From 1aa443112186851855a638ab974a3060c3e28ea0 Mon Sep 17 00:00:00 2001
From: Belbin-GK <150322972+Belbin-GK@users.noreply.github.com>
Date: Thu, 4 Dec 2025 02:06:30 +0530
Subject: [PATCH] fix: skip VOI sync for empty viewports (#5599)

Co-authored-by: trenser-belbin <belbin.kunjumon@prenuvo.com>
---
 extensions/cornerstone/src/utils/toggleVOISliceSync.ts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/extensions/cornerstone/src/utils/toggleVOISliceSync.ts b/extensions/cornerstone/src/utils/toggleVOISliceSync.ts
index a571fe8e6..11cc347a5 100644
--- a/extensions/cornerstone/src/utils/toggleVOISliceSync.ts
+++ b/extensions/cornerstone/src/utils/toggleVOISliceSync.ts
@@ -84,6 +84,10 @@ function groupViewportsByModality(
   return viewportsArray.reduce((acc, viewport) => {
     const { displaySetInstanceUIDs } = viewport;
     // Todo: add proper fusion support
+    // Fix: Skip processing if the viewport is empty.
+    if (!displaySetInstanceUIDs?.length) {
+      return acc;
+    }
     const displaySetInstanceUID = displaySetInstanceUIDs[0];
     const displaySet = displaySetService.getDisplaySetByUID(displaySetInstanceUID);