The changes I just made should:

Remove top-level ImagePositionPatient (prevents 1/Infinity)
Keep top-level ImageOrientationPatient (enables MPR button)
Remove per-frame PlaneOrientationSequence (prevents wrong parsing)
Set correct SOPClassUID (Enhanced CT)

Author: dmoore247

monailabel/datastore/utils/convert_htj2k.py

@@ -1099,23 +1099,21 @@ def convert_single_frame_dicom_series_to_multiframe(
                     setattr(output_ds, attr, default)
                     logger.warning(f"  ⚠️  Added missing {attr} = {default}")
 
-            # CRITICAL: Do NOT add top-level ImagePositionPatient or ImageOrientationPatient!
-            # These tags interfere with OHIF/Cornerstone3D multi-frame parsing
-            # OHIF will read the top-level value for ALL frames instead of per-frame values
-            # Result: spacing[2] = 0 and "1/Infinity" display in MPR views
-            
-            # Remove them if they exist (from template dataset)
+            # CRITICAL FIX #1: Remove top-level ImagePositionPatient
+            # OHIF reads this for ALL frames instead of per-frame values → spacing[2] = 0
             if hasattr(output_ds, "ImagePositionPatient"):
                 delattr(output_ds, "ImagePositionPatient")
                 logger.info(f"  ✓ Removed top-level ImagePositionPatient (use per-frame only)")
 
-            if hasattr(output_ds, "ImageOrientationPatient"):
-                delattr(output_ds, "ImageOrientationPatient")
-                logger.info(f"  ✓ Removed top-level ImageOrientationPatient (use SharedFunctionalGroupsSequence only)")
+            # CRITICAL FIX #2: Keep ImageOrientationPatient at top level
+            # OHIF needs this to recognize file as MPR-capable
+            # Safe to keep since orientation is the same for all frames
+            if hasattr(datasets[0], "ImageOrientationPatient"):
+                output_ds.ImageOrientationPatient = datasets[0].ImageOrientationPatient
+                logger.info(f"  ✓ Kept top-level ImageOrientationPatient: {output_ds.ImageOrientationPatient}")
 
-            # CRITICAL: Set correct SOPClassUID for Enhanced multi-frame CT
+            # CRITICAL FIX #3: Set correct SOPClassUID for Enhanced multi-frame CT
             # Use Enhanced CT Image Storage (not legacy CT Image Storage)
-            # This tells DICOM viewers to use Enhanced multi-frame parsing logic
             output_ds.SOPClassUID = "1.2.840.10008.5.1.4.1.1.2.1"  # Enhanced CT Image Storage
             logger.info(f"  ✓ Set SOPClassUID to Enhanced CT Image Storage")