattingOperationType: '',
-            ReformattingThickness: '',
-            ReformattingInterval: '',
-            ReformattingOperationInitialViewDirection: '',
-            SortingOperationsSequence: [],
-            DisplaySetPatientOrientation: '',
-            VOIType: ''
-        }, {
-            // Right side image (L MLO Current)
-            ImageSetNumber: 1,
-            DisplaySetNumber: 1,
-            DisplaySetPresentationGroup: 2,
-            ImageBoxesSequence: [{
-                ImageBoxNumber: 1,
-                ImageBoxLayoutType: 'STACK'
-            }],
-            FilterOperationsSequence: [{
-                SelectorAttributeVR: 'CS',
-                SelectorCSValue: 'L MLO',
-                FilterByCategory: 'SERIES_DESCRIPTION',
-                FilterByOperator: 'MEMBER_OF'
-            }]
-        }, {
-            // Testing purposes
-            // Left side image (R MLO Current)
-            ImageSetNumber: 1,
-            DisplaySetNumber: 1,
-            DisplaySetPresentationGroup: 3,
-            DisplaySetPresentationGroupDescription: 'Current Mediolateral only',
-            ImageBoxesSequence: [{
-                DisplayEnvironmentSpatialPosition: '0\0.2\0.16667\0',
-                ImageBoxNumber: 1,
-                ImageBoxLayoutType: 'STACK'
-            }],
-            FilterOperationsSequence: [{
-                SelectorAttributeVR: 'CS',
-                SelectorCSValue: 'R MLO',
-                FilterByCategory: 'SERIES_DESCRIPTION',
-                FilterByOperator: 'MEMBER_OF'
-            }]
-        }, {
-            // Right side image (R CC Current)
-            ImageSetNumber: 1,
-            DisplaySetNumber: 1,
-            DisplaySetPresentationGroup: 3,
-            ImageBoxesSequence: [{
-                ImageBoxNumber: 1,
-                ImageBoxLayoutType: 'STACK'
-            }],
-            FilterOperationsSequence: [{
-                SelectorAttributeVR: 'CS',
-                SelectorCSValue: 'R CC',
-                FilterByCategory: 'SERIES_DESCRIPTION',
-                FilterByOperator: 'MEMBER_OF'
-            }]
-        }],
-        PartialDataDisplayHandling: 'MAINTAIN_LAYOUT',
-        SynchronizedScrollingSequence: [],
-        NavigationIndicatorSequence: []
-    };
-
-    return protocol;
-}
-
-function findSetsByPresentationGroup(DisplaySetsSequence, DisplaySetPresentationGroup) {
-    var presentationGroupSets = [];
-    DisplaySetsSequence.forEach(function(displaySet) {
-        if (displaySet.DisplaySetPresentationGroup === DisplaySetPresentationGroup) {
-            presentationGroupSets.push(displaySet);
-        }
-    });
-    return presentationGroupSets;
-}
-
-function findStudy(displaySet, studies) {
-    // Placeholder for now
-    return studies.find().fetch()[0].studyInstanceUid;
-}
-
-/**
- * Uses the FilterOperationsSequence information to find
- * the relevant series for display in this display set
- *
- * @param displaySet
- * @param study
- * @returns {String} The instance Uid of the series to be displayed
- */
-function findSeries(displaySet, study) {
-    var categoryDictionary = {
-        SERIES_DESCRIPTION: 'seriesDescription'
-    };
-
-    // TODO=Put these inside a loop? We need to support multiple filter operations,
-    // not just one
-    var filterBy = displaySet.FilterOperationsSequence[0].FilterByCategory;
-    var selectorValue = displaySet.FilterOperationsSequence[0].SelectorCSValue;
-    var filterType = displaySet.FilterOperationsSequence[0].FilterByOperator;
-    var category = categoryDictionary[filterBy];
-
-    var seriesInstanceUid;
-    study.seriesList.forEach(function(series) {
-        // TODO = Add other FilterBy operators
-        if (filterType === 'MEMBER_OF') {
-            if (series[category] === selectorValue) {
-                seriesInstanceUid = series.seriesInstanceUid;
-                return false;
-            }
-        }
-    });
-
-    return seriesInstanceUid;
-}
-
-/**
- * (Work in progress) Uses the information from a DICOM Hanging Protocol
- * to identify and display studies and series in the image viewer
- *
- * @param hangingProtocol
- * @param inputData
- * @returns {Array} Array of viewport data to be displayed
- */
-function applyDICOMHangingProtocol(hangingProtocol, inputData) {
-    log.info('applyDICOMHangingProtocol');
-    var presentationGroup = inputData.DisplaySetPresentationGroup || 1;
-    var studies = ViewerStudies;
-    var currentDisplaySets = findSetsByPresentationGroup(hangingProtocol.DisplaySetsSequence, presentationGroup);
-
-    var viewportData = {
-        viewports: []
-    };
-
-    currentDisplaySets.forEach(function(displaySet, index) {
-        // TODO= Find study information by image set properties and
-        // image set number of this display set
-        var ImageSetNumber = displaySet.ImageSetNumber;
-
-        studyInstanceUid = findStudy(displaySet, studies);
-
-        var study = ViewerStudies.findOne({studyInstanceUid: studyInstanceUid});
-        seriesInstanceUid = findSeries(displaySet, study);
-
-        viewportData.viewports[index] = {
-            seriesInstanceUid: seriesInstanceUid,
-            studyInstanceUid: studyInstanceUid,
-            currentImageIdIndex: 0
-        };
-    });
-
-    return viewportData;
-}
-
 /**
  * This is an example of a hanging protocol
  * It takes in a set of studies, as well as the
@@ -523,12 +29,13 @@ function applyDICOMHangingProtocol(hangingProtocol, inputData) {
  * @returns {Array}
  */
 function defaultHangingProtocol(inputData) {
-    var studies = ViewerStudies.find().fetch();
+    var studies = ViewerStudies.find({}, {reactive: false}).fetch();
     var viewportRows = inputData.viewportRows;
     var viewportColumns = inputData.viewportColumns;
 
     // This is the most basic hanging protocol.
     var stacks = [];
+    var singleImageStacks = [];
     studies.forEach(function(study) {
         study.seriesList.forEach(function(series) {
             
@@ -543,10 +50,19 @@ function defaultHangingProtocol(inputData) {
                 series: series,
                 study: study
             };
-            stacks.push(stack);
+            
+            // Temporary fragile change to make non-single-image MRs show up first
+            var numFrames = anInstance.numFrames;
+            if (series.instances.length > 1 || numFrames > 1) {
+                stacks.push(stack);
+            } else {
+                singleImageStacks.push(stack);
+            }
         });
     });
 
+    stacks = stacks.concat(singleImageStacks);
+
     var viewportData = {
         viewports: []
     };
@@ -569,38 +85,35 @@ function defaultHangingProtocol(inputData) {
 var hangingProtocol;
 var presentationGroup = 1;
 
-function getHangingProtocol(inputData) {
-    // TODO = Update this to use Collection logic
-    var studies = ViewerStudies.find().fetch();
-
-    if (!studies.length) {
-        log.warn("No studies provided to Hanging Protocol");
+function getHangingProtocol() {
+    console.time('getHangingProtocol');
+    var study = ViewerStudies.findOne();
+    if (!study) {
         return;
     }
 
     // Find the unique modalities in this study
     var modalities = [];
-    studies.forEach(function(study) {
-        study.seriesList.forEach(function(series) {
-            if (modalities.indexOf(series.modality) < 0) {
-                modalities.push(series.modality);
-            }
-        });
+    var seriesDescriptions = [];
+    study.seriesList.forEach(function(series) {
+        if (modalities.indexOf(series.modality) < 0) {
+            modalities.push(series.modality);
+        }
+
+        if (seriesDescriptions.indexOf(series.seriesDescription) < 0) {
+            seriesDescriptions.push(series.seriesDescription);
+        }
     });
 
-    if (modalities.indexOf('MG') > -1) {
-        var hp = getMammoHangingProtocolObject();
-        Session.set('WindowManagerPresentationGroup', presentationGroup);
-        var testData = applyHangingProtocol(hp, inputData);
-        return testData;
-        // Commenting this out for now so we can hardcode a MG protocol
-        /*var hangingProtocol = getMammoHangingProtocol();
-        Session.set('WindowManagerPresentationGroup', presentationGroup);
-        return applyDICOMHangingProtocol(hangingProtocol, inputData);*/
+    if (modalities.indexOf('MG') > -1 &&
+        seriesDescriptions.indexOf('L CC')  > -1 &&
+        seriesDescriptions.indexOf('L MLO') > -1 &&
+        seriesDescriptions.indexOf('R CC')  > -1 &&
+        seriesDescriptions.indexOf('R MLO') > -1) {
+        hangingProtocol = getMammoHangingProtocolObject();
+        console.timeEnd('getHangingProtocol');
+        return hangingProtocol;
     }
-
-    Session.set('WindowManagerPresentationGroup', undefined);
-    return defaultHangingProtocol(inputData);
 }
 
 function setHangingProtocol(protocol) {
@@ -614,6 +127,8 @@ function previousPresentationGroup() {
     log.info('previousPresentationGroup: ' + presentationGroup);
     Session.set('WindowManagerPresentationGroup', presentationGroup);
     Session.set('UseHangingProtocol', Random.id());
+
+    updateWindows();
 }
 
 function nextPresentationGroup() {
@@ -625,13 +140,15 @@ function nextPresentationGroup() {
     log.info('nextPresentationGroup: ' + presentationGroup);
     Session.set('WindowManagerPresentationGroup', presentationGroup);
     Session.set('UseHangingProtocol', Random.id());
+
+    updateWindows();
 }
 
 function getNumPresentationGroups() {
-    // TODO=Pull this information from the largest
-    // value of DisplaySetPresentationGroup in the DisplaySetsSequence
-    // after the DICOM-HP is parsed
-    return 8;
+    if (!hangingProtocol || !hangingProtocol.stages) {
+        return;
+    }
+    return hangingProtocol.stages.length;
 }
 
 function getCurrentPresentationGroup() {
@@ -639,11 +156,392 @@ function getCurrentPresentationGroup() {
 }
 
 function setCurrentPresentationGroup(groupNumber) {
-    // Unused for now
     presentationGroup = groupNumber;
 }
 
+function updateWindows(data) {
+    log.info("updateWindows");
+    console.time('updateWindows');
+    ViewerWindows.remove({});
+
+    // First, retrieve any saved viewport data from this tab
+    //Session.get('activeContentId');
+    var contentId = $(".tabTitle.active a").data('target').replace('#','');
+    var savedData = ViewerData[contentId];
+
+    // Next, check if we are using a hanging protocol
+    var usingHP = savedData.usingHP || Session.get('UseHangingProtocol');
+
+    // Check if there is an applicable protocol
+    var applicableProtocol;
+    if (ViewerData[contentId].applicableProtocol) {
+        applicableProtocol = ViewerData[contentId].applicableProtocol;
+    } else {
+        applicableProtocol = getHangingProtocol();
+        ViewerData[contentId].applicableProtocol = applicableProtocol;
+    }
+    
+
+    // If we are using a hanging protocol, and no inputs have been given to this
+    // function, we should apply the HP now
+    if (applicableProtocol && !data && usingHP !== false) {
+        var hpAppliedSuccessfully = WindowManager.useHangingProtocol(applicableProtocol);
+        if (hpAppliedSuccessfully !== false) {
+            return;
+        }
+    }
+
+    var viewportRows,
+        viewportColumns;
+
+    if (data) {
+        // If data has been specified, we should use this data and tell the viewer that the
+        // use of any protocols has been interrupted.
+        viewportRows = data.viewportRows || 1;
+        viewportColumns = data.viewportColumns || 1;
+    } else {
+        // If no data has been specified, and we are not currently using any protocols,
+        // we should check if we need to apply a HP. If we don't, we should just fill
+        // viewports in order of series for the current study
+
+        // Check if we have any saved viewport layout data
+        // If we do, recover it now
+        viewportRows = savedData.viewportRows || 1;
+        viewportColumns = savedData.viewportColumns || 1;
+    }
+
+    var viewportData;
+    if (data && data.loadedSeriesData && !$.isEmptyObject(data.loadedSeriesData)) {
+        viewportData = {
+            viewports: data.loadedSeriesData
+        };
+    } else if (!$.isEmptyObject(savedData.loadedSeriesData)) {
+        viewportData = {
+            viewports: savedData.loadedSeriesData
+        };
+    }
+
+    var stacksByViewport = defaultHangingProtocol({
+        viewportRows: viewportRows,
+        viewportColumns: viewportColumns
+    });
+
+
+    // Update viewerData
+    ViewerData[contentId].studies = ViewerStudies.find().fetch();
+    ViewerData[contentId].usingHP = false;
+    ViewerData[contentId].viewportRows = viewportRows;
+    ViewerData[contentId].viewportColumns = viewportColumns;
+    Session.set("ViewerData", ViewerData);
+
+    var numViewports = viewportRows * viewportColumns;
+
+    var windowData = [];
+    for (var i=0; i < numViewports; ++i) {
+        if (viewportData && !$.isEmptyObject(viewportData.viewports[i])) {
+            dataToUse = viewportData.viewports[i];
+        } else if (stacksByViewport && !$.isEmptyObject(stacksByViewport.viewports[i])) {
+            dataToUse = stacksByViewport.viewports[i];
+        }
+
+        var window = {
+            viewportIndex: i,
+            // These two are necessary because otherwise the width and height helpers
+            // don't get the right data context. Seems to be related to the "each" loop.
+            viewportColumns: viewportColumns,
+            viewportRows: viewportRows,
+            seriesInstanceUid: dataToUse.seriesInstanceUid,
+            studyInstanceUid: dataToUse.studyInstanceUid,
+            currentImageIdIndex: dataToUse.currentImageIdIndex,
+            viewport: dataToUse.viewport
+        };
+
+        windowData.push(window);
+    }
+
+    // Here we will find out if we need to load any other studies into the viewer
+    var studiesReady = loadMissingStudiesIntoCollection(windowData, ViewerStudies);
+    console.timeEnd('updateWindows');
+
+    studiesReady.then(function() {
+        if (contentId !== Session.get('activeContentId')) {
+            log.warn("Tab changed during study load, Stopping.");
+            return false;
+        }
+
+        windowData.forEach(function(window) {
+            ViewerWindows.insert(window);
+        });
+        console.timeEnd('updateWindows');
+    }, function(error) {
+        log.warn(error);
+    });
+
+}
+
+function loadMissingStudiesIntoCollection(data, collection) {
+    // We will make a list of unique studyInstanceUids
+    var uniqueStudyInstanceUids = [];
+
+    var deferredList = [];
+    var loadingDeferred = $.Deferred();
+
+    data.forEach(function(inputData) {
+        var deferred = $.Deferred();
+
+        var studyInstanceUid = inputData.studyInstanceUid;
+        if (!studyInstanceUid) {
+            return;
+        }
+
+        // If this studyInstanceUid is already in the list, stop here
+        if (uniqueStudyInstanceUids.indexOf(studyInstanceUid) > -1) {
+            return;
+        }
+
+        // Otherwise, add it to the list
+        uniqueStudyInstanceUids.push(studyInstanceUid);
+
+        // Check that we already have this study in ViewerStudies
+        var loadedStudy = collection.findOne({
+            studyInstanceUid: studyInstanceUid
+        }, {
+            reactive: false
+        });
+
+        if (loadedStudy) {
+            return;
+        }
+
+        deferredList.push(deferred);
+
+        // If any of the associated studies is not already loaded, load it now
+        getStudyMetadata(studyInstanceUid, function(study) {
+            if (!study) {
+                deferred.reject();
+            }
+            // Sort the study's series and instances by series and instance number
+            sortStudy(study);
+
+            // Insert it into the ViewerStudies Collection
+            collection.insert(study);
+            deferred.resolve();
+        });
+    });
+
+    // When all necessary studies are loaded, resolve the primary deferred
+    $.when.apply($, deferredList).done(function() {
+        loadingDeferred.resolve();
+    });
+
+    return loadingDeferred.promise();
+}
+
+function loadSeriesInViewport(seriesData, element) {
+    rerenderViewportWithNewSeries(element, seriesData);
+    Session.set('UseHangingProtocol', false);
+}
+
+function initialize() {
+    updateWindows();
+}
+
+function setLayout (data) {
+    WindowManager.updateWindows(data);
+}
+
+function sameSeriesAsCurrent(study, currentStudy, modality) {
+    if (!study.seriesList || !study.seriesList.length) {
+        return false;
+    }
+
+    var currentStudyUniqueSeriesDescriptions = [];
+    currentStudy.seriesList.forEach(function(series) {
+        if (currentStudyUniqueSeriesDescriptions.indexOf(series.seriesDescription) > -1 ||
+            series.modality !== modality) {
+            return;
+        }
+        currentStudyUniqueSeriesDescriptions.push(series.seriesDescription);
+    });
+
+    var uniqueSeriesDescriptions = [];
+    study.seriesList.forEach(function(series) {
+        if (uniqueSeriesDescriptions.indexOf(series.seriesDescription) > -1 ||
+            series.modality !== modality) {
+            return;
+        }
+        uniqueSeriesDescriptions.push(series.seriesDescription);
+    });
+
+    var sortFirst = true;
+    return arraysEqual(currentStudyUniqueSeriesDescriptions, uniqueSeriesDescriptions, sortFirst);
+}
+
+function applyStage(applicableProtocol, currentStudy) {
+    var currentProtocolData = applicableProtocol.stages[presentationGroup - 1];
+
+    var viewportRows = currentProtocolData.rows;
+    var viewportColumns = currentProtocolData.columns;
+
+    var study;
+    var priorStudyInstanceUid;
+    currentProtocolData.viewports.forEach(function(viewport, viewportIndex) {
+        if (viewport.study === 'current') {
+            study = currentStudy;
+        } else if (viewport.study === 'prior') {
+            study = ViewerStudies.findOne({
+                windowManagerDescription: 'prior'
+            });
+        }
+
+        var seriesInstanceUid,
+            studyInstanceUid;
+        if (study) {
+            seriesInstanceUid = findSeriesByDescription(viewport.seriesDescription, study);
+            studyInstanceUid = study.studyInstanceUid;
+        }
+
+        var window = {
+            viewportIndex: viewportIndex,
+            viewportRows: viewportRows,
+            viewportColumns: viewportColumns,
+            seriesInstanceUid: seriesInstanceUid,
+            studyInstanceUid: studyInstanceUid,
+            currentImageIdIndex: 0,
+            options: viewport.options
+        };
+
+        ViewerWindows.insert(window);
+    });
+
+    // Update viewerData
+    var contentId = $(".tabTitle.active a").data('target').replace('#','');
+    ViewerData[contentId].usingHP = true;
+    ViewerData[contentId].viewportRows = viewportRows;
+    ViewerData[contentId].viewportColumns = viewportColumns;
+    Session.set("ViewerData", ViewerData);
+
+    console.timeEnd('useHangingProtocol');
+}
+
+function useHangingProtocol(applicableProtocol) {
+    console.time('useHangingProtocol');
+    log.info('Using hanging protocol');
+
+    var currentPresentationGroup = presentationGroup;
+
+    Session.set('WindowManagerNumPresentationGroups', getNumPresentationGroups());
+    Session.set('WindowManagerPresentationGroup', presentationGroup);
+    Session.set('UseHangingProtocol', Random.id());
+
+    var currentStudy = ViewerStudies.findOne({}, {reactive: false});
+
+    var priorStudy = ViewerStudies.findOne({
+        windowManagerDescription: 'prior'
+    });
+
+    if (priorStudy) {
+        applyStage(applicableProtocol, currentStudy);
+        return true;
+    }
+
+    var studyInstanceUidList = [];
+
+    var otherStudies = WorklistStudies.find({
+        patientId: currentStudy.patientId,
+        studyInstanceUid: {
+            $ne: currentStudy.studyInstanceUid
+        },
+        studyDate: {
+            $lt: currentStudy.studyDate
+        }
+    }, {
+        reactive: false,
+        sort: {
+            studyDate: -1
+        }
+    }).forEach(function(study) {
+        studyInstanceUidList.push(study.studyInstanceUid);
+    });
+
+    if (!studyInstanceUidList.length) {
+        return false;
+    }
+
+    var contentId = Session.get('activeContentId');
+
+    var studyInstanceUid;
+    var modality = applicableProtocol.primaryModality;
+    findMatchingStudies(studyInstanceUidList, currentStudy, modality, function(matchingStudy) {
+        if (contentId !== Session.get('activeContentId')) {
+            log.warn("Tab changed during study load, Stopping.");
+            return false;
+        }
+
+        if (!matchingStudy) {
+            return false;
+        }
+
+        log.info('Matching study found');
+
+        sortStudy(matchingStudy);
+        matchingStudy.windowManagerDescription = "prior";
+        ViewerStudies.insert(matchingStudy);
+
+        if (presentationGroup !== currentPresentationGroup) {
+            log.warn('Presentation group changed while studies were loading');
+            return;
+        }
+
+        applyStage(applicableProtocol, currentStudy);
+        return true;
+    });
+}
+
+function findMatchingStudies(studyInstanceUidList, currentStudy, modality, doneCallback) {
+    if (!studyInstanceUidList.length) {
+        return;
+    }
+
+    console.log(studyInstanceUidList);
+    studyInstanceUid = studyInstanceUidList[0];
+    var studyExists = ViewerStudies.findOne({
+        studyInstanceUid: studyInstanceUid
+    }, {
+        reactive: false
+    });
+
+    if (studyExists) {
+        return;
+    }
+    
+    getStudyMetadata(studyInstanceUid, function(study) {
+        if (!study) {
+            return;
+        }
+        
+        if (sameSeriesAsCurrent(study, currentStudy, modality)) {
+            doneCallback(study);
+            return false;
+        }
+
+        var index = studyInstanceUidList.indexOf(study.studyInstanceUid);
+        studyInstanceUidList.splice(index, 1);
+
+        if (!studyInstanceUidList.length) {
+            return;
+        }
+
+        findMatchingStudies(studyInstanceUidList, currentStudy, modality, doneCallback);
+    });
+}
+
 WindowManager = {
+    init: initialize,
+    setLayout: setLayout,
+    updateWindows: updateWindows,
+    useHangingProtocol: useHangingProtocol,
+    loadSeriesInViewport: loadSeriesInViewport,
     setHangingProtocol: setHangingProtocol,
     getHangingProtocol: getHangingProtocol,
     getNumPresentationGroups: getNumPresentationGroups,
@@ -652,5 +550,3 @@ WindowManager = {
     nextPresentationGroup: nextPresentationGroup,
     previousPresentationGroup: previousPresentationGroup
 };
-
-WindowManager.setHangingProtocol(defaultHangingProtocol);
diff --git a/Packages/viewerbase/package.js b/Packages/viewerbase/package.js
index 12baa7486..8976ca7e0 100644
--- a/Packages/viewerbase/package.js
+++ b/Packages/viewerbase/package.js
@@ -142,10 +142,13 @@ Package.onUse(function(api) {
     api.addFiles('lib/updateAllViewports.js', 'client');
     api.addFiles('lib/exportStudies.js', 'client');
     api.addFiles('lib/encodeQueryData.js', 'server');
+    api.addFiles('lib/modalityDefaultViewport.js', 'client');
+    api.addFiles('lib/hangingprotocols.js', 'client');
 
     //api.export('accountsConfig', 'client');
-    api.export('resizeViewportElements', 'client');
-    api.export('handleResize', 'client');
+    api.export('addMetaData', 'client');
+    api.export('resizeViewportElements','client');
+    api.export('handleResize','client');
     api.export('enableHotkeys', 'client');
     api.export('enablePrefetchOnElement', 'client');
     api.export('displayReferenceLines', 'client');
@@ -161,6 +164,10 @@ Package.onUse(function(api) {
     api.export('updateAllViewports', 'client');
     api.export('exportStudies', 'client');
     api.export('encodeQueryData', 'server');
+    api.export('getMammoHangingProtocolObject', 'client');
+    api.export('getModalityDefaultViewport', 'client');
+    api.export('setModalityDefaultViewportFunction', 'client');
+    api.export('ViewerWindows', 'client');
 
     // Viewer management objects
     api.export('toolManager', 'client');
@@ -209,4 +216,3 @@ Package.onUse(function(api) {
 
     api.export('Services', 'server');
 });
-
diff --git a/Packages/viewerbase/server/services/dimse/studies.js b/Packages/viewerbase/server/services/dimse/studies.js
index 4ebb3d204..e3447410a 100755
--- a/Packages/viewerbase/server/services/dimse/studies.js
+++ b/Packages/viewerbase/server/services/dimse/studies.js
@@ -45,4 +45,4 @@ Services.DIMSE.Studies = function(filter) {
 
     var results = DIMSE.retrieveStudies(parameters);
     return resultDataToStudies(results);
-};
\ No newline at end of file
+};