diff --git a/Examples/DICOMRTTool_Tutorial.ipynb b/Examples/DICOMRTTool_Tutorial.ipynb
index ea299ae..99b9864 100644
--- a/Examples/DICOMRTTool_Tutorial.ipynb
+++ b/Examples/DICOMRTTool_Tutorial.ipynb
@@ -550,6 +550,16 @@
     "# Since we haven't defined anything yet, it prompts you to input a list of contour names"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "Dicom_reader.which_indexes_lack_all_rois() # Check to see which indexes LACK all of the rois we want\n",
+    "# Since we haven't defined any wanted ROI yet, it will prompt you to input a list of contour names"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -1644,7 +1654,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3",
+   "display_name": "Python 3 (ipykernel)",
    "language": "python",
    "name": "python3"
   },
@@ -1658,7 +1668,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.8"
+   "version": "3.8.10"
   }
  },
  "nbformat": 4,