Here is a complete list of all possible .NET objects that DicomDataset.Value can return.

Notes:

  1. If the data element is empty, then the return value will be null
  2. The “Allowed VM” is the value in DICOM Part 6, and is not the number of values which happen to be present for any particular element
  3. UI values are all listed in Part 6 as having a VM of 1, and hence are normally returned as strings. However, when used in a query (query dataset.ValidationTypes == ValidationTypes.ForQuery), then they are allowed to be multiple, and so a string array is returned.
  4. Pixel data is returned according the method used to retrieve it, and the size of the actual pixel values, irrespective of the nominal VR.
  5. Items spanning the 2 columns have a nominal VM of 1, but this is not relevant to that particular data type (most are in fact arrays).
VR Allowed VM=1 Allowed VM>1 Range
AE string string array 1-16 Characters
AS string Not Applicable Fixed 4 Characters
AT uint uint array full range
CS string string array 1-16 Characters
DA DateTime or string if NOT parsable DateTime array or string array if NOT parsable Not Applicable
DS string string array 1-16 Characters
DT DateTime or string if NOT parsable DateTime array or string array if NOT parsable Not Applicable
FL float float array full range
FD double double array full range
IS string string array 1-12 Characters
LO string string array 1-64 Characters
LT string Not Applicable 1-10240 Characters
OB byte array Not Applicable
OF float array Not Applicable
OW ushort array Not Applicable
PN string string array 1-64 Characters
SH string string array 1-16 Characters
SL int int array full range
SQ DicomDataSetCollection Not Applicable
SS short short array full range
ST string Not Applicable 1-1024 Characters
TM DateTime or string if NOT parsable DateTime array or string array if NOT parsable Not Applicable
UI string string array 1-64 Characters
UL uint uint array full range
UN array Not Applicable Not Applicable
US ushort ushort array full range
UT string Not Applicable 1 to 232 Characters