diff --git a/atlas/models.py b/atlas/models.py
index 688e4983..1074c39a 100644
--- a/atlas/models.py
+++ b/atlas/models.py
@@ -528,7 +528,7 @@ class Series(SeriesBase):
             #    instances.append(image.get_image_dicom_json(image_index))
 
         description = f"{self.examination} ({self.plane})"
-        if self.contrast:
+        if self.contrast and self.contrast is not None:
             description = f"{description} / {self.contrast}"
         series_json["SeriesDescription"] = description
         series_json["instances"] = instances