How to scan forparametric cells?

Hi,

To scan a drawing for all cells I use:

 ElementScanCriteria scanCriteria = new ElementScanCriteriaClass();
      scanCriteria.ExcludeAllTypes();
      scanCriteria.IncludeType(MsdElementType.CellHeader);

but this don't find any parametric cells and I didn't find any other includedType() which can be used to find parametric cells?

Any ideas?

Thanks for help

Markus