From a0556b08be98e0bba950ad7b9b575d7b971104ba Mon Sep 17 00:00:00 2001
From: Joe Boccanfuso <109477394+jbocce@users.noreply.github.com>
Date: Wed, 5 Nov 2025 12:00:41 -0500
Subject: [PATCH] fix(segmentation): When synchronizing a segmentation
 representation, use the type of the source viewport segmentation to determine
 the type of the target viewport segmentation (#5546)

---
 .../createHydrateSegmentationSynchronizer.ts                 | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/extensions/cornerstone/src/services/SyncGroupService/createHydrateSegmentationSynchronizer.ts b/extensions/cornerstone/src/services/SyncGroupService/createHydrateSegmentationSynchronizer.ts
index f20bbd6b8..8bebf6439 100644
--- a/extensions/cornerstone/src/services/SyncGroupService/createHydrateSegmentationSynchronizer.ts
+++ b/extensions/cornerstone/src/services/SyncGroupService/createHydrateSegmentationSynchronizer.ts
@@ -43,7 +43,7 @@ const segmentationRepresentationModifiedCallback = async (
 ) => {
   const event = sourceEvent as ToolsTypes.EventTypes.SegmentationRepresentationModifiedEventType;
 
-  const { segmentationId } = event.detail;
+  const { segmentationId, type: segmentationRepresentationType } = event.detail;
   const { segmentationService } = servicesManager.services;
 
   const targetViewportId = targetViewport.viewportId;
@@ -69,7 +69,8 @@ const segmentationRepresentationModifiedCallback = async (
   const type: Enums.SegmentationRepresentations =
     viewport.type === CoreEnums.ViewportType.VOLUME_3D
       ? Enums.SegmentationRepresentations.Surface
-      : Enums.SegmentationRepresentations.Labelmap;
+      : ((segmentationRepresentationType as Enums.SegmentationRepresentations) ??
+        Enums.SegmentationRepresentations.Labelmap);
 
   await segmentationService.addSegmentationRepresentation(targetViewportId, {
     segmentationId,