From c6b28654b507981d1dc5038b4f8a869ed53470fe Mon Sep 17 00:00:00 2001
From: Joe Boccanfuso <109477394+jbocce@users.noreply.github.com>
Date: Fri, 16 May 2025 13:33:57 -0400
Subject: [PATCH] fix(segmentation): segmentation stats calculations were not
 being done on a subsequent navigation to a mode (#5046)

---
 extensions/cornerstone/src/index.tsx          | 20 ++++---
 extensions/cornerstone/src/init.tsx           | 57 ------------------
 .../utils/setUpSegmentationEventHandlers.ts   | 60 +++++++++++++++++++
 3 files changed, 72 insertions(+), 65 deletions(-)
 create mode 100644 extensions/cornerstone/src/utils/setUpSegmentationEventHandlers.ts

diff --git a/extensions/cornerstone/src/index.tsx b/extensions/cornerstone/src/index.tsx
index 9f3ccc943..bcc6f785a 100644
--- a/extensions/cornerstone/src/index.tsx
+++ b/extensions/cornerstone/src/index.tsx
@@ -56,6 +56,7 @@ import { StudySummaryFromMetadata } from './components/StudySummaryFromMetadata'
 import CornerstoneViewportDownloadForm from './utils/CornerstoneViewportDownloadForm';
 import utils from './utils';
 import { useMeasurementTracking } from './hooks/useMeasurementTracking';
+import { setUpSegmentationEventHandlers } from './utils/setUpSegmentationEventHandlers';
 export * from './components';
 
 const { imageRetrieveMetadataProvider } = cornerstone.utilities;
@@ -91,9 +92,16 @@ const cornerstoneExtension: Types.Extensions.Extension = {
    */
   id,
 
-  onModeEnter: ({ servicesManager }: withAppTypes): void => {
+  onModeEnter: ({ servicesManager, commandsManager }: withAppTypes): void => {
     const { cornerstoneViewportService, toolbarService, segmentationService } =
       servicesManager.services;
+
+    const { unsubscriptions: segmentationUnsubscriptions } = setUpSegmentationEventHandlers({
+      servicesManager,
+      commandsManager,
+    });
+    unsubscriptions.push(...segmentationUnsubscriptions);
+
     toolbarService.registerEventForToolbarUpdate(cornerstoneViewportService, [
       cornerstoneViewportService.EVENTS.VIEWPORT_DATA_CHANGED,
     ]);
@@ -144,6 +152,8 @@ const cornerstoneExtension: Types.Extensions.Extension = {
     segmentationService.removeAllSegmentations();
 
     unsubscriptions.forEach(unsubscribe => unsubscribe());
+    // Clear the unsubscriptions
+    unsubscriptions.length = 0;
   },
 
   /**
@@ -163,13 +173,7 @@ const cornerstoneExtension: Types.Extensions.Extension = {
     const { syncGroupService } = servicesManager.services;
     syncGroupService.registerCustomSynchronizer('frameview', createFrameViewSynchronizer);
 
-    const initResult = await init.call(this, props);
-
-    unsubscriptions.push(...initResult.unsubscriptions);
-
-    return {
-      ...initResult,
-    };
+    await init.call(this, props);
   },
   getToolbarModule,
   getHangingProtocolModule,
diff --git a/extensions/cornerstone/src/init.tsx b/extensions/cornerstone/src/init.tsx
index a3b12ee74..4b73e8cd9 100644
--- a/extensions/cornerstone/src/init.tsx
+++ b/extensions/cornerstone/src/init.tsx
@@ -39,10 +39,6 @@ import { useLutPresentationStore } from './stores/useLutPresentationStore';
 import { usePositionPresentationStore } from './stores/usePositionPresentationStore';
 import { useSegmentationPresentationStore } from './stores/useSegmentationPresentationStore';
 import { imageRetrieveMetadataProvider } from '@cornerstonejs/core/utilities';
-import {
-  setupSegmentationDataModifiedHandler,
-  setupSegmentationModifiedHandler,
-} from './utils/segmentationHandlers';
 
 const { registerColormap } = csUtilities.colormap;
 
@@ -199,18 +195,6 @@ export default async function init({
     });
   });
 
-  // Setup segmentation event handlers
-  const { unsubscribe: unsubscribeSegmentationDataModifiedHandler } =
-    setupSegmentationDataModifiedHandler({
-      segmentationService,
-      customizationService,
-      commandsManager,
-    });
-
-  const { unsubscribe: unsubscribeSegmentationModifiedHandler } = setupSegmentationModifiedHandler({
-    segmentationService,
-  });
-
   // When a custom image load is performed, update the relevant viewports
   hangingProtocolService.subscribe(
     hangingProtocolService.EVENTS.CUSTOM_IMAGE_LOAD_PERFORMED,
@@ -317,47 +301,6 @@ export default async function init({
 
   // Call this function when initializing
   initializeWebWorkerProgressHandler(servicesManager.services.uiNotificationService);
-
-  const { unsubscribe: unsubscribeSegmentationCreated } = segmentationService.subscribe(
-    segmentationService.EVENTS.SEGMENTATION_ADDED,
-    evt => {
-      const { segmentationId } = evt;
-      const displaySet = displaySetService.getDisplaySetByUID(segmentationId);
-      if (displaySet) {
-        return;
-      }
-
-      const segmentation = segmentationService.getSegmentation(segmentationId);
-      const label = segmentation.cachedStats.info;
-      const imageIds = segmentation.representationData.Labelmap.imageIds;
-
-      // Create a display set for the segmentation
-      const segmentationDisplaySet = {
-        displaySetInstanceUID: segmentationId,
-        SOPClassUID: '1.2.840.10008.5.1.4.1.1.66.4',
-        SOPClassHandlerId: '@ohif/extension-cornerstone-dicom-seg.sopClassHandlerModule.dicom-seg',
-        SeriesDescription: label,
-        Modality: 'SEG',
-        numImageFrames: imageIds.length,
-        imageIds,
-        isOverlayDisplaySet: true,
-        label,
-        madeInClient: true,
-        segmentationId: segmentationId,
-        isDerived: true,
-      };
-
-      displaySetService.addDisplaySets(segmentationDisplaySet);
-    }
-  );
-
-  const unsubscriptions = [
-    unsubscribeSegmentationDataModifiedHandler,
-    unsubscribeSegmentationModifiedHandler,
-    unsubscribeSegmentationCreated,
-  ];
-
-  return { unsubscriptions };
 }
 
 function initializeWebWorkerProgressHandler(uiNotificationService) {
diff --git a/extensions/cornerstone/src/utils/setUpSegmentationEventHandlers.ts b/extensions/cornerstone/src/utils/setUpSegmentationEventHandlers.ts
new file mode 100644
index 000000000..678ce2229
--- /dev/null
+++ b/extensions/cornerstone/src/utils/setUpSegmentationEventHandlers.ts
@@ -0,0 +1,60 @@
+import {
+  setupSegmentationDataModifiedHandler,
+  setupSegmentationModifiedHandler,
+} from './segmentationHandlers';
+
+export const setUpSegmentationEventHandlers = ({ servicesManager, commandsManager }) => {
+  const { segmentationService, customizationService, displaySetService } = servicesManager.services;
+
+  const { unsubscribe: unsubscribeSegmentationDataModifiedHandler } =
+    setupSegmentationDataModifiedHandler({
+      segmentationService,
+      customizationService,
+      commandsManager,
+    });
+
+  const { unsubscribe: unsubscribeSegmentationModifiedHandler } = setupSegmentationModifiedHandler({
+    segmentationService,
+  });
+
+  const { unsubscribe: unsubscribeSegmentationCreated } = segmentationService.subscribe(
+    segmentationService.EVENTS.SEGMENTATION_ADDED,
+    evt => {
+      const { segmentationId } = evt;
+      const displaySet = displaySetService.getDisplaySetByUID(segmentationId);
+      if (displaySet) {
+        return;
+      }
+
+      const segmentation = segmentationService.getSegmentation(segmentationId);
+      const label = segmentation.cachedStats.info;
+      const imageIds = segmentation.representationData.Labelmap.imageIds;
+
+      // Create a display set for the segmentation
+      const segmentationDisplaySet = {
+        displaySetInstanceUID: segmentationId,
+        SOPClassUID: '1.2.840.10008.5.1.4.1.1.66.4',
+        SOPClassHandlerId: '@ohif/extension-cornerstone-dicom-seg.sopClassHandlerModule.dicom-seg',
+        SeriesDescription: label,
+        Modality: 'SEG',
+        numImageFrames: imageIds.length,
+        imageIds,
+        isOverlayDisplaySet: true,
+        label,
+        madeInClient: true,
+        segmentationId: segmentationId,
+        isDerived: true,
+      };
+
+      displaySetService.addDisplaySets(segmentationDisplaySet);
+    }
+  );
+
+  const unsubscriptions = [
+    unsubscribeSegmentationDataModifiedHandler,
+    unsubscribeSegmentationModifiedHandler,
+    unsubscribeSegmentationCreated,
+  ];
+
+  return { unsubscriptions };
+};