DICOM PS3.18 2019a - Web Services

F.2.5 DICOM JSON Model Null Values

If an attribute is present in DICOM but empty (i.e., Value Length is 0), it shall be preserved in the DICOM JSON attribute object containing no "Value", "BulkDataURI" or "InlineBinary".

If a multi-valued attribute has one or more empty values these are represented as "null" array elements. For example:

"Value": [ "bar", null, "foo" ]

If a sequence contains empty items these are represented as empty JSON object in the array.

"Value": [ { … }, { }, { … } ]
DICOM PS3.18 2019a - Web Services