There are 3 DICOM readers available in Slicer-4.8.1. Could you please try if your data set can be loaded with one of them? In the menu select Edit / Application settings / DICOM / DICOMScalarVolumePlugin / DICOM reader approach, and try GDCM, DCMT, and Archetype.
If loading fails with all three readers then probably there is something wrong with your data. To assist you with diagnosing the issue, please send us what values you have in ImageType, ImagePositionPatient, and ImageOrientationPatient DICOM tags - see instructions here: Problem with sagittal and coronal view from CCTA DICOM files