Merge pull request #158 from blairconrad/bad-privates

Limit private tag anonymization to Mitra global patient ID

Author: blairconrad

src/dicognito/idanonymizer.py

@@ -90,13 +90,11 @@ def _anonymize_mitra_global_patient_id(
         mitra_global_patient_id_element = 0x0020
         if (
             data_element.tag.group == mitra_linked_attributes_group
-            and data_element.tag.element % mitra_global_patient_id_element == 0
+            and data_element.tag.element & 0x00FF == mitra_global_patient_id_element
         ):
             private_tag_group = data_element.tag.element >> 8
-            if (
-                dataset[(mitra_linked_attributes_group << 16) + private_tag_group].value
-                == "MITRA LINKED ATTRIBUTES 1.0"
-            ):
+            element = dataset.get((mitra_linked_attributes_group, private_tag_group), None)
+            if element and element.value == "MITRA LINKED ATTRIBUTES 1.0":
                 # For pydicom 2.2.0 and above (at least to 2.2.2) the Mitra global patient ID tag
                 # can be misidentified as VR IS, instead of its proper LO. This causes
                 # the anonymize action to fail because most values can't be converted.

src/dicognito/release_notes.md

@@ -3,6 +3,7 @@
 
 ### Fixed
 - Version table format has bad separator ([#147](https://github.com/blairconrad/dicognito/issues/147))
+- Private creator 0031,0020 breaks anonymization ([#157](https://github.com/blairconrad/dicognito/issues/157))
 
 ## 0.16.0a1
 

tests/test_anonymize_private_tags.py

@@ -1,4 +1,5 @@
 from dicognito.anonymizer import Anonymizer
+from pydicom import Dataset
 
 from .data_for_tests import load_dcm
 
@@ -16,3 +17,29 @@ def test_mitra_global_patient_id_is_updated():
         actual = block[0x20].value
 
         assert actual != "GPIYMBB54"
+
+
+def test_0031_0040_is_not_updated():
+    with Dataset() as dataset:
+        dataset.ensure_file_meta()
+        dataset.add_new(0x00310040, "LO", "Some value")
+        expected = dataset[0x0031, 0x0040]
+
+        anonymizer = Anonymizer()
+        anonymizer.anonymize(dataset)
+
+        actual = dataset[0x0031, 0x0040]
+        assert actual == expected
+
+
+def test_private_creator_0031_0020_is_not_updated():
+    with Dataset() as dataset:
+        dataset.ensure_file_meta()
+        dataset.add_new(0x00310020, "LO", "Another value")
+        expected = dataset[0x0031, 0x0020]
+
+        anonymizer = Anonymizer()
+        anonymizer.anonymize(dataset)
+
+        actual = dataset[0x0031, 0x0020]
+        assert actual == expected