See T7285. Restructuring of the DicomSeriesReader has now some improved aspects. However, the handling of 3D+t data is not nicely implemented.
DicomSeriesReader::SortIntoBlocksFor3DplusT could be implemented in asimpler way, because the method how GetSeries sorts its output has changed a little.
Esp. the call to SortSeriesSlices should be made optional again to be more efficient.
Tests from T3700 should be used to verify that implementation logic has not changed.