The data is organized in three layers. 
The first layer of directories follows the naming convention YYYY-MM-DD_P[1-3], denoting the day of the session. 
The number after the P denotes which imaging session of the day it was. 
Inside each folder there are three subfolders named: Nav_+_Data, Nav_Pur_1 und Nav_Pur_2 all of which containing the DICOM images.
The first contains the interleaved sequences. Both other folders contain a reference navigator sequence each.  

The file names contain the following parts: PPPP_XXX_XXXX.MR.GULAMHUSSENE_LEBER.SSSS.NNNN.YYYY.MM.DD
PPPP                      is an anonymize subject ID
MR.GULAMHUSSENE_LEBER     is the name of the study
SSSS                      is the sequence number
NNNN                      is the image number in the sequence
YYYY.MM.DD                is the date of acquisition

The interleaved sequences are an alternating succession of navigator and data frames. Each data frame was imaged 200ms after the previous and 200ms before the following navigator frame. 
Each interleaved  sequence images another data slice. 
The navigator frames in the interleaved as well as in the reference sequences are imaged in the same slice position (scanner coordinates).