get_dicom_files.pl cannot find DICOM files with no echo time

[nicolasbrossard]

In IBIS, we have MRI acquisitions that do not have the EchoNumber DICOM tag. They are identified solely using an regex for the series description. However, when the MRI pipeline populates the tarchive_files table, it cannot set the TarchiveSeriesID column, as it needs the echo time to find the corresponding entry in table tarchive_series. As a result, the column is set to NULL and this makes script get_dicom_files.pl unable to extract the DICOM files for these acquisitions.